Дисертації з теми "Geochemical exploration"
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1
Krug, Mark Alan. "Geochemical exploration in calcrete terrains." Thesis, Rhodes University, 1995. http://hdl.handle.net/10962/d1006891.
Повний текст джерелаАнотація:
This work takes a look at some of the literature on calcretes and especially the problem of geochemical exploration in calcrete terrains. The conclusion that will be reached is that exploration in calcrete terrains is not futile and that provided the explorationist is aware of the types of calcrete and their genetic implications calcrete can be used as a sampling medium and anomalies can be detected through calcrete (p.1.)KMBT_363
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2
Fotakis-Tsipouras, Constantine. "Geochemical exploration studies in the Lavrion (Laurium) area of Greece." Thesis, University of Leicester, 1986. http://hdl.handle.net/2381/35027.
Повний текст джерелаАнотація:
Detailed geochemical studies of the dispersion patterns of selected elements (Cu, Pb, Zn, Ag, Mn, As, Fe, Ni, Co) were undertaken in the drainage sediments and soils in the Lavrion peninsula with the objective of demonstrating the application of geochemical techniques to the search for previously unknown mineral deposits. The study area comprises three geological units; the Anavissos, Kamareza and Plaka, each with its distinct stratigraphy and structural history. The Kamareza and Anavissos units are separated by the Legraina fault, while the overlying Plaka unit is separated from these underlying two units by an unconformity. Both geological and geochemical data indicate that karstic mixed sulphide mineralization is largely restricted in the Kamareza and Plaka units. An area of approximately 65 square kilometres was chosen for detailed stream sediment, soil, rock and bigeochemical studies. Digestion of 0.2 gms. Of minus 80-mesh material in 25% (HNO3 at 90°C) for 4 hours appeared to provide the optimum technique for dissolution of elements such as Cu, Pb, Zn, Mn, Fe and Ni. Analysis was performed by AAS for all these elements. Arsenic was also determined by the cold extraction method (James, 1957). The data obtained were treated by graphical, univariate and multivariate statistical techniques including histograms, bar-diagrams, graphs, frequency distribution analysis, moving averages, correlation coefficient, factor and regression analysis. Other properties including pH, conductivity, organic matter content and CaCO3, and both Fe-and Mn-oxide concentrations, were also investigated in order to establish their influence on the distribution patters of the various elements. It was demonstrated that within the study area mechanical dispersion dominates over chemical. In spite of contamination from extensive past mining activity, geochemical stream and soil surveys produce reliable distribution patterns in the Mediterranean environment of Lavrion. The occurrence of previously unknown mineralization was proven by trenching in target areas indicated by geochemical patterns. Biochemical surveys were also found to yield useful information, although they are time consuming and suffer from problems associated with the uneven distribution of plant species.
3
Hartzler, Joy R. "The geological exploration of kimberlitic rocks in Québec /." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101135.
Повний текст джерелаАнотація:
Diamonds have been discovered in a variety of potassic ultramafic rocks including group-I and group-II kimberlites, olivine lamproites and aillikites, all of which are macroscopically similar and can be difficult to differentiate when viewed under the microscope. However, group-I kimberlites, and to a much lesser extent group-II kimberlites and olivine lamproites, are known to contain economic concentrations of diamonds. This study addresses the problem of distinguishing among different types of kimberlitic and related rocks by developing a geochemically-based method for classifying them.Geochemical methods have been largely ignored in the classification of kimberlites and related rock types due to high concentrations of xenoliths. However, this problem can be largely overcome by only selecting matrix material for analysis. An evolving kimberlitic magma will become enriched or improvished in Si due to the fractionation of olivine and phlogopite, depending on the initial Si concentration of the magma. As they have low Si concentrations, group-I kimberlites and aillikites can be separated from group-II kimberlites and meimechites, which have higher Si concentrations for any Mg content. Furthermore, since aillikites and meimechites are relatively rich in Fe compared to group-I and group-II kimberlites, these rock types form four separate fields on a Si vs. Fe discrimination diagram. Similar rock-type separation is observed when the ratio of La to Yb is plotted against the ratio of Sm to Yb. Kimberlite and other potassic ultramafic rocks were sampled from nine areas in Quebec: the Otish Mountains, Wemindji, Torngat Mountains, Desmaraisville, Temiscamingue, Ile Bizard, Lac Leclair, Baie James and Ayer's Cliff regions. Major and selected trace element concentrations were determined by XRF analysis for all samples, while a subset of representative samples was selected for trace element analysis by ICP-MS. Electron microprobe analyses of unaltered olivine and phlogopite were also conducted.
Of the 37 samples that were classified both mineralogically and chemically, 23 or 62% were correctly classified using Fe and Si. This number increases to 84%, if the REE are used in conjunction with Si and Fe. The Si vs. Fe discrimination diagram separates group-I kimberlite from most aillikite and meimechite rocks and group-II kimberlite/olivine lamproite rocks from most aillikite and meimechite rocks. Therefore, major and trace element geochemistry offers an important tool for the classification of kimberlitic rocks.
Vasilenko et al. (2002) and Francis (2003) both suggested that diamond grades can be correlated with the major element compositions of the kimberlites. The data collected in this study confirm the inverse relationship between TiO2 concentration and diamond grade. The lowest TiO 2 values were obtained on samples from the Otish Mountains and Renard samples in particular. Other areas of Quebec are characterized by higher TiO2 contents with most samples containing greater than 2 wt% TiO 2. Therefore, the kimberlitic rocks from the Renard locality have the greatest potential for an economic diamond deposit. The origin of this correlation needs to be explored, however, because it is unclear whether this is a feature of the mantle source, or reflects the survivability of diamonds within the kimberlites.
4
Dalrymple, Iain Faculty of Science UNSW. "An approach to the optimisation of partial extractions for use in geochemical exploration." Awarded by:University of New South Wales, 2007. http://handle.unsw.edu.au/1959.4/40473.
Повний текст джерелаАнотація:
Geochemical exploration for mineral deposits has generally been restricted to regions dominated by residual regolith or where transported regolith cover is thin. A variety of partial geochemical extraction techniques, linked to new predictive models for element migration through transported regolith cover, have demonstrated a potential to detect deeply buried mineralisation under certain circumstances. Problems with the reliability and further development of such partial extractions are linked to the lack of information on either the form of metals or the factors that control the extraction of metals from regolith materials. This study quantitatively examines the mechanisms of a range of partial extraction methods, based on a suite of surface regolith samples from the Mandamah Cu-Au deposit that is covered by 50m of transported regolith. Samples at were subjected to acetate, hydroxylamine.HCI and Na-pyrophosphate extractions at various reagent concentrations, pH values, temperatures and durations, following various sample preparation and chemical pretreatment permutations. The data were modelled, and reaction conditions subsequently optimized, on the basis of central composite designs. Conventional partial extraction (acetate, hydroxylamine and aqua regia) data, displayed high variability for some major and trace metals surrounding the periphery of mineralisation at Mandamah but little indication of direct vertical migration of ore-related metals. The buffered acetate extraction is primarily controlled by the capacity of the solution to generate acid rather than exchange induced by the cation ofthe acetate salt. Trace metals were highly susceptible to readsorption effects. Acidic hydroxylamine extraction is driven by kinetically limited acid hydrolysis and the hydroxylamine concentration has little effect on metal extractability. Alkaline Na-pyrophosphate extraction proved difficult to model. Two new partial extractions developed in this study - alkaline hydroxylamine.HCI and pH-static calcium nitrate - offer a different functionality to conventional extractions and provide more coherent geochemical patterns at Mandamah related to the location of buried mineralisation. These patterns are also related to the capacity of samples to resist pH neutralization. Systematic optimisation of geochemical extraction procedures is demonstrated to be an effective approach to improving detection of geochemical patterns in surface regolith that can be spatially related to the effects of mineralisation on the chemistry and mineralogy of overlying transported regolith cover.
5
Ackerman, Benjamin R. "Regolith geochemical exploration in the Girilambone District of New South Wales." Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20051027.095334/index.html.
Повний текст джерела
6
Chiconela, Domingos Rubão. "Geochemical exploration in tropical terrains with special reference to base metals." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005565.
Повний текст джерелаАнотація:
In tropical areas, the high rainfall induces severe-and pervasive weathering, producing a thick soil cover. The lithologies underneath may b~ recognised using geochemical mapping, which is based on certain elements that have the ability to differentiate between various lithologic units. Elements that are independent of the weathering process are normally selected for this purpose. The chemistry of mobility of base metals is an important factor to take into account when evaluating the mobility and distribution of these elements in a soil profile. Factors such as pH, Eh, organic material, clay minerals, Fe and Mn oxides are normally key aspects to be considered. When iron-rich rocks undergo deep weathering, lateritic profiles are developed. These are widespread in a belt bordering the equatorial zone, including the Brazilian shield, West and East Africa, parts of India and Northern Australia. In these profiles, the high rainfall promotes intense leaching of the different horizons. Where the pre-existing profiles are mostly preserved, the base metals are distributed throughout the profile: in the upper ferruginous horizon, goethite and hematite can adsorb large amounts of Mo, resulting in large dispersion halo. Other base metals such as Cu and Zn are less resistant in these freely-drained profiles and, therefore, they may be partly leached from the profile. In the lower horizons, Cu, ,zn, Ni and Co are retained, hosted in kaolinite and smectite, and thus, a high geochemical contrast will be identified in this horizon at the expense of a decline in the size of the dispersion haloes. The pre-existing profiles can be truncated, with a thin stone line developing at the contact between the lateritic profile and the recent soil. The conditions in these environments favour the retention of most of the pathfinder and target elements in all soil horizons, with the B horizon showing the highest contrast. If the primary rock is rich in AI, a bauxitic profile will be developed. The world distribution of bauxites closely resembles that of laterites. The behaviour of Co and Ni is very similar to that of iron during the bauxitization. Furthermore, the factors that induce residual enrichment of Al with removal of Fe in the soil profile will cause significant depletion of Co and Ni in these profiles. These metals are then concentrated at the base of the profile because of precipitation from downward percolating solutions. Many karst bauxite deposits in Southern Europe are enriched with Ni and Co in the basal horizon. Such horizon is mined as nickel ore in the bauxites of the Lokris region in Greece. Copper and molybdenum are strongly enriched.in bauxitic profiles. Concentration ratios are 8 and 3.2 for Cu and Mo respectively. Molybdenum is closely related to goethite and hematite, and therefore, the high concentration of Mo in a bauxitic profile will be consistent with the horizon where iron is concentrated. Copper concentrates at the base of the iron rich-horizon but also appears enriched in the saprolite together with Co. When sulphide bodies occur, in this environment, deep and penetrative weathering has resulted in considerable near-surface mobilization of iron and silica. The supergene alteration commonly obscures the identity of the primary sulphides at the surface. In this case, geochemical assessment of the resulting gossan has proved to be crucial in mineral exploration. A search in the secondary mineral assemblage, volatile and precious metals may lead to the information on the composition of the primary sulphide assemblage. The conclusion that will be reached is that if the geochemical properties (mobility, affinities with Fe or Mn oxides and/or clay minerals) of each of the base metals are understood, an appropriate sampling (optimum size-depth combination) will then be done. In such cases, a subdued, weak, but significant, geochemical response will be identified in the surface horizon.
7
Mwenze, Tshipeng. "The use of chemostratigraphy and geochemical vectoring as an exploration tool for platinum group metals in the Platreef, Bushveld Igneous Complex, South Africa: a case study on the sandsloot & overysel farms." University of the Western Cape, 2014. http://hdl.handle.net/11394/4460.
Повний текст джерелаАнотація:
>Magister Scientiae - MScThe paucity of geochemical criteria for stratigraphic correlations and defining the styles of mineralisation pose serious problems in locating PGE-rich zones in the Platreef. This study is therefore aimed at identifying and appraising process-based mineralogical/geochemical criteria which may be useful in stratigraphic correlations and characterizing the nature and styles of PGE mineralisation. In addition, the work investigated the possible use of geochemical vectoring as a tool to locate the PGE-rich zones. Boreholes OY 482 and SS 330, drilled at the Overysel and Sandsloot farms respectively, were logged, and a total of 119 quarter cores were sampled for petrographic studies. The elemental contents in the rocks were determined by XRF and ICP-OES analyses and were evaluated using various statistical and mass balance techniques. In borehole OY 482, where the floor rock is Archaean granite, the Platreef consists of three feldspathic pyroxenite sills referred to as Lower, Middle and Upper Platreef units, from the bottom to the top, respectively. The results show that the Lower and Upper Platreef units have higher median values of Mg# (0.58 and 0.57) and Ni/Cu (0.68 and 0.75) when compared to the Middle Platreef (Mg#: 0.54 and Ni/Cu: 0.67) which may not be totally suggestive of two magmatic intrusive pulses. In borehole SS 330, where the floor rock is dolomite, the rocks consist of clinopyroxenites and olivine clinopyroxenites (variably serpentinised). These two units are intercalated with each other and are products resulting from the injection of Platreef magma sills within the dolomite floor rock. The hierarchical clustering and mass balance calculations show that when compared to the Platreef feldspathic pyroxenites, which have higher SiO2, Al2O3 and Fe2O3 median contents, the clinopyroxenites possess higher CaO median content whereas the olivine clinopyroxenites have higher MgO and LOI median contents. The PGE-rich zones (i.e. Pt+Pd) in clinopyroxenites are marked by low Ca/Mg median values, whereas in both, the olivine clinopyroxenites and the Platreef units, these zones are marked by high Mg/Fe median values. The suggested base metal index [(Cu/Zn) x (Ni/Co)] used to vector towards PGE-rich zones, which reflects the presence of the base metal sulphides (BMS), correlates with the Pt+Pd in the BMS-rich zones. This is not always the case in zones of low BMS contents which may reflect changes in the mineralogy of the BMS. In conclusion, the two boreholes studied show contrasting petrographic and geochemical attributes. This dissimilarity is mainly due to the fact that borehole OY 482 comprises Platreef magmatic rocks whereas borehole SS 330 intersected metamorphic/ metasomatic rocks.
8
Breedt, Machiel Christoffel. "Gold exploration in tropical and sub-tropical terrains with special emphasis on Central and Western Africa." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005578.
Повний текст джерелаАнотація:
The aim of this dissertation is an attempt to' provide a general guide for future gold exploration in tropical and sub-tropical terrains. The dissertation includes a brief discussion of the various exploration techniques used in regional and local exploration. This provide the necessary background knowledge to discriminate between the constraints and applications and to be able to select the techniques which are more suitable for gold exploration in tropical and sub-tropical terrains. Weathering, gold geochemistry and soil formation, fields often neglected, are emphasized to illustrate the importance of the mobility and dispersion of gold in the weathering of the lateritic soil profile. A sound knowledge and experience in regolith mapping is to the advantage of the explorationist. Case studies with special emphasis on Central- and Western Africa are included to illustrate the effectiveness of some of the gold exploration techniques in tropical and sub-tropical terrains. Gold exploration is a highly complex and demanding science and to be successfull involves the full intergration of all geological, geochemical and geophysical information available. An intergrated exploration method and strategy would enhance the possibility of making viable discoveries in this highly competative environment where our mineral resources become more depleted every day. Where applicable, the reader is refered to various recommended literature sources to provide the necessary background knowledge which form an integral part of gold exploration.
9
Shiva, Mohammad. "A stream sediment geochemical exploration in the arid environment of east Iran." Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243344.
Повний текст джерела
10
Hansen, Robert N. (Robert Neill). "The evaluation of whole-rock and partial leach geochemical exploration techniques applied to the exploration for tanzanite deposits : Merelani, North-Eastern Tanzania." Thesis, Stellenbosch : Stellenbosch University, 2007. http://hdl.handle.net/10019.1/21455.
Повний текст джерелаАнотація:
Thesis (MSc)--University of Stellenbosch, 2007.ENGLISH ABSTRACT: The aim of the study is to ascertain whether geochemical exploration techniques can be used in the search for tanzanite deposits in the Merelani area, NE Tanzania. Previous studies have successfully demonstrated a partial extraction method (in situ soil leaching) in identifying prospective ultramafic bodies at the Rockland ruby mine in the Mangare area, Kenya, thereby demonstrating the usefulness of geochemical methods in gemstone exploration. In this study, a partial extraction as well as a whole-rock geochemical method was used to determine the applicability of these methods in prospecting for tanzanite mineralisation using different sampling media, such as soil, stream sediment and calcrete. It is possible that this geochemical approach may not be as effective as physical methods such as the separation and examination of heavy mineral suites. However, its viability needs to be evaluated due to the potential efficiency and relative logistic ease of the method. In essence the scientific method employed is to compare overburden (soils, stream sediments and calcrete) chemistry with known underlying geology, the latter having been established via diamond core drilling. A positive correlation would allow the prediction of overburden covered tanzanite mineralisation. Soil samples were collected from a trench dug perpendicular to regional lithological strike over both barren and tanzanite-bearing horizons. XRF trace element data for the soils was compared to the chemistry of the underlying lithologies. ICP-AE data derived from 1 molar HCL soil leachate (12 hour leach) and soil XRF data, from the same samples, was compared, using a mass balance index, to discern any hydromorphic dispersion of selected trace elements and to evaluate the leachate as a viable alternative to XRF analysis. In general, a good correlation exists between the soil and rock trace element data profiles over the length of the section. However, Ti- and Zr-normalised mass balance calculations show some down-hill drift, but this does not disrupt the overall pattern. The ICP-AE acid leach data show that hydromorphic dispersion is low, that the trace elements of interest (V, Cr, Ni and Cu) are hosted within non-soluble phases. Consequently, the leach technique is not a viable alternative to XRF analysis of the soils. XRF analysis of the soils was shown to be potentially useful in identifying new areas of mineralisation as the soils overlying a graphitic calc-silicate schist, that always occurs adjacent to the tanzanite mineralisation in the Merelani area, was found to be easily identifiable based on anomalous concentrations of V. An exploration concession was chosen for stream sediment sampling on the basis of the presence of large streams, of a few tsavorite mines indicating high prospectivity for tanzanite, and because of a variation in geology on the property. Tanzanite and tsavorite are cogenetic in the known tanzanite deposits. In this case the aim was to investigate the possible occurrence of tanzanite-like geochemical anomolies (i.e. the anomalous V observed in the soil chemistry investigation) could be detected in the vicinity of the tsavorite mines. Tsavorite, the gem variety of grossular garnet, also contains high concentrations of V. The samples were analysed by XRF whole-rock methods for trace element content. The data shows a number of clear positive V anomalies in the study area. The data also shows that each of the existing or abandoned mines in the area is marked by a positive V anomaly. This section of the study also demonstrated a relatively low degree of stream sediment dispersion of the trace elements of interest – most likely a function of the semi-arid climate. The fine fraction (<90μm), however was shown to be mobilised to a relatively larger degree than the coarse (180μm – 300μm) and medium (90μm - 180μm) fractions. As is predictable from the leachate analysis, factor analysis of the data shows that the trace elements are dominated by heavy mineral geochemistry and that a study in heavy mineral exploration might provide a cheaper and more viable option to those explored in this study. Calcrete samples were taken from an abandoned, 10m deep mine shaft, which was sunk through the calcrete to reach the tanzanite deposit. The shaft was sampled from the bottom, closest to the tanzanite mineralisation, to the surface to investigate the association between trace element geochemistry and proximity to the deposit. There was no vertical association between the trace element geochemistry of the calcrete and proximity to the tanzanite deposit. There was also no clear indication in the geochemistry of the calcrete of the existence of the tanzanite deposit beneath it. This further indicates the immobility of the elements of interest in this environment. This study has demonstrated that properly constrained soil and stream sediment geochemical studies may be of use in tanzanite exploration. However, it must be stressed that this is only the case if the geochemical signature of the lithological package associated with the mineralisation is unique and well known.
AFRIKAANSE OPSOMMING: Die doel van hierdie studie is om te bepaal of geochemiese eksplorasie tegnieke vir die soek na tanzaniet afsettings in die Merelani area, noord-oos Tanzanië, gebruik kan word. Voorige studies het gewys dat ‘n gedeeltelike ekstraksie metode (in situ grond looging) gebruik kon word om prospektiewe ultramafiese liggame by the Rockland rubyn myn in die Mangare area, Kenia te identifiseer. Hierby is gedemonstreer dat geochemiese eksplorasie metodes suksesvol in edelsteen eksplorasie toegepas kan word. In hierdie studie is ‘n gedeeltelike ekstrasksie en heel-rots geochemiese metodes gebruik om die toepaslikheid van hierdie metodes op tanzaniet eksplorasie te toets. Verskillende geologiese materiale is gemonster, naamlik grond, stroom sedimente en kalkreet. Dit is moontlik dat hierdie geochemiese benadering nie so effektief soos fisiese metodes soos swaar mineraal skeidings mag wees nie. Dit is nogtans belangrik om die toepaslikheid van hierdie metodes op tanzanite eksplorasie te toests, as gevolg van die potensiële effektiwiteit en relatiewe logistiese gemak van die metodes. Die essensie van die wetenskaplike metodiek wat in hierdie studie gebruik is, is om die geochemie van die grond, stroom sedimente en kalkreet te vergelyk met die geochemie van die onderliggende geologie wat deur middel van diamant boorwerk vasgestel is. ‘n Positiewe korrelasie sou dan dui op ‘n bedekte tanzaniet afsetting. Grond monsters is van ‘n sloot geneem wat loodreg op die strekking van die tanzaniet gemineraliseerde en ongemineraliseerde horisonne gegrawe is. XRF spoor element data van die gronde is vergelyk met die chemie van die onderliggende gesteentes. IGP-AE data wat bekom is deur die monsters met 1 molaar HCl te loog (12 uur loging) is vergelyk met XRF data van dieselfde monsters deur middel van ‘n massa balans indeks om te bepaal of daar enige hidromorfiese dispersie van sekere spoor elemente is en om die toepaslikheid van loging as ‘n alternatief tot die heel-rots metode te bepaal. In die algemeen is daar ‘n goeie korrelasie tussen die grond en rots spoor element data profiele oor die lengte van die seksie. Alhoewel, Ti- en Zr-genormaliseerde massa balans data profiele wys dat daar ‘n mate van afwaartse beweging van grond na die voet van die heuwel is, maar dat hierdie ‘n breuk in die algemene patroon vorm nie. Die IGP-AE data dui daarop dat die hidromorfiese verspreiding van spoor elemente laag is en dat die spoor elemente wat van belang is (V, Cr, Ni en Cu) in nie-oplosbare fases gesetel is. Gevolglik is die logings metode nie ‘n toepaslike alternatief tot die heel-rots XRF metode op gronde nie. XRF analises op die gronde het gewys dat die XRF metode moontlik nuttig kan wees om nuwe areas van tanzanite mineralisasie aan te dui, omdat die gronde wat ‘n grafietiese kalk-silikaat skis oorlê, wat altyd langs die tanzaniet draende horisonne voorkom, is op grond van anomale konsentrasies van V geïdentifiseer. ‘n Eksplorasie konsessie is op die basis van die teenwoordigheid van groot strome, ‘n paar tsavoriet myne wat aanduidend is van hoë prospektiwiteit vir tanzaniet is en as gevolg van ‘n variasie in geologie in die area vir stroom sediment monstering gekies. Tanzaniet en tsavoriet is kogeneties in bekende tanzaniet afsettings. In hierdie geval was die doel om te ondersoek of tanzanietagtige anomalieë (nl. die anomale konsentrasies van V wat in die ondersoek van die grond chemie opgemerk is) in die omgewing van die tsavoriet myne geïdentifiseer kan word. Tsavoriet, die edelsteen variëteit van grossulaar granaat, bevat hoë konsentrasies V. Die monsters is deur middel van die XRF heel-rots metode vir spoor elemente geanaliseer. Die data dui op ‘n paar monsters met hoë V konsentrasies in die ondersoek area. Hierdie studie het ook gedui op ‘n lae stroom sediment verspreiding van die spoor elemente van belang, heel waarskynlik is dit ‘n funksie van die semi-ariede klimaat. Die fyn fraksie (< 90μm) blyk tot ‘n groter mate as die growwer (90μm tot 180μm en 180μm - 300μm) fraksies gemobiliseer te word. Soos voorspel kan word deur die loogings analise het faktor analise gewys dat die spoor elemente deur swaar mineraal geochemie gedomineer word en dat ‘n studie op swaar minerale moontlik ‘n goedkoper en meer toepaslike eksploraise metode is as die wat in hierdie studie ondersoek is. Kalkreet monsters is van ‘n ongebruikte, 10m diep myn skag wat deur die kalkreet gesink is om by die tanzaniet gemineraliseerde horison uit te kom geneem. Monsters is van die bodem van die skag, naaste aan die tanzaniet mineralisasie, tot die oppervlak geneem om die assosiasie tussen die spoor element geochemie en afstand van die tanzaniet mineralisasie te ondersoek. Geen vertikale assosiasie tussen spoor element geochemie en die nabyheid tot die tanzaniet afsetting kon vasgestel word nie. Daar was geen duidelike aanduiding in die geochemie van die kalkreet op die onderliggende tanzanite afsetting nie. Hierdie is ‘n verdere annduiding op die nie-mobiele toestand van spoor elemente in hierdie omgewing. Hierdie studie het suksesvol gedemonstreer dat goed gedefinieerde grond en stroom sediment geochemiese studies moontlik in geochemiese eksplorasie vir tanzaniet bruikbaar kan wees. Dit is belangrik om in gedagte te hou dat dit slegs die geval is as die geochemie van die litologiese paket wat met die mineralisasie geassosieer is uniek en goed bekend is.
11
Zhang, X. (Xiping). "Geochemical exploration for polymetallic ores in volcano-sedimentary rocks:studies in China and Finland." Doctoral thesis, University of Oulu, 2000. http://urn.fi/urn:isbn:9514257871.
Повний текст джерелаАнотація:
Abstract
A comparison between the two very important sulfide belts Raahe-Ladoga Ore
Zone
(RLZ) in Finland and Southern Edge of Altay (SEA) in China, including geological
setting, metallogenic characters and geochemical exploration has been made.
The two sulfide belts share similarities but differ from each other in the
tectonic setting and metallogenic epoch. Polymetallic ores in RLZ and SEA are
the products of the submarine volcanism, but mainly Zn-Cu type is present in RLZ
and Pb-Zn, Cu-Pb-Zn and Cu-Zn types occur in SEA. A main Ni-Cu ore belt related
to the mafic-ultramafic intrusions is also present in the RLZ. RLZ is
metamorphosed to a higher grade than SEA.
The Viholanniemi Zn-Au deposit is a veinlet-disseminated type, possibly
beneath
the stratabound sulphide ores, and the Keketale Pb-Zn deposit is a stratabound
sulphide ore hosted by sedimentary rocks in the volcano-sedimentary formation.
They show many differences. It is suggested that stratabound sulphide ores
overlie stratigraphically the Viholanniemi stringer ores and Au-bearing
stringers underlie the Keketale stratabound ores. Geochemical explorations of
the two deposits exhibit different methods, subjects and procedures. Boulder
tracing and till geochemical exploration proved to be very effective in finding
the Viholanniemi deposit while stream sediment and soil geochemical surveys were
the major and effective tools in finding the Keketale deposit.
An extensional environment and the intensity of volcanism are the essential
conditions for the formation of polymetallic ores related to the volcanism. It
is feasible to classify the ores into the ores hosted by volcanics and
sedimentary rocks in a volcano-sedimentary formation. The stratigraphical
thickness of volcanic rocks and the amount of agglomerates are the two most
crucial factors needed to be considered in prospecting. The chemical variations
of the host rocks can indicate the sulphide ores hosted by sedimentary rocks in
some circumstances.
12
Clarke, Christopher Angus Leo. "A Geochemical Exploration of the Sagehen Volcanic Centre, Truckee-Tahoe Region, California, U.S.A." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/22899.
Повний текст джерелаАнотація:
The assemblage of ca. 6–4 Ma volcanic rocks exposed at the Sagehen Research station in the Truckee-Tahoe region of the northern Sierra Nevada, United States, is interpreted to be, within the Ancestral Cascades volcanic arc, a Lassen-type stratovolcano complex. Sagehen is of particular importance because it is one of the few Tertiary arc volcanic centres in California which has not been heavily glaciated during the Pleistocene. The volcanic rocks are variably porphyritic or aphanitic, including abundant plagioclase with clinopyroxene and amphibole. The rocks range from basalt to basaltic-andesite to andesite in composition. Basalts are olivineand clinopyroxene-bearing with minor phenocrysts of plagioclase. The basaltic-andesites are primarily pyroxene bearing while the andesites contain pyroxene-, plagioclase- and hornblende porphyritic phases. Sagehen arc lavas are calc-alkaline and enriched in the large ion lithophile elements and depleted in High Field Strength Elements. The basalts are depleted in Zr and Hf while the andesites are enriched with Zr and Hf relative to the middle rare earth elements. Compared to previously studied Ancestral Cascade arc samples, Sagehen region basalts have lower 143Nd/144Nd isotopic values that do not correspond to proposed mantle-lithosphere mixing lines, while the andesite samples appear to represent the interplay of these two components on a 87Sr/86Sr vs. 143Nd/144Nd. The trace element data and isotopic plots suggest that the melts that produced the basalts are from subduction modified mantle wedge peridotites that ponded near the base of the lithosphere similar to the generation of other subduction related calc-alkaline lavas along convergent continental margins. The andesitic samples appear to be the result of further modification through crustal assimilation as seen in the higher isotopic Sr contents in the andesites and Ce/Smpmn vs. Tb/Ybpmn plots. Finally, the proposed map units from Sylvester & Raines (2007) were found to contain various geochemical facies based on the samples collected indicating that some map units may have to be redefined or sub-divided.
13
Cox, David. "Surficial and geochemical evolution of periglacial soils : applications to mineral exploration in Yukon." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44758.
Повний текст джерелаАнотація:
Exploration geochemistry is a powerful tool when exploring for gold deposits in periglacial environments, such as west-central Yukon. However, this study identified two main challenges to using soils as indicators of bedrock mineralization: 1) the variability of sample material over the scale of hundreds of meters and 2) The dilution of metal concentration in soil caused by the addition of loess. Herein, a study into the distribution of surficial materials is presented, the outcome of which is the mapping of surficial units whereby the terrain is divided into domains based on topography, surficial material and surficial processes. Furthermore, a study into the distribution of metals, specifically gold, within a selection of domains concludes that there is considerable geochemical variation between domains and that no single optimum sample material occurs throughout west-central Yukon. Hence, a tailored sampling protocol, based on surficial mapping is recommended.
Results of scoping studies to the development of two methods to aid in exploration for gold deposits in west-central Yukon are presented: 1) a method for approximating the proportions of loess in a soil sample; proportion of loess in the Bdm horizon and Bm horizon from a selection of exposures from the Golden Saddle deposit were calculated. 2) A method for detecting bedrock alteration by the analysis of the mineralogy of surficial material; Well-crystalized illite, which forms specifically under hydrothermal conditions is identified in surficial material overlying the Golden Saddle deposit. This demonstrates that bedrock alteration minerals remain stable under surficial conditions. The two methods outlined above are demonstrated to be plausible and applicable to exploration in this area.
14
Booden, Mathijs Adriaan. "Geochemical development of the late Cenozoic arc volcanism in Northland and the Coromandel, and implications for geochemical exploration in the Hauraki goldfield." Thesis, University of Auckland, 2011. http://hdl.handle.net/2292/8971.
Повний текст джерелаАнотація:
Late Cenozoic subduction-related volcanism in northern New Zealand left a record in Northland, the Coromandel and, from 2 Ma, in the central North Island. Over 90% of the volcanic succession formed prior to the intensely studied central North Island volcanism. This study documents geochemical and isotopic characteristics of volcanic rocks of the Northland Arc and the Coromandel Volcanic Zone (CVZ). Rocks are basaltic, andesitic, dacitic to rhyolitic, with subordinate trachybasalts to trachydacites. All samples have an arc-type trace element signature, Northland Arc (23.5-15.5 Ma) western belt rocks are relatively mafic, and eastern belt rocks relatively felsic. The contrast possibly reflects variable crustal thickness across the Northland peninsula, with eastern belt magmas the products of more deep-seated magmatic systems. The CZV (18-1.95 Ma) erupted comparable andesites to Northland Arc eastern belt rocks, and also basalts, rhyolites and high-magnesium andesites. CVZ basalts resemble least differentiated andesites, but have relatively high Na2O and TiO2. CVZ rhyolites have distinct compositions, where the least differentiated rhyolites may represent partial melts derived from equivalents to CVZ basalts. Crystal and groundmass compositions suggest that andesites are mixtures of mafic and silicic components that to some extent resemble the compositions of CVZ basalts and rhyolites, respectively. With the recognition of high-magnesium andesites in the Kiwitahi chain, the CVZ includes all the major rock types that characterise the modern volcanic system. Hydrothermally altered CVZ andesites host c. 50 epithermal gold-silver deposits of the Hauraki goldfield. Trace elements used in exploration to locate such ore bodies are mostly confined to veins, so the range of geochemical exploration targeting can potentially be extended by a better understanding of major element mass changes that occur over larger distances. The unaltered rock dataset obtained in this study provides a baseline to quantify major element mass changes in altered rocks by using the immobile element ratio Zr/Ti to estimate protolith composition. A test case in the Waitekauri area alteration zone shows that maximum and average K and Rb gains consistently increase from periphery to core over a 3 km wide section, demonstrating that quantitative mass balance data can be a significant addition to geochemical exploration.
15
Ghavami-Riabi, Reza. "Geochemical exploration for base metal sulphide deposits in an arid environment (eastern Namaqua Metamorphic Province), South Africa." Thesis, Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-06192007-100552.
Повний текст джерела
16
Polito, Paul A. "Exploration implications predicted by the distribution of carbon-oxygen-hydrogen gases above and within the Junction gold deposit, Kambalda, Western Australia /." Title page, table of contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09PH/09php769.pdf.
Повний текст джерела
17
Zhang, Xiping. "Geochemical exploration for polymetallic ores in volcano-sedimentary Rocks : studies in China and Finland /." Oulu : Oulun Yliopisto, 2000. http://herkules.oulu.fi/isbn9514257871.
Повний текст джерела
18
Coward, R. N. "A statistical appraisal of regional geochemical data from the Southwest Pacific for mineral exploration." Thesis, Imperial College London, 1986. http://hdl.handle.net/10044/1/37979.
Повний текст джерела
19
Hamisi, Jonathan. "Defining The Geochemical Footprint For Gold Mineralisation Around Birthday Reef.Reefton Goldfield, New Zealand." Thesis, Stockholms universitet, Institutionen för geologiska vetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-132115.
Повний текст джерелаАнотація:
Abstract Orogenic gold deposits from the Reefton goldfield in New Zealand hosted in Ordovician metasediments of the Greenland group have produce 67 tons of gold before 1951. The Blackwater mine in Waiuta account for about 1/3 of the gold production at Reefton prior 1951. The ore system at Blackwater consist of NE trending steeply dipping gold-bearing quartz veins (Birthday reef) occurring in faulted, sheared and folded alternating sequence of sandstone-mudstone metamorphosed to low greenschist facies and hydrothermally altered proximal to distal from the quartz vein. Host rock and ore forming fluids interaction resulted in a systematic change in the mineralogy and geochemistry of the wallrock developing a distinctive footprint of the ore system. The mineral assemblage subsequent to hydrothermal alteration is formed by quartz veining, chlorite, carbonates (minor calcite-dolomite-ankerite-siderite), albite, K-Mica and composite quartz-carbonate veining, carbonates spotting, pyrite, arsenopyrite, chalcopyrite, cobaltite, galena and in a lesser extent ullmannite, gersdorffite, pentlandite, millerite and sphalerite. Mass balance calculation based on geochemical data obtained by ultra-low detection analysis with a detection limit in part per trillion of Au, As and Sb provide new insight in the geochemical footprint of the ore system at Blackwater. A clear zone of roughly 40 meters (20 meters above and below the birthday reef) is enriched in Au, As and Sb up to respectively 6806%, 605% and 891% compared to the un-mineralised protolith. Furthermore, mass changes in K2O and Na2O indicate a consistent decrease in Na and increase in K in the vicinity of the Birthday reef reflecting the replacement of albite by K-mica. This is corroborated by pattern of alkali alteration index Na/Al for albite and 3K/Al for K-Mica showing similar trend. Carbonation and de/-hydration index also exhibits peaks in samples adjacent to the Birthday reef, though carbonation index is also influenced by carbonates content in the protolith or late carbonation that may not related to gold mineralisation. Using the indicators above-mentioned it is possible to define the mineralogical and geochemical “footprint” for the ore system in the host rock allowing to use this footprint as a tool for mineral exploration for orogenic gold deposits similar to Blackwater. Given that the geochemical footprint of orogenic gold deposit such as Blackwater is significantly wider than the economically viable part of the deposit defining the footprint of the ore system offers the potential for vectoring from sub-economic mineralisation towards higher-grade ore that is economically viable.
20
Yang, Jin. "Exploration geochemical mapping in the north-eastern sector of the Morokweng impact structure, South Africa." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8373_1189147095.
Повний текст джерелаАнотація:
The Morokweng impact structure which is located in the North West province of South Africa, has attracted attention as a potential host for Ni-PGE mineralization. Geochemical exploration techniques using hydroxylamine partial extraction were used to determine the nature and source of surface geochemical anomalies known to occur in the overlying aeolian sang regolith. About 40 aeolian samples were taken from an area of about 35 square kilometer, located in the north eastern sector of the Morokweng impact structure. The samples were sieved to various grain size fractions and partially extracted using varying concentration of hydroxylamine hydrochloride at 50°
C.
21
Held, Sebastian [Verfasser], and T. [Akademischer Betreuer] Kohl. "Joint exploration of geothermal systems using geophysical and geochemical techniques / Sebastian Held ; Betreuer: T. Kohl." Karlsruhe : KIT-Bibliothek, 2018. http://d-nb.info/1164081195/34.
Повний текст джерела
22
Harris, Jeff R. "Processing and integration of geochemical data for mineral exploration: Application of statistics, geostatistics and GIS technology." Thesis, University of Ottawa (Canada), 2002. http://hdl.handle.net/10393/6421.
Повний текст джерелаАнотація:
Geographic Information Systems (GIS) used in concert with statistical and geostatistical software provide the geologist with a powerful tool for processing, visualizing and analysing geoscience data for mineral exploration applications. This thesis focuses on different methods for analysing, visualizing and integrating geochemical data sampled from various media (rock, till, soil, humus), with other types of geoscience data. Different methods for defining geochemical anomalies and separating geochemical anomalies due to mineralization from other lithologic or surficial factors (i.e. true from false anomalies) are investigated. With respect to lithogeochemical data, this includes methods to distinguish between altered and un-altered samples, methods (normalization) for identifying lithologic from mineralization effects, and various statistical and visual methods for identifying anomalous geochemical concentrations from background. With respect to surficial geochemical data, methods for identifying bedrock signatures, and scavenging effects are presented. In addition, a new algorithm, the dispersal train identification algorithm (DTIA), is presented which broadly helps to identify and characterize anisotropies in till data due to glacial dispersion and more specifically identifies potential dispersal trains using a number of statistical parameters. The issue of interpolation of geochemical data is addressed and methods for determining whether geochemical data should or should not be interpolated are presented. New methods for visualizing geochemical data using red-green-blue (RGB) ternary displays are illustrated. Finally data techniques for integrating geochemical data with other geoscience data to produce mineral prospectivity maps are demonstrated. Both data and knowledge-driven GIS modeling methodologies are used (and compared) for producing prospectivity maps. New ways of preparing geochemical data for input to modeling are demonstrated with the aim of getting the most out of your data for mineral exploration purposes. Processing geochemical data by sub-populations, either by geographic unit (i.e., lithology) or by geochemical classification and alteration style was useful for better identification of geochemical anomalies, with respect to background, and for assessing varying alteration styles. Normal probability plots of geochemical concentrations based on spatial (lithologic) divisions and Principal Component Analysis (PCA) were found to be particularly useful for identifying geochemical anomalies and for identifying associations between major oxide elements that in turn reflect different alteration styles. (Abstract shortened by UMI.)
23
FERRETTI, Giacomo. "The application of natural and NH4+-enriched chabazite zeolites as soil amendment: a bio-geochemical exploration." Doctoral thesis, Università degli studi di Ferrara, 2017. http://hdl.handle.net/11392/2488289.
Повний текст джерелаАнотація:
Little is known about natural and NH4+-enriched zeolite amendment effects on soil N pool dynamics, N gaseous emissions and soil microbial biomass. In this thesis, the attention is focused on gaining new insights about these subjects by the mean of both long-term field investigations and short-term laboratory tests. In first instance, N and C pools dynamics and 15N distribution in an agricultural soil amended with both natural (5 and 15 kg m-2) and NH4+-enriched (7 kg m-2) zeolites have been investigated. Zeolite amendments increased soil cation exchange capacity in the bulk soil and affected soil microbial biomass. The NH4+ supplied with NH4+-enriched zeolites was probably immediately accessible to soil microbial biomass causing a higher N immobilization and a lower microbial C/N ratio. On the other hand, amendments with zeolites at natural state probably favoured the development of fungal biomass as testified by the higher microbial C/N ratio. δ15N turnover in the soil-plant system indicated that a significant amount of N derived from NH4+-enriched zeolites remained in the soil until the growing season and that it was subsequently significantly up took by sorghum plants. On the other hand, in soils amended with zeolites at natural state, isotopic results showed that plants tissues were characterized by a 15N approaching that of chemical fertilizers, suggesting an enhanced N uptake from this specific source with respect to the unamended plot.Similar evidences were recorded also during maize and wheat cultivation. The effects of different chabazite zeolite amendments on soil gaseous emissions (CO2, N2O, NOx and NH3) were evaluated in high resolution by the mean of a short-term incubation experiment. Different soil-zeolite mixtures were incubated for 24 h both immediately after the application of urea fertilizer and without a further N input. Immediate CO2, N2O, NOx and especially NH3 emissions after fertilizer application were generally reduced in soils amended with zeolites at natural state, indicating a potential valuable material for reducing soil C-N gaseous losses. On the other hand, the application of NH4+-enriched zeolites supplied a fraction of N that was immediately subjected to gaseous losses.Finally, the short-term effects of different chabazite zeolite amendments on soil microbial biomass (and activity) have been investigated. A silty-clay agricultural soil was amended in three different ways, including the addition of natural (5 and 15 wt%, respectively) and NH4+-enriched (10 wt%) chabazite zeolite rich tuffs. Dissolved organic carbon (C), total dissolved N, NH4+, NO3-, NO2-, microbial biomass C, N and δ15N and ergosterol were periodically measured over a time course of 16 days in a laboratory incubation experiment. Soil amended with 5 wt% of zeolites at natural state showed increased ergosterol content as well as microbial C/N ratio, suggesting that fungal biomass was probably favored.On the other hand, the NH4+-enriched zeolite showed strong interactions with soil microbial biomass N. Isotopic measurements supported microbial assimilation of the N introduced with this material since day 2 of incubation. The high dissolved organic C and microbial N suggested an increase of mineralization and immobilization processes. In addition, microbial N was related to NO3- production over time and inversely related to NH4+, suggesting nitrification processes especially from day 7. Low microbial C/N ratio support bacterial prevalence in this substrate. In conclusion, amendments with zeolites at natural and NH4+-enriched states differently affected soil N pool dynamics, gaseous emissions and microbial biomass. Natural zeolites have probably increased fertilization efficiency, reduced soil gaseous emissions and favored fungal biomass. On the other hand, notwithstanding the N inserted with NH4+-enriched zeolites has been proved to be exploited by plants, this material caused a priming effect on soil microbial biomass.Poco è noto sugli effetti dell’applicazione di zeoliti naturali ed arricchite con NH4+ come ammendanti di suoli agricoli sulle dinamiche dei pool dell’azoto (N), emissioni gassose e sulla biomassa microbica del suolo. In questa tesi, l’attenzione è stata focalizzata sull'acquisizione di indizi riguardo queste tematiche tramite sia esperimenti a lungo termine in campo che esperimenti a breve termine. Innanzitutto, le dinamiche dei pool azotati e del carbonio (C) e la distribuzione del 15N in un suolo agricolo ammendato con zeolite sia allo stato naturale che arricchita con NH4+ sono state investigate. L’ NH4+ introdotto con la zeolite arricchita si è rilevato immediatamente accessibile alla biomassa, causando immobilizzazione di N e un basso C/N. L’addizione di zeoliti allo stato naturale ha favorito lo sviluppo di biomassa fungina come testimoniato dall’elevato C/N. Le dinamiche del δ15N nel sistema suolo-pianta hanno indicato che l’N derivato dalla zeolite arricchita è rimasto nel suolo fino alla stagione di crescita del sorgo ed un suo significativo utilizzo da parte dalle colture. Riguardo ai suoli ammendati con zeoliti naturali, le analisi isotopiche hanno mostrato che i tessuti delle piante erano caratterizzati da un δ15N più simile a quello dei fertilizzanti chimici rispetto ad un suolo non trattato, suggerendo un aumento nell’efficienza della fertilizzazione. Evidenze simili sono state riscontrate anche durante la coltivazione di mais e grano. Gli effetti dell’utilizzo di tali materiali riguardo le emissioni gassose del suolo (CO2, N2O, NOx and NH3) sono stati quantificati in alta risoluzione tramite una breve incubazione. Varie misture di suolo e zeolite sono state incubate per 24 ore sia dopo l’applicazione di urea che senza aggiunta di N. Le emissioni dopo l’applicazione di urea sono state generalmente ridotte nei suoli ammendati con zeoliti allo stato naturale, indicando questo materiale come una valida pratica per ridurre le emissioni di N e C da suoli agricoli. D’altra parte, l’applicazione di zeoliti arricchite in NH4+ ha fornito una frazione di N immediatamente soggetta ad emissioni gassose. Infine gli effetti nel dell’applicazione di zeoliti sulla biomassa microbica del suolo sono stati studiati. Un suolo agricolo è stato ammendato in tre diverse modalità (zeolite naturale 5 e 15 % in peso e arricchita in NH4+ 10 % in peso) ed incubato per 16 giorni misurandone parametri chimico-biologici. Il suolo trattato con 5 % di zeolite naturale ha mostrato un aumento di ergosterolo così come del C/N della biomassa, indici di un probabile sviluppo di biomassa fungina. La zeolite arricchita in NH4+ ha mostrato forti interazioni con l’N della biomassa. Le misurazioni isotopiche hanno supportato l’assimilazione microbica dell’N introdotto con questo materiale fin dal secondo giorno di incubazione. L’elevato C disciolto e l’elevato N della biomassa suggeriscono un aumento di mineralizzazione e immobilizzazione. In aggiunta, l’N della biomassa è relazionato direttamente con la produzione di NO3- nel tempo ed inversamente relazionato alla quantità di NH4+, suggerendo processi di nitrificazione a partire dal giorno 7. Il basso rapporto C/N della biomassa microbica indica una prevalenza batterica nel substrato. In conclusione, l’utilizzo di zeoliti naturali ed arricchite hanno influenzato le dinamiche dei pool azotati, le emissioni gassose e la biomassa microbica del suolo. Le zeoliti allo stato naturale hanno probabilmente aumentato l’efficienza della fertilizzazione, ridotto le emissioni di gas e favorito lo sviluppo di biomassa fungina. D’altra parte, nonostante l’utilizzo da parte delle colture dell’N inserito tramite le zeoliti arricchite sia stato provato, questo materiale ha causato un chiaro effetto di priming sulla biomassa microbica.
24
Drouin, Marc. "Application of Factor Analysis in the Identification of a Geochemical Signature of Buried Kimberlites in Near-surface Groundwaters in the Attawapiskat Area of the James Bay Lowlands of Northern Ontario, Canada." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/22872.
Повний текст джерелаАнотація:
In the James Bay Lowlands of northern Ontario, kimberlite pipes are concealed by peat, thick layers of till, and Tyrell sea sediments. Studies have shown that buried ore bodies produce geochemical signatures in surface media. This thesis explores the geochemistry of near-surface groundwater above concealed kimberlite pipes using factor analysis to determine whether (1) a factor analysis can reveal an underlying structure (factors) in a multivariate groundwater geochemical dataset, and whether (2) those factors are related to the presence of concealed kimberlite. Factor analysis was performed on two datasets of nearsurface groundwater, collected at 0.2 m and 1.1 m below ground surface in peat. Results revealed that (1) there is a significant difference in the behaviour of elements in groundwater near the surface compared to those in deeper groundwater, which is sheltered from the effects of the atmosphere; (2) for both datasets, the first factor is dominated by elements known to be enriched in kimberlite, notably rare earth elements (REE), U, Th, Ti – the composition of factor one is consistent with their derivation from kimberlite in a limestone background where such elements are in very low concentration; (3) high-valence and lowvalence kimberlite indicator elements (KIE) are found separated into distinct factors suggesting that once released from the kimberlite after weathering, KIE are subjected to various geochemical processes to be differentiated as they migrate upward to the surface; and (4) Fe and Mn load on a factor distinct from other metals, suggesting that in this environment Fe-Mn-O-OH is not a significant controller of metal mobility in groundwater. Overall, this research has further highlighted the multivariate nature of geochemical processes in groundwater. Compared with previous work in geochemical exploration where often only univariate or bivariate statistics or single element profiles over concealed ore bodies were used, this thesis has shown that factor analysis, as a multivariate data analysis technique, is a robust exploration tool, able to shed light on relevant geochemical processes hidden within geochemical datasets. This thesis shows that high-valence KIE, notably U,V, Th, Ti and the REE, as a group, are better indicators of the presence of kimberlites than other well-known KIE. Single element concentration profiles such as Ni or Cr (known KIE) show similar anomalies over a concealed kimberlite as a factor score profile for factor one (U, V, Th, Ti, REE, Ni) would; however, it is the peculiar assemblage of elements in factor one that makes it unique to kimberlites, a feature that can be used in future exploration work for concealed kimberlites in similar surficial environments, such as the Siberian wetlands. The results suggest that future geochemical exploration work involving groundwater should focus on the more stable groundwater located below the zone of oxidation, sheltered from the effects of the atmosphere.
25
Power, Michael James. "Geochemical Surface Expression of the Phoenix and Millennium Uranium Deposits, Athabasca Basin, Saskatchewan." Thèse, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30918.
Повний текст джерелаАнотація:
The geochemistry of surface media above two known U deposits were examined to observe any possible dispersion products could be detected from them, and based on these findings, improved geochemical exploration techniques are proposed to reduce cost of finding undiscovered U resources. This study examined the materials overlying the Phoenix deposits, which have indicated resources of approximately 58.2 million lbs U3O8 grading 15 wt% that lie at 400 m depth below surface at the unconformity between the overlying Athabasca sandstones and Paleoproterozoic basement rocks. Aqua regia digestion, ammonium acetate at pH 5 and hydroxylamine leaches revealed U, Pb, Co, Ni, Mo, and W anomalies in humus and U, W and As anomalies in B-horizon soils above the ore zones and the basement location of a deposit-hosting, northeast-trending “WS Hanging Wall” shear zone over a three year period. These metal signatures suggest likely upward transport of metals from the deposits to overlying sandstones, and subsequently into the overlying till and soils.
This study also looked at materials above the Millennium U deposit, which has indicated resources of 68.2 million lbs U3O8 grading 4 wt% at ~750 m depth that occurs along a major fault in granites & metamorphosed pelites of Paleoproterozoic age below the Athabasca sandstones. Soil samples taken over the surface projections of an ore-hosting fault and the ore zone yielded anomalous values in U, Ni, Cu and Pb in aqua regia digestion of humus and U, Cu and Pb values in ammonium acetate leach of pH 5 of B-horizon soils. Hydroxylamine leach did not yield as many anomalies as ammonium acetate leach. Measured 4He/36Ar ratios of gas dissolved in water-filled drill holes were observed to be up to about 700 times the atmosphere value for air-saturated water, revealing the presence of radiogenic 4He that was likely produced from decaying U and released in the groundwater above the deposit. Our results suggest upward migration of metals to surface through porous sandstone and fault systems at Phoenix, and upward migration of metals along faults and He gas at Millennium. Both studies indicate the importance of the traverse method of sampling over targets perpendicular to the last major ice-flow event to discern U deposits that are defined by other means.
26
Held, Sebastian [Verfasser], and T. [Akademischer Betreuer] Kohl. "Exploration of Villarrica Geothermal System using Geophysical and Geochemical Techniques [Finale Version] / Sebastian Held ; Betreuer: T. Kohl." Karlsruhe : KIT-Bibliothek, 2018. http://d-nb.info/1165143151/34.
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27
Ledwaba, Lebogang John. "An overview of energy minerals in the Springbok Flatsbasin, South Africa : implications for geochemical and geophysical exploration." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1019880.
Повний текст джерелаАнотація:
This study is informed by the rising demand for power needs in South Africa and aims at understanding the geophysical and geochemical characteristics of the energy minerals in the Springbok Flats Basin and relating them to the prevailing geological and structural setting for improved exploration targeting. The Springbok Flats Basin is part of the Karoo sediments and host to uranium, coal and coal bed methane (CBM) resources. The lithology sections in the basin indicate presence of basaltic lavas at the top, underlain by mudrocks, siltstones, sandstones, conglomerates and diamictite, with interbedded coal beds occasionally. The coals are uraniferous and shale bounded and of lower Beaufort age at 250 Ma. The regional radiometric data identifies the regional extent of the Springbok Flats Basin as a basin with low total count values. This information is useful in exploration as it gives an idea of the limits of the area where to focus application for prospecting licenses. The reduced to pole of the total magnetic field, residuals and first vertical derivative maps clearly show the high magnetic susceptibility nature of the surrounding Bushveld rocks as compared to the low Karoo sediment susceptibility within the basin. There are distinct ring shaped picks within the basin possibly due to known Karoo dolerite sills in particular to the central south western part of the grid. The regional geochemical mapping program is a cost-effective way of providing an overview of the relative abundance levels, regional trends and anomalous patterns in the underlying lithological units. Background values of elements in soils over different lithological units and the identification of anomalous values relative to these elements can easily be identified. The geochemical results show an excellent correlation between soil chemistry and underlying geological formations. A few distinct gravity highs are clearly shown within the basin. Assuming the effect of the Letaba basalt to the gravity readings is uniform across the basin; these distinct anomalies could be due to Karoo dolerite sills as they coincide with areas of distinct high magnetic signature. A conceptual model was generated assuming that the Karoo sediments’ layering is uniform across the gravity profile but changes in the residual are due to an increased thickness of the sill supported by the gentle changes on the surface topography. Satellite imagery has got its challenges especially in areas of vegetation but it does provide a very useful tool in exploration. A number of spectral analysis techniques and band rations can be used to differentiate the areas underlain by the Letaba basalts, the Karoo sandstones/shale and Bushveld granites for mapping purposes. The priority focus will be on the shallower Karoo sediments because of the potential for cheaper mining. Exploration targeting needs to be guided by observed geochemical and geophysical characteristics in order to prioritize areas taking into account the presence of Karoo intrusives such as the dolerite sills that tend to devolatize the coal hence affecting the quality/rank. Structures and gravity signatures are very important in delineating areas with thick sediments that have a potential for CBM. The same understanding in targeting goes a long way in planning drill holes, resource modelling and pre-feasibility stages for mine planning. A high resolution airborne geophysical survey is recommended over the basin to better resolve structures. Geophysical borehole logging is recommended to be part of the exploration drilling programs in the Springbok Flats Basin in order to define the in-situ geophysical characteristics. Geophysical logging is useful in particular for the uranium reserves that cannot be delineated from the surface due to deep intersection.
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Ma, Yamin. "Vegetation as a biotic driver for the formation of soil geochemical anomalies for mineral exploration of covered terranes." University of Western Australia. School of Earth and Geographical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0235.
Повний текст джерелаАнотація:
[Tuncated abstract] Soil is a relatively low cost and robust geochemical sampling medium and is an essential part of most mineral exploration programs. In areas of covered terrain, however, soils are less reliable as a sampling medium because they do not always develop the geochemical signature of the buried mineralisation; possibly a result of limited upward transport of ore related elements into the surficial overburden. As economic demands on the resources industry grow, mineral exploration continues to expand further into areas of covered terrain where the rewards of finding a new deposit relative to the risks of finding it may be comparatively low. Thus, improving the costeffectiveness of a geochemical exploration program requires a sound understanding of the mechanisms by which soil geochemical anomalies form in transported overburden. This thesis examines the deep biotic uplift of ore related elements by deep rooting vegetation as a mechanism for the development of soil geochemical anomalies within transported overburdens, in semi-arid and arid regions. '...' Vegetation and soils were analysed at two Au prospects in Western Australia: Berkley, Coolgardie and Torquata, 210 km south-east of Kambalda, in semi-arid Western Australia to complement both the mass balance and the differential modelling. At Berkley, both the vegetation and soils located directly over the mineralisation showed high concentrations of Au. There may be indirect evidence for the operation of the deep plant uptake flux taking effect from the field evidence at Berkley. Firstly, anomalous concentrations of Au were found in the surface soils, with no detectable Au in the transported overburden. Secondly, the trace element concentrations in vegetation showed correlation to the buried lithology, which to our knowledge has not been reported elsewhere. The results from the samples at Torquata, in contrast, were less conclusive because the Au is almost exclusively associated with a surficial calcrete horizon (at <5 m soil depth). Strong correlations of Ca and Au in leaf samples however, suggest that the vegetation may be involved in the formation of calcrete and the subsequent association of Au with the calcrete. Among the vegetation components, the litter and leaf samples gave the greatest anomaly contrast at both prospects. Finally, three main drivers for the deep biotic uplift of elements were identified based on the results from the mechanistic numerical modelling exercise: i) the deep uptake flux; ii) the maximum plant concentration and; iii) the erosional flux. The relative sizes of these three factors control the rates of formation and decay, and trace element concentrations, of the soil anomaly. The main implication for the use of soils as exploration media in covered terranes is that soil geochemical anomalies may only be transient geological features, forming and dispersing as a result of the relative sizes of the accumulative and loss fluxes. The thesis culminates in the development of the first quantitative, mechanistic model of trace element accumulation in soils by deep biotic uplift.
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Ali, Liaqat. "Gold and base metal exploration studies based on mineralogical and geochemical characterisation of stream sediments from north Pakistan." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3290.
Повний текст джерелаАнотація:
North Pakistan represents a highly favourable area for a variety of mineral deposit types, including arc-related porphyry Cu, Au and Mo and arc and backarc epithermal precious metal deposits (Sweatman et al., 1995; PMDC, 2001). However, few deposits have been discovered in the area, mainly due to its remote nature and inaccessibility, and because of a lack of exploration tools for high altitude terrains. From stream sediment sampling campaigns by local and international organizations, including a large dataset provided by the Pakistan Mineral Development Corporation (PMDC), a significant amount of geochemical data now exists for the region. This data has been incorporated into an Arc-GIS 9.2 database, along with stream catchment and geological information, and detail of all known areas of mineralisation. From this, spatial catchment maps together with multi-element geochemical associations have been studied to delineate areas showing anomalous values for Au and base metals. The two most prospective areas were found to be the Shyok Suture Zone and northern Kohistan, with the dominant control on mineralisation being structural rather than lithological. These areas were targeted for detailed stream sediment sampling and mineralogical and geochemical analysis. From studies of Au and Au pathfinder elements in different size fractions of the stream sediments and heavy mineral concentrates (HMC), the catchments of Teru, Asheriat and Pakora (in order of decreasing rank) were identified as most prospective. Morphological and geochemical analyses of native Au grains from panned concentrates has given an indication of proximity to bedrock source (<10 km) and the possible styles of mineralisation in these catchments; porphyry Cu-type in Asheriat and Pb-Sb quartz veins in Teru and Pakora. Automated mineralogical analysis of the stream sediments (<180 µm fraction) and HMC (<180 µm), using a QEMSCANÒ system, confirmed this interpretation. The effectiveness of the developed methodologies for exploration in remote and high altitude terrains of North Pakistan is discussed, and recommendations made for future exploration.
30
Dunbar, Alyssa C. "Using Surficial Geochemical Methods to Detect Anomalies of Ore Indicator Metals in a Peat Bog at McIlvenna Bay, Saskatchewan, Canada, as a Method for Blind VMS Deposit Exploration." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35833.
Повний текст джерелаАнотація:
Surficial geochemistry, particularly selective leach technology, has proven effective in revealing anomalous concentrations of ore indicator metals overlying zones of buried mineralization. This study focuses on the buried Zn-Cu-Au-Ag VMS deposit at McIlvenna Bay in the Flin Flon Greenstone Belt to determine whether the peat swamp at the surface contains any anomalies of ore indicator metals using simple surficial geochemical techniques. Three selective leaches were performed, ammonium acetate pH 5.0, hydroxylamine, and sodium pyrophosphate. The hydroxylamine leach, which selects for metals in the reducible phase often associated with Mn and Fe oxides, has the clearest anomaly for multiple metals observed simultaneously, at the greatest magnitude. The pyrophosphate leach, which selects for metals that are oxidizable, often associated with organics showed a clear anomaly only for Cu, despite the abundance of organic matter and its great affinity for binding metals, likely because the organic-metal complexes formed in this system are easily exchangeable and highly soluble, not allowing for the formation of clear anomalies. The use of selective leach technology on surficial soil or peat has shown to be effective for delineating ore indicator metal anomalies, giving surface projections of buried mineralization in various types of systems, as long as the dynamics of the system are well understood in order to determine the phase the metals are associated with.
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Mapukule, Livhuwani Ernest. "Interpretation of regional geochemical data as an aid to exploration target generation in the North West Province South Africa." Thesis, University of Fort Hare, 2009. http://hdl.handle.net/10353/268.
Повний текст джерелаАнотація:
This study involves the application, interpretation and utilization of regional geochemical data for target generation in the North West Province, South Africa. A regional soil geochemical survey programme has been carried out by the Council of Geoscience South Africa since 1973. A number of 1:250 000 sheet areas have been completed, but there are no interpretative maps which could aid in mineral exploration and other purposes. In order to utilize the valuable and expensive data, the project was motivated through data acquisition and interpretation to generate exploration targets. The study area is confined to Mafikeng, Vryburg, Kuruman and Christiana in the Northwest Province, where potential exploration and mining opportunities exist in areas of great geological interest. These include geological events such as the Bushveld Complex, the Kalahari manganese field and the Kraaipan greenstone belts. The aim of this project was to utilize geochemical data together with geophysical and geological information to verify and identification of possible obscured ore bodies or zones of mineralization, and to generate targets. Another objective was the author to be trained in the techniques of geochemical data processing, interpretation and integration of techniques such as geophysics, in the understanding of the geology and economic geology of the areas. Approximately 5 kg of surface soil was collected per 1 km2 by CGS from foot traversing. Pellets of the samples were prepared and analyzed for TiO2, MnO and Fe2O3, Sc, V, Cr, Ni, Co, Cu, Zn, As, Y, Ba, Nb, Rb, Th, W, Zr, Pb, Sr and U using the simultaneous wavelengthdispersive X-ray fluorescence spectrometer technique at the Council for Geoscience, South Africa. For each element the mean +2 standard deviations were used as a threshold value to separate the negative from the positive anomalies. The integration of geological, geophysical and geochemical information was used to analyze and understand the areas of interest. A number of computer programmes were extensively used for data processing, manipulation, and presentation. These include Golden Software Surfer 8®, Arc-View 3.2a®, TNT-Mips®, JMP 8 ®, and Microsoft Excel®. Through geochemical data processing and interpretation, together with the low resolution aeromagnetic data, gravity data and geological data, seven (7) exploration target areas have been generated: These have been numbered A to G. It is concluded that there is good potential for Cr, PGMs, vanadium, nickel, iron, copper, manganese, uranium and niobium in the targets generated. The results provide some indication and guide for exploration in the target areas. In Target A, Cu, Cr, Fe, Ni and V anomalies from the lower chromitite zone of far western zone of the Bushveld Complex, which has be overlain buy the thick surface sand of the Gordonia Formation. Target B occurs over the diabase, norite, andesitic lava and andalusite muscovite hornfels of the Magaliesberg Formation. This target has the potential for Cu, Fe and Ni mineralization. The felsic rocks of the Kanye Formation and the Gaborone Granite in target C have shown some positive anomalies of niobium, uranium, yttrium and rubidium which give the area potential for Nb, REE and U exploration. Target D is located on the Allanridge Formation, and has significant potential for Ni-Cu mineralization, and is associated with the komatiitic lava at the base of the Allanridge Formation in the Christiana Area. The light green tholeiitic, calc-alkali basalt and andesitic rocks of the Rietgat Formation are characterized by a north-south trending yttrium anomaly with supporting Ba and Y anomalies (Target E). This makes the area a potential target for rare earth elements. Calcrete on the west of the Kuruman has a low b potential target for vanadium. It is believed that the area might be potential for potassium-uranium vanadate minerals, carnotite which is mostly found in calcrete deposits. This study has proved to be a useful and approach in utilizing the valuable geochemical data for exploration and future mining, generated by Council for Geoscience Science. It is recommended that further detailed soil, rock and geochemical surveys and ultimately diamond drilling be carried out in the exploration target areas generated by this study.
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Katombe-Kisumbule, Paul. "Geochemical exploration for copper - cobalt in the Democratic Republic of Congo, Central African Copperbelt: a case study on PR851." Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/3035.
Повний текст джерелаАнотація:
The PR851 licence area is located at about 80 km west from the town of Likasi in the district of Haut-Katanga and 175 km north-west of Lubumbashi, the capital city of Katanga Province in the Democratic Republic of Congo. The exploration licence was granted by the government of the Democratic Republic of Congo to First Quantum Minerals Ltd through its Congolese subsidiary Compagnie Minière de Sakania Sprl (CoMiSa Sprl) under certificate N˚ CAMI/CR/70/2003 on the 10th of October 2003 for a period of 5 years with a possibility of renewal for 3 years in respect to the new Congolese mining code. The PR851 area lies on fragments of Mines Subgroup rocks of the Roan Group in the Congolese Copperbelt where most of the Cu-Co and stratiform-stratabound deposits such as Kipushi, Ruashi-Etoile, Kinsevere, Kipoi, Luishya, Luswishi, Shituru, Kamoya, Kambove, Tenke- Fungurume, Shinkolobwe, Swambo, Mindingi and Kamoto among others are found. During the 20th century, the Union Minière du Haut Katanga (U.M.H.K.) undertook mineral exploration in the Congolese Copperbelt and numerous copper- and cobalt-occurrences were identified (for instance Kibamba copper occurrence in PR851 area). From 2003, the Compagnie Minière de Sakania Sprl initiated a grassroots exploration program in PR851 area and geochemical exploration survey as one of the mineral exploration tools was implemented to aim at detecting copper and cobalt concentration in soil. The B horizon of the thick tropical soil in the area was sampled and soil samples were sent to Genalysis laboratories in Johannesburg, Republic of South Africa for main chemical analysis of Cu and Co only, whereas 10% of analyzed samples were dispatched to Perth, Western Australia for quality control analysis. Thresholds for anomalies of copper and cobalt were defined by literature comparison, standard deviations and spatial analysis. The anomalies were tested at a later stage by reverse circulation / diamond drilling during the year of 2005 to 2008 and the Cu-Co resources were estimated by Digital Mining Services of Harare, Zimbabwe in the year of 2008. Geological logging of chips from reverse circulation and diamond drill cores revealed that copper mineralization is represented by malachite, chrysocolla, chalcopyrite and bornite whereas cobalt mineralization appeared in form of heterogenite. The source of supergene mineralization remains unknown. Recommendations have been made to undertake more geological exploration work in order to fully investigate the geological setting and structural architecture of the region, which may result in a better understanding of the Cu-Co mineralization system and ore genesis. The latter has been no consensus up-to-date and different theories have been proposed to discuss the ore genesis, including syn- and dia- genetic, synorogenic and sulphide remobilization to late-to-post- orogenic Cu-Zn-Pb Kipushi-type deposit. However, geological observations favored that the diagenetic and syngenetic models are applicable to numerous deposits in the Central African Copperbelt.
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Nkomo, Nomagugu. "The nature of geochemical anomalies associated with the PGE mineralization in the Stella layered intrusion, North West province, South Africa." University of the Western Cape, 2020. http://hdl.handle.net/11394/7713.
Повний текст джерелаАнотація:
Masters of ScienceThe redistribution patterns of trace elements related to ore mineralisation in the secondary environment are the foundation of regolith exploration geochemistry. Understanding the controls of these element patterns is important for the detection of underlying ore deposits, especially in areas where bedrock is concealed by extensive regolith. The study area, which hosts PGE and gold deposits within the Stella Layered Intrusion is one such area. A major aim of this study was to use major element data to characterise the regolith materials enclosing the PGE mineralisation in the Stella Layered Intrusion to ascertain the degree of weathering that has occurred. Furthermore, the study aimed to relate the weathering patterns in regolith to the distribution of pathfinder elements of PGEs and gold in areas proximal and distal to the mineralised zones. The study was conducted using XRF data, which included major oxide and trace element data. These data were used to characterise regolith materials (scatter plots, K/Al versus Mg/Al plots) and calculating indices that determine the degree of weathering such as CIA and ICV indices as well as A-CN-K and A-CN-FM diagrams. Signatures of pathfinder/ trace elements were enhanced by hydroxylamine hydrochloride partial selective leach technique. The distribution patterns of the partial leach data were compared to the intensity of weathering and weathering products, e.g. manganese oxides, carbonates in areas proximal and distal to the ore zone. In the Serpens North Prospect, the major horizons that were identified include saprolith, stone line and aeolian sands. Incipient calcrete formation occurs in some parts of the Sirius Prospect, while in some parts, well developed, thick calcrete layers are found interlayered with the saprolith and aeolian sand.
34
Wang, Changlin. "Application of Geographical Information Systems to the interpretation of exploration geochemical data and modelling of gold prospects, South Devon, England." Thesis, University of Leicester, 1995. http://hdl.handle.net/2381/34978.
Повний текст джерелаАнотація:
Geographical Information Systems (GIS) are rapidly developing computer systems for managing spatial data. This study used GIS techniques to analyse and visualize exploration geochemical data, to extract spatial information from Landsat images, gravity and aeromagnetic data and to model gold potential using logistic regression, weights of evidence, Dempster-Shafer and fuzzy logic methods. Regional exploration geochemical data from various data sets were represented using the catchment method. Experimental regression analyses for evaluating the influence of Fe-Mn scavenging effect and lithological variations show that zinc is most affected by these factors. The importance of anomalous catchments and dilution effect for zinc was also evaluated using mineralization rating and productivity methods. Soil samples collected in this study suggest that there is no base metal mineralization associated with gold at Whympston area, but limited anomalous haloes around the Loddiswell Mine. Lineaments were extracted from Landsat images using the objective lineament extraction and enhancement method. A shaded relief technique was used to enhance the variations of topographical, gravity and aeromagnetic data. Gravity and aeromagnetic data were also processed using second vertical derivative and reduction to the magnetic pole. Results show structural features possibly related to faults on the processed images and highlight highly elevated magnetic anomalies over the Kingsbridge area suggesting an association with possible unexposed hornblende schist related to the Start Complex. Both descriptive and conceptual models for gold occurrences were constructed, which were then correlated with results from the inductive and deductive modelling methods used. Logistic regression and weights of evidence methods have relatively good correlations with known gold occurrences and highlight the importance of felsite in the area. However, very low weights are related to binary patterns over the areas associated with unexposed gold potentials. Dempster-Shafer and fuzzy logic methods can overcome the shortcomings for incomplete data in data driven methods. These methods allow the inputting of weights (degree of belief and membership grade) from well documented mineral deposit models without any prior knowledge of gold mineralization in the area. The deficiency of deductive methods is that there are sometimes large discrepancies between the predicted favourable areas and known gold occurrences.
35
Diaz-Unzueta, Raul 1957. "GEOCHEMICAL AND ISOTOPIC STUDY OF CALCITE STOCKWORKS AT LA ENCANTADA MINING DISTRICT, COAHUILA, MEXICO: RELATIONSHIPS WITH OREBODIES AND IMPLICATIONS FOR EXPLORATION." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276408.
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Samal, Abani Ranjan. "Genetic and exploration models for the Florida Canyon Au deposit, Nevada : integrating geological, geochemical, GIS, remote sensing, geostatistical and statistical data analysis /." Available to subscribers only, 2007. http://proquest.umi.com/pqdweb?did=1342732471&sid=6&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Повний текст джерела
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Bryson, Stuart Edwin. "A Geochemical Characterization of Streams Surrounding the Tom and Jason SEDEX Deposits of the MacMillan Pass, Yukon, Canada: Implications for Mineral Exploration and Toxicology." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35781.
Повний текст джерелаАнотація:
This study presents a geochemical characterization of stream waters draining the sedimentary exhalative (SEDEX) Tom and Jason Pb-Zn deposits and surroundings in the MacMillan Pass, Yukon. Streams sampled have wide ranging pH values of 3 to 8.2. Dissolved metal concentrations vary widely with water source and pH. Of note, streams draining the Tom and Jason deposits are acidic and neutral respectively, which greatly affects metal solubility. The Tom Deposit drainage is extremely high in dissolved and fine sediment fraction lead, as well as dissolved zinc. Neutral streams draining the Jason deposit have less dramatic metal concentrations, but do show elevated dissolved zinc and fine sediment fraction lead concentrations. Modelling using the thermodynamic equilibrium program PHREEQC and XRD analysis indicate that ferricrete hardpans underlying acidic drainages are formed where drainage water is saturated with respect to schwertmannite. Ferrihydrite is formed where the rapid mixing of waters increases the pH rapidly. An aluminium oxy-hydroxide, likely gibbsite, precipitates where pH levels exceed 4.5, however it appears to dissolve with decreasing pH. This study looks at dissolved, suspended and fine fraction sediments to provide a more complete view of metal movement under various conditions which may be useful to both exploration and environmental fields.
38
Malatji, Tsholofelo S. "Petrological, mineralogical and geochemical studies of Zhongchang and Yantiangou ultramafic intrusions from the Panxi region, Sichuan Province, S-W China. Metallogenic and Exploration implications." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1012951.
Повний текст джерелаАнотація:
The Emeishan Large Igneous Province is one of the largest igneous provinces in the world. It is marked by basaltic extrusives that vary in Ti amount, classified as high Ti and low Ti. Several mafic to ultramafic intrusions occur in the province as well as granitic intrusions. The mafic-ultramafic intrusions are associated with mineralization; large layered utlramafic intrusions bearing Fe-Ti-V mineralization, while small dyke like or sill like intrusions contain Cu-Ni-PGE mineralization. The Zhongchang and Yantiangou mafic- ultramafic intrusions are small such intrusions bearing Ni-Cu-PGE mineralization. The deposits show a lot of similarities in source magma, evolution and mineralization. Parental magma for both deposits show alkaline tendencies, and a high Mg # indicative of primitive magma that underwent little crustal contamination. Mantle range Cu/Pd ratios show parental magma fertile in chalcophile elements and both deposits proceed to show depleted mantle normalized values as a result of sulphide saturation and subsequent mineralization. Mineralization in Zhongchang is hosted at the contact between peridotite and pyroxenite, interstitial to olivine and clinopyroxene. Alteration minerals include epidote and chlorite. High Cu/Pd ratios suggest earlier sulphide saturation and removal of a PGE sulphide, and a second sulphide saturation phase resulted in Ni-Cu mineralization. Mineralization in Yantiangou is hosted in biotite effectively following fractionation of olivine and clinopyroxene after which sulphide saturation occurred, precipitating sulphide minerals in biotite. Pyrite and millerite occur as a result of late stage hydrothermal alteration. Cu/Pd ratios are high indicating prior sulphide saturation occurred where PGE partitioned into sulphides. Ni/MgO ratios observed for both deposits indicate a state of sulphide under saturation where PGE partitioned into tellurides and bismurthinides and Ni into olivine. Average tenors for mineralized units are; Zhongchang at 5%Ni, 9% Cu, 4300ppb Pt and 2000ppb Pd, and Yantiangou having relatively lower tenors at 3.2%Ni, 6.5% Cu, 3000ppb Pt and 1300 ppb Pd.
39
Coish, Diane Wanda. "Applicability of laser ablation and partial dissolution ICP-MS techniques on Mn-Fe-oxide coatings of stream pebbles to mineral exploration and environmental monitoring." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0033/MQ62378.pdf.
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Cook, Stephen John. "The distribution and behaviour of platinum in soils of the Tulameen ultramafic complex, southern British Columbia : applications to geochemical exploration for chromite-associated platinum deposits." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/29803.
Повний текст джерелаАнотація:
Exploration for chromitite-associated Pt deposits is hampered by a poor understanding of the distribution and behaviour of Pt in the surficial environment. This study investigates Pt content, residence sites and PGE mineralogy of soils developed on till and colluvium above the Tulameen ultramafic complex in southern British Columbia.
Seventy-six soil profiles, as well as sediments, bogs and waters were sampled above the dunite core of the Tulameen complex, within which Pt occcurrences consist of massive-to-discontinuous segregations of platinic chromitite. Pt content of the -212 um fraction of soils and sediments was determined by fire assay-inductively coupled plasma spectroscopy. Samples from fourteen selected profiles were then examined in detail to determine Pt mineralogy and its distribution between different size, density and magnetic fractions.
Pt concentrations in the -212 um fraction of C horizon soils range from 2 to 885 ppb and are closely related to soil dunite content, as estimated from MgO content and verified by XRD mineralogy. Dunite colluvium (mean: 24.2% MgO), locally-derived dunitic till (mean: 16.5% MgO) and exotic non-dunitic till (mean: 5.7% MgO) have median Pt concentrations of 88 ppb, 36 ppb and 8 ppb, respectively.
This trend is evident in all size and density fractions. Pt content of heavy mineral (SG > 3.3) fractions is 10-2Ox greater than in light mineral fractions. Pt is most abundant in the heavy magnetic fraction from non-dunitic tills and dunitic tills remote from known mineralization, but the proportion of Pt in the heavy non-magnetic fraction increases with increasing proximity to mineralization.
SEM and microprobe studies of heavy fractions from C horizons identified Pt-Fe-Cu alloys as free grains, and as inclusions in Mg-silicates and chromites. Chromite occurs as Mg-Cr-rich anhedral fragments and as Fe-rich euhedral to subhedral crystals. The latter, relatively more important in the magnetic fraction, are interpreted as Pt-poor grains disseminated throughout the dunite whereas fragments are relatively more important in the non-magnetic fraction and are interpreted as remnants of Pt-bearing massive chromitite segregations. The abundance of chromite fragments in soils near chromitite segregations accounts for the high Pt content of the non-magnetic heavy fractions of these soils.
The -270 mesh fraction or the magnetic heavy fraction of C horizon soils would be the most suitable sample media for reconnaissance geochemical sampling. However, the greater contrast, more limited dispersion and Mg-Cr-rich chromite association of the non-magnetic heavy fraction make it a more suitable media for detailed geochemical sampling.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
41
Andrews, Marcelene. "The use of chemostratigraphy and geochemical vectoring as an exploration tool for platinum group metals in the Platreef, Bushveld Igneous Complex, South Africa : a case study on the Tweefontein and Sandsloot farms." University of the Western Cape, 2015. http://hdl.handle.net/11394/5229.
Повний текст джерелаАнотація:
>Magister Scientiae - MScThe Platreef is known for its complexity and its heterogeneous lithologies, coupled with an unpredictable PGE and BMS mineralisation. The motivation behind this study was to aid mining geologists in targeting mineralisation irrespective of the farm. It is known that the Platreef generally overlies different footwall lithologies at individual farms. Thus, the aims of this study were firstly to investigate the potential of chemostratigraphy by delineating indices indicative of distinctive lithological layers. These indices were then tied to the second aim; which were to use geochemical vectoring, which is process-based, to target the PGEs at two different farms. This study included three drillcores: from the farms Sandsloot (SS339) and Tweefontein (TN754 and TN200). The footwall units at Tweefontein are shales of the Duitschland Formation and the Penge banded iron formation; and at Sandsloot it is the Malmani Subgroup dolomites. Samples included 121 quarter cores, used for petrographical and geochemical studies. The elemental rock composition was determined by XRF and ICP-OES analyses. The approach also included statistical and mass balance methods to understand the geological and geochemical controlling processes. Initially, the Platreef package at both farms was petrographically divided into three main layers: pyroxenite, and two distinctive feldspathic pyroxenites (FP-I and FP-II). However, the pyroxenites were also further separated as P-I and P-II, because of a higher notable difference in the degree of alteration within P-I. Progressive degrees of metasomatism were further observed in the lithologies, e.g. within the Platreef package, where feldspathisation was potentially the main metasomatic process. Many geochemical plots (corroborated by the petrographical and mass balance results) illustrated that the feldspathisation were linked to an increase in the content of Al₂O₃ and CaO, and coupled with a decrease in content of Fe₂O₃ and MgO. Together with other geochemical trends, geochemically distinct units of the Platreef package could be discriminated with a metasomatism index (MI; CaO + 10Na₂O / CaO + 10Na₂O + Fe₂O₃ + MgO). The ensuing MI is lowest for the P-II pyroxenite and shows a progressive increase through FP-I, P-I to the highest values in FP-II. Geochemical layering were also observed in the calcsilicates and hornfels; e.g. a progressive decrease in the content of Fe₂O₃, Al₂O₃, Ce, Co, Cu, Ni, Zn, Zr, Au, Pd and Pt from the hornfels subunits H-I, H-II to H-III and an increase in of SiO₂, Fe₂O₃, TiO₂, SO₃, Co, Cu, Ni, Rb, V and Zn content from CS-I, CS-II to CS-III. Correlating the pyroxenites and feldspathic pyroxenites spatially from one drillcore to another were hindered, hence, chemostratigraphy were not completed. In terms of vectoring, it was essential to establish a possible link between the metasomatism index and the nature and style of the PGE and/or BMS mineralisation. The Hornfels subunit H-I and calcsilicate subunit CS-III were the main carriers of BMS and PGE. The Platreef package were more complicated: P-I (low PGE, low BMS); P-II (low PGE, high BMS); FP-II (high PGE, low BMS); and FP-I (high PGE, high BMS). Element indices (e.g. Cu+Ni and Co+Zn) were developed to define a consistent gradient indicative of these ore subunits. A validation process to assess the metasomatism index (MI), base metal indices and PGE distribution within the individual drillcores (TN754, TN200 and SS339) were then undertaken. The results were that the MI ranges were similar in all drillcores, and discriminated the subunits of the Platreef package, gabbronorites and even the calcsilicates. The base metal ratios (e.g. Ni/Co and Cu/Co) were indicative of the PGE rich zones. Trends of the base metal ratios reflected a strong positive relationship with the MI within the Platreef package and the calcsilicates. However, the opposite trend is observed with the hornfels. In conclusion, the MI could potentially be a strong vector of high PGE and BMS mineralisation. It is also possible to discriminate lithologies within the Platreef package with the MI. However, it should be noted that the limitation of this study is that the results are based on three drillcores. The Platreef is heterogeneous at individual farms and extremely diverse across the northern limb. Therefore, future research could be undertaken to validate these findings, by using a bigger drillcore database.
National Research Foundation
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Escalante, Aramburu Abraham David. "Patterns of distal alteration zonation around Antamina Cu-Zn skarn and Uchucchacua Ag-base metal vein deposits, Peru : mineralogical, chemical and isotopic evidence for fluid composition, and infiltration, and implications for mineral exploration." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1548.
Повний текст джерелаАнотація:
Intrusion-related, carbonate rock–hosted replacement deposits are an important source of global base metal production that includes: Cu-Zn skarn, Zn-Pb-Ag carbonate replacement and Ag-base metal deposits. These deposits are located in multiple geological settings and are commonly associated with low-grade Cu-Mo calc-alkaline porphyry districts. Visible alteration halos to these deposits range from ten to hundreds of metres around high temperature skarn deposits, being small to imperceptible around the distal relatively low temperature members of this clan. Patterns of visible and cryptic alteration are described and constrained in this study particularly around paleo-fluid flow zones at different distances and elevations from the ore centre. This was done in order to identify the large-scale zonation, mechanisms, and effects of fluid infiltration especially into the distal portions of these deposits. The main alteration tracers employed included mineralogy, major and trace element geochemistry, oxygen and carbon isotopes, and the fluorescent signature of calcite veins associated with the fluids conduits. Two areas were selected for this study: the large Cu-Zn Antamina skarn and the Ag-base metal Uchucchacua vein deposits in the Peruvian Central Andes as these deposits represent the end-members of the polymetallic carbonate rock-hosted deposits and hence, provide an excellent opportunity to examine the margins and upper sections of these hydrothermal systems.
Geochronological analyses of intrusive dikes were used to establish the magmatic and hydrothermal evolution associated with mineralization, as well as the genetic linkage between proximal and distal portions of the mineralizing system at Antamina. Oxygen, carbon and strontium isotope data of vein minerals is also used to constrain the temperature of the fluids proximal and distal to the magmatic centre. Chemical data of fluorescent and non-fluorescent veins were used to determine the main activators of fluorescence and to constrain its relationship with mineralizing fluids.
In summary, results of this research identify a large-scale zonation of visible and cryptic alteration around paleo-fluid flow zones demonstrating the linkage between Ag-base metal veins, replacement and skarn deposits. Anomalous halos determined throughout Antamina and Uchucchacua deposits may contribute to the development of a more systematic exploration methodology for these types of deposits.
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Sorayadoost, Narjes Sabety. "Soil geochemical exploration of the presidio mine, shafter mining district, Presidio County, Texas /." 2006. http://proquest.umi.com/pqdweb?did=1216761851&sid=3&Fmt=2&clientId=10361&RQT=309&VName=PQD.
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van, Geffen Pim Wilhelmus Gerardus. "GEOCHEMICAL INDICATORS OF BURIED SULPHIDE MINERALISATION UNDER SEDIMENTARY COVER NEAR TALBOT LAKE, MANITOBA." Thesis, 2011. http://hdl.handle.net/1974/6515.
Повний текст джерелаАнотація:
The Paleoproterozoic Talbot volcanogenic massive sulphide (VMS) Cu-Zn occurrence is
located near Talbot Lake, Manitoba, about 80 km south of Snow Lake. The mineralised system is
unconformably overlain by more than 100 m of Paleozoic dolomite sequences and Quaternary
glacial till. The clay fraction of the till contains pronounced anomalies of Zn, Cu, Ag, Pb, Au,
Mn, Hg, Cd, Co, Bi and Se, which is ascribed to the formation of clay-humic complexes that
have carbon-isotopic compositions of δ13C < -20‰. A VMS origin of the near-surface anomaly
is confirmed by distinctly low 206Pb/204Pb ratios, compared to a more radiogenic till signature.
The overall low 206Pb/204Pb ratios in the organic surface media black spruce bark, moss and
humus also indicate input from a magmatic sulphide source, but likely reflect windblown material
from the Flin Flon smelter stack at 160 km to the northwest. Black spruce tree rings that pre-date
industrial sources of atmospheric metal input are used to measure historical element distributions
because they record the local geochemistry at the time of heartwood growth and their root
systems tap into large volumes of soil. At the Talbot prospect, the presence of secondary Zn from
the till in black spruce tree cores is reflected in the Zn/Ca ratio, which eliminates the effect of
dolomite-derived Zn. The process of element migration from buried mineralisation to the surface
is complex and includes oxidation of sulphides, mobilisation and complexation of metal ions,
physical upward transport, and deposition of indicator elements near the surface in accessible
sampling media. To account for a significant influx of indicator elements into the relatively
recently deposited till blanket, post-glacial groundwater upwelling is proposed to act as a major
mechanism driving upward element migration.Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2011-05-14 04:38:36.886
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McKinnon, Adam R., University of Western Sydney, College of Health and Science, and School of Natural Sciences. "A geochemical exploration model for ore deposits in the Cobar Basin." 2007. http://handle.uws.edu.au:8081/1959.7/14967.
Повний текст джерелаАнотація:
The supergene mineralogy and geochemistry of numerous deposits in the Cobar region have been systematically explored in this study, with a particular focus on the oxidised zones of the Endeavour, Mineral Hill and New Cobar orebodies. A recurring pattern was identified in the oxidised mineral assemblages of the region, characterised by a multiple-stage paragenesis. Comprehensive geochemical modelling based on equilibrium processes was undertaken to elucidate the geochemical conditions under which the various assemblages formed. The exercise was extended in a series of experiments concerning the interaction of ground and vadose waters with secondary mineral species. This has led to a self-consistent geochemical exploration model for deposits in the Cobar basin. The model promises to be very useful for exploration in highly weathered terrains, particularly where the deposits lack significant surface expression. A similar approach may be relevant to exploration in other areas around Australia and world-wide.Doctor of Philosophy (PhD)
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McKinnon, Adam R. "A geochemical exploration model for ore deposits in the Cobar Basin." Thesis, 2007. http://handle.uws.edu.au:8081/1959.7/14967.
Повний текст джерелаАнотація:
The supergene mineralogy and geochemistry of numerous deposits in the Cobar region have been systematically explored in this study, with a particular focus on the oxidised zones of the Endeavour, Mineral Hill and New Cobar orebodies. A recurring pattern was identified in the oxidised mineral assemblages of the region, characterised by a multiple-stage paragenesis. Comprehensive geochemical modelling based on equilibrium processes was undertaken to elucidate the geochemical conditions under which the various assemblages formed. The exercise was extended in a series of experiments concerning the interaction of ground and vadose waters with secondary mineral species. This has led to a self-consistent geochemical exploration model for deposits in the Cobar basin. The model promises to be very useful for exploration in highly weathered terrains, particularly where the deposits lack significant surface expression. A similar approach may be relevant to exploration in other areas around Australia and world-wide.
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FANG, JIAN-NENG, and 方建能. "Geochemical exploration in the vicinity of the Chinkuasihih gold-copper deposits." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/16522775013974787947.
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Lyon, W. A. "Geochemical analysis of the regolith of Kangaroo Island: using portable XRF to recognize geochemical signatures and to distinguish lithogeochemical horizons and vectors toward mineralization." Thesis, 2014. http://hdl.handle.net/2440/110491.
Повний текст джерелаАнотація:
This item is only available electronically.Mineralisation overlain by extensive cover can be identified through the geochemical signature dispersed through the surrounding regolith. This project aimed to use portable XRF (pXRF) analysis to increase the understanding of the regolith geochemistry in the proximity of the Cygnet-Snelling Shear Zone (CS-SZ), Kangaroo Island. The shear zone is significant as it hosts several potentially economic deposits including the Bonaventura Copper (Cu) deposit as well as the Dewrang and Kohinoor Lead - Zinc (Pb-Zn) prospects. By using pXRF analysis at 2m intervals on drill hole transects taken from the vicinity of the CS-SZ it was hoped to be able to discern known pathfinder elements associated with Cu, Pb and Zn mineralisation. The data collected from these transects can be used to develop a model of the regolith sequence lithogeochemistry, and to determine which elements can be reliably analysed by pXRF within a regolith sequence such as that seen on Kangaroo Island. The study has also attempted to identify any geochemical signatures associated with Cu, Zn or Pb mineralisation, their spatial extent and potential as geochemical vectors towards mineralisation.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2014
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Crawford, S. J. "Geochemical alteration associated with uranium roll front mineralisation in the Lake Frome Basin." Thesis, 2014. http://hdl.handle.net/2440/109971.
Повний текст джерелаАнотація:
This item is only available electronically.Sedimentary uranium systems represent a significant source of economically recoverable material, with deposits frequently clustered where conditions are favourable for roll-front formation. Exploration for sedimentary uranium usually attempts to target redox fronts within paleochannels or clastic sedimentary sequences which could be potential sites for roll front style uranium mineralisation. Sediments altered by oxidation can be re-reduced at a later date by bacteria making it difficult to determine if an oxidised fluid has moved through the sequence. The movement of oxidising fluids through sediment will inevitably alter both the chemistry of the sediment and the fluid supplying uranium. Elements which are sensitive to redox conditions dissolve and precipitate as conditions change creating a recognisable geochemical footprint. In particular the uranium, molybdenum and arsenic contents of the sediments are changed in a way which is not reversed by re-reduction. These changes are distinctive enough to be detected using a handheld X-Ray fluorescence device which enables rapid decision making in the field even if traditional methods allow for far greater precision and accuracy. The findings of this study describe geochemical changes linked to oxidation in the Pepegoona East and Pannikan deposits, Lake Frome region, South Australia, for use as an exploration tool. It is hoped that by studying changes in the chemistry of these sediments that we may not only improve the efficiency of exploration but also gain a better understanding of how the fluids responsible for uranium mineralisation evolve over time. The addition of data from new deposits will enhance the accuracy of the data set and provide a better understanding of how sediment composition effects alteration.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2014
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Barberes, Gabriel de Alemar. "Unconventional methods for unconventional plays - Surface geochemical prospecting for hydrocabron exploration at South Portuguese Zone." Doctoral thesis, 2018. http://hdl.handle.net/10316/80742.
Повний текст джерелаАнотація:
Tese de doutoramento em Geologia, no ramo de Recursos Geológicos e Ambiente, apresentada ao Departamento de Ciências da Terra da Faculdade de Ciências e Tecnologia da Universidade de CoimbraThe price and reliability of energy supplies, electricity in particular, are key elements in a country’s energy supply strategy. Electricity prices are of particular importance for international competitiveness, as electricity usually represents a significant proportion of total energy costs for industrial and service-providing businesses. In Portugal, the price of electricity and natural gas are among the highest in Europe Union. According to International Energy Agency, in 2016 20% of the electricity was generated by natural gas (52% of total electricity generation was made by fossil fuels) in this country. This project aims to identify onshore hydrocarbon emanations by surface geochemical prospecting, rock-eval pyrolysis analysis and thorium normalization/hydrocarbon anomalies, in order to characterized an unconventional petroleum system in South Portuguese Zone (Portugal). This thesis also aims demonstrate a correlation between airborne gamma radiation data and high-resolution satellite images WorldView-2, in order to be an alternative way and facilitate the acquisition of radiometric data, in view of the high costs associated to an airborne gamma ray survey. A total of 31 samples were collected for rock-eval pyrolysis performed by Weatherford Laboratories and Polish Geological Institute, financed by Repsol E&P (Spain), Partex Oil&Gas (Portugal) and Polish Geological Institute (Poland). The collection of all samples for surface geochemical prospecting was performed using Isojars, with distilled water and a bactericide added to inhibit any bacterial activities. Twenty-seven soil samples were collected for this study, using a drilling machine, a metal tube and a hammer. Thirty-one water samples were collected from artesian wells, boreholes and springs. The remote sensing methodologies, used to define the sampling areas, proved to be very efficient to show possible hydrocarbon emanations. From the geological prospecting point of view the presence of hydrocarbon gases in South Portuguese Zone formation is clear and evident. They are present in soil and water, with significantly high levels.
O preço e a confiabilidade dos estoques de energia, eletricidade em particular, são elementos essenciais na estratégia de fornecimento de energia de um país. Os preços da eletricidade são de particular importância para a competitividade internacional, já que a eletricidade geralmente representa uma proporção significativa dos custos totais de energia para a industria e prestação de serviços. Em Portugal o preço da eletricidade e do gás natural estão estre os mais caros da União Europa. De acordo com a Agência Internacional de Energia, em 2016 20% da eletricidade foi gerada por gás natural (52% do total da geração elétrica foi feita por combustíveis fósseis) neste país. Este projeto tem como objetivo identificar emanações onshore de hidrocarbonetos através da prospecção geoquímica de superfície, análise de pirólise rock-eval e normalização de tório/anomalia de hidrocarbonetos, a fim de caracterizar um sistema petrolífero não-convencional da Zona Sul Portuguesa (Portugal). Esta tese também pretende demonstrar uma correlação entre dados de radiação gama e imagens de satélite de alta resolução WorldView-2, a fim de ser uma alternativa e facilitar a aquisição de dados radiométricos, tendo em vista os altos custos associados ao levantamento aéreo de radiação gama. Um total de 31 amostras foram utlizadas para análises de pirólise rock-eval, tendo sido realizadas pelos laboratórios da Weatherford e do Insituto Polaco de Geologia, e sendo financiadas pela Repsol E&P (Espanha), Partex Oil&Gas (Portugal) e Instituto Polaco de Geologia (Polônia). Toda a amostragem para a prospeção geoquímica de superfície foi feita utilizando frascos Isojars, com água destilada e adicionando bactericida, para inibir qualquer atividade bacteriana. Vinte e sete amostras foram colhidas para este estudo, utilizando uma caroteadora, um tubo metálico e uma marreta. Trinta e uma amostras de água foram colhidas em poços artesianos, furos e nascentes. As metodologias de detecção remota, utilizadas para definir as zonas de amostragem, mostraram-se bastante eficientes na indicação de zonas com possíveis ocorrências de emanações de hidrocarbonetos. Do ponto de vista da prospecção geológica a presença de hidrocarbonetos gasosos nas formações da Zona Sul Portuguesa é clara e evidente. Eles estão presentes no solo e na água, em quantidades significativas
Sciences Without Borders program (CNPq Brazil) – 201943/2014-0; Statoil ASA (CNPq); DigitalGlobe Foundation; Centro de Geociências (FCT); Centro de Interpretação da Terra e do Espaço (FCT); Instituto Dom Luiz (FCT)