Relevant bibliographies by topics / Calcrete geochemistry

Academic literature on the topic 'Calcrete geochemistry'

Author: Grafiati
Published: 10 December 2022
Last updated: 29 January 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Calcrete geochemistry.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Calcrete geochemistry"

1

Kadİr, S., M. Eren, T. Külah, N. Önalgİl, M. Cesur, and A. Gürel. "Genesis of Late Miocene-Pliocene lacustrine palygorskite and calcretes from Kırşehir, central Anatolia, Turkey." Clay Minerals 49, no. 3 (June 2014): 473–94. http://dx.doi.org/10.1180/claymin.2014.049.3.09.

Full text
Abstract:
AbstractThis paper addresses the mineralogy, geochemistry, and genesis of palygorskite and associated calcretes in the Kırşehir region. In this area, the Quaternary calcretes are present within and/or on lacustrine mudstones of the Kızılırmak Formation (Late Miocene-Pliocene). The calcretes occur in the form of nodules, tubes, fracture-infills, and hard laminated crusts (hardpans). Calcrete samples are predominantly composed of calcite associated with smectite, quartz, feldspar, and minor palygorskite. The lacustrine mudstone samples consist mainly of smectite and palygorskite with minor calcite, quartz, feldspar, illite, kaolinite and amorphous material. Petrographic studies revealed that the calcrete samples are predominantly micrites that were partially converted to microsparites by recrystallization. Scanning and transmission electron microscopy images indicate that palygorskite fibres formed authigenically on and between calcite rhombs in the calcrete samples and at the edges of smectite flakes of host rocks adjacent to the calcretes. The oxygen and hydrogen stable isotope values of the calcite suggest that it precipitated from meteoric water under arid or seasonally arid climatic conditions. Calcite precipitation occurred in the vadose zone, as evidenced by desiccation cracks and vadose pisolites. The enrichment of Rb+Ba±Sr and Light Rare Earth Elements (LREE) relative to Heavy Rare Earth Elements (HREE)with a distinct negative Eu anomaly are responses to the fractionation of volcanogenic feldspar and hornblende under the influence of meteoric water. The palygorskite associated with calcretes was precipitated from alkaline water rich in Si, Al and Fe and low in Mg. The palygorskite precipitation occurred at increased temperatures, characterising the advanced stage of calcrete formation which lowers the Ca content in the soil water. The required chemical elements for palygorskite and calcite were most likely derived from the dissolution of smectitic clays, ignimbrites and carbonate minerals.
APA, Harvard, Vancouver, ISO, and other styles
2

Larrey, Marine, Frédéric Mouthereau, Emmanuel Masini, Damien Huyghe, Eric C. Gaucher, Aurélien Virgone, and Véronique Miegebielle. "Quaternary tectonic and climate changes at the origin of travertine and calcrete in the eastern Betics (Almería region, SE Spain)." Journal of the Geological Society 177, no. 5 (June 2, 2020): 939–54. http://dx.doi.org/10.1144/jgs2020-025.

Full text
Abstract:
Continental carbonate bodies are widespread in the Tabernas basin, eastern Betic Cordillera. Their relationships with the topographic evolution, climate changes and extensional regional tectonic processes recognized in the region are, however, still unclear. Travertine deposits exhibit facies of cascade and pool environments often reported as related to water–air surface processes. Calcretes show a large panel of facies, indicating control by groundwater and pedogenic processes. New U/Th dates on both travertine and calcrete reveal that they precipitated from 354 ka ± 76 to 8 ka ± 0.2. The U/Th dates obtained on calcretes are in good agreement with global climate changes and support that precipitation of recent CaCO3 is episodic and occurs mainly during warm and wet conditions. C and O stable isotope geochemistry reveals travertines are thermogenic and characterized by hydrothermal fluids enriched in CO2 that interacted with aquifers. This thermogenic origin suggests a deep source of CO2 (higher positive δ13C values) likely triggered by the presence of an anomalously hot mantle that reflects thinning of the regional lithosphere and volcanism. Further analyses of the distribution of calcrete show they are carbonate-rich fluvial terraces, whose formation is controlled by the response of the river network to regional uplift and climate.Supplementary Materials: reproducibility for δ13C and δ18O of the NSB-18 internal standard available in Supplementary Table 1 (SP1) and reproducibility for U and Th of the HU-1 standard available in Supplementary Table 2 (SP2) at https://doi.org/10.6084/m9.figshare.c.4996514
APA, Harvard, Vancouver, ISO, and other styles
3

Rodrigues, Ana Luísa, Maria Isabel Dias, Maria Isabel Prudêncio, Fernando Rocha, Francisco Ruiz Muñoz, Rosa Marques, María Luz González-Regalado, Dulce Russo, and Guilherme Cardoso. "Paleoenvironmental considerations based on geochemistry and mineralogy of a Miocene lacustrine calcrete, southern Portugal." E3S Web of Conferences 98 (2019): 06012. http://dx.doi.org/10.1051/e3sconf/20199806012.

Full text
Abstract:
A lacustrine carbonate facies has been investigated in Middle Miocene successions of the western side of the Moura-Marmelar basin, Southern Portugal in order to evaluate paleoenvironments in which carbonates formed, by using geochemistry and mineralogy. The studied formation corresponds to a recent unearthed section of a calcrete with an homogeneous carbonate facies comprising fine, whitish, and powdery material, and the only detected difference is a slightly hardness decrease towards the top, as well as an increase of weathered rock fragments (schist). The calcrete is calcium rich, even some magnesium enrichment was observed at the middle level, which is differentiated by a general depletion of all chemical elements, particularly REE, in both the bulk and clay-size fraction. Regarding the mineralogy, calcite prevails, and dolomite is only present in the middle level of the calcrete, together with a smectite enrichment, suggesting changes to more alkaline and low drainage, lacustrine and arid to semi-arid conditions.
APA, Harvard, Vancouver, ISO, and other styles
4

Wang, Yifeng, Daniel Nahon, and Enrique Merino. "Geochemistry and dynamics of calcrete genesis in semi-arid regions." Chemical Geology 107, no. 3-4 (July 1993): 349–51. http://dx.doi.org/10.1016/0009-2541(93)90207-y.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Lintern, M. J. "The association of gold with calcrete." Ore Geology Reviews 66 (April 2015): 132–99. http://dx.doi.org/10.1016/j.oregeorev.2014.10.029.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Phani, P. Ramesh Chandra, and M. Srinivas. "Calcrete Geochemistry in identifying Kimberlite Lamproite Exploration Targets -A case study from Nalgonda district, Telangana, southern India." International Journal of Trend in Scientific Research and Development Volume-2, Issue-2 (February 28, 2018): 964–73. http://dx.doi.org/10.31142/ijtsrd9575.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Reith, Frank, Steven A. Wakelin, Adrienne L. Gregg, and Andreas Schmidt Mumm. "A microbial pathway for the formation of gold-anomalous calcrete." Chemical Geology 258, no. 3-4 (January 2009): 315–26. http://dx.doi.org/10.1016/j.chemgeo.2008.10.023.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Hall, S. M., B. S. Van Gosen, J. B. Paces, R. A. Zielinski, and G. N. Breit. "Calcrete uranium deposits in the Southern High Plains, USA." Ore Geology Reviews 109 (June 2019): 50–78. http://dx.doi.org/10.1016/j.oregeorev.2019.03.036.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Simpson, C. J., J. R. Wilford, L. F. Macias, and R. J. Korsch. "SATELLITE DETECTION OF NATURAL HYDROCARBON SEEPAGE: PALM VALLEY GAS FIELD, AMADEUS BASIN, CENTRAL AUSTRALIA." APPEA Journal 29, no. 1 (1989): 196. http://dx.doi.org/10.1071/aj88019.

Full text
Abstract:
Digital image processing of advanced aircraft and Landsat Thematic Mapper (TM) satellite remotely sensed data over sandstones of the Palm Valley Gas Field, central Australia, showed a distinct colour anomaly about 6 km long by 1.5 km wide which is not obvious in visible wavelength imagery. Field inspection showed that the colour anomaly was characterised by different rock- weathering colour, a geobotanical anomaly, calcium carbonate precipitation within rock fractures, and different soil pH. Inorganic rock geochemistry indicates significant chemical differences in some major elements. A limited number of soil gas samples were analysed and within the remotely sensed colour anomaly some had above- threshold concentrations of methane, ethane, propane and butane. Preliminary processing of airborne magnetic and gamma spectrometric data over the anticline did not indicate any significant values that suggested abnormal development of magnetite or clay minerals within the colour anomaly. Carbon and oxygen isotope analyses on calcrete from within the colour anomaly suggest, somewhat inconclusively, that hydrocarbons have not contributed significantly to the formation of the calcium carbonate component of the calcrete. Consideration of all available information suggests that the colour anomaly detectable by aircraft and Landsat TM satellite remote sensing corresponds to a zone of surface alteration resulting from long- term seepage of hydrocarbon gases. This colour anomaly, the first of its type reported from Australia, was detected because of spectral reflectance differences resulting from a combination of increased soil carbonate and different geobotanical characteristics from those of the surrounding terrain.
APA, Harvard, Vancouver, ISO, and other styles
10

Neymark, L. A. "Potential effects of alpha-recoil on uranium-series dating of calcrete." Chemical Geology 282, no. 3-4 (March 23, 2011): 98–112. http://dx.doi.org/10.1016/j.chemgeo.2011.01.013.

Full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Calcrete geochemistry"

1

Wolff, Keryn Dianne. "Regional Carbonate Geochemistry and Biogeochemistry for Cu Exploration on the Yorke Peninsula, South Australia." Thesis, 2018. http://hdl.handle.net/2440/120233.

Full text
Abstract:
This thesis describes the geochemistry from carbonate rocks and biogeochemistry from mallee across the Yorke Peninsula to better characterise and define mineral systems that may occur in IOCG prospective basement rocks masked by various overlying cover sequences. Presented here is geochemical data from three cliff escarpments (vertical geochemical profiles) which preserve cover sequences overlying basement rocks. Ca/Sr ratios were found to be a defining discriminator between marine and pedogenic carbonate rocks within the profiles; pedogenic carbonates have Ca/Sr ratios less than 650 and marine carbonates have Ca/Sr ratios greater than 1260. This simple discriminant can also be used to identify samples appropriate for carbonate sampling in mineral exploration, particularly in drill cuttings, as well as retrospective filtering of multi-element geochemical exploration data sets. A regional sampling program was undertaken in the context of the regolith landform setting from a newly constructed map of Yorke Peninsula. The majority of carbonate material occurring at the surface across the Yorke Peninsula has Ca/Sr <650, with lesser occurrences of carbonate preserving Ca/Sr ratios between 650 and 1260 and one preserving marine Ca/Sr >1260. The majority of surface carbonates have Ca/Sr consistent with a mixture of rainfall sources and marine carbonate sources. With the dominant contributor of Ca and Sr from rainwater. Surface carbonates with Ca/Sr ratios >650 have a greater proportion of Ca and Sr sourced from marine carbonates, incorporated either from wind-blown dust or from in-situ marine carbonates. The systematically lower Ca/Sr of rainwater, compared to marine carbonates, translates into systematically lower Ca/Sr in pedogenic compared to marine carbonates. This is an effective discriminator of carbonates formed by pedogenic processes and weathered marine carbonates. The dominantly pedogenic nature of the carbonate rocks sampled across the Yorke Peninsula means that they are appropriate for use in mineral exploration geochemistry for underlying iron oxide-copper-gold deposits. The range of the Cu values in the carbonate rocks is 1.4–36ppm. Elevated Cu concentrations (1.4–36ppm) occur more commonly within carbonate rocks within 3km of known Cu occurrences. . Eucalyptus foliage was collected at a suitable time of year to maximise root absorption and minimise contamination from farming practices. The range of Cu concentrations within Eucalyptus with mallee-form was 1.6–10ppm. Mallee within 3km of known mineralisation has a concentration of 2–10ppm Cu. There was little statistical difference between the four mallee species sampled so that it is reasonable to use all data as a collective dataset. As mallee occur across a large portion of southern Australia, this method of sampling could prove to be a useful tool for frontiers in exploration where tenure occurs typically over large areas, with widespread cover and restricted access due to environmental and cultural sensitivities.
Thesis (Ph.D.) -- University of Adelaide, School of Physical Sciences, 2019
APA, Harvard, Vancouver, ISO, and other styles
2

Klingberg, L. L. "Regolith-landforms and regolith geochemistry of the ‘Tomahawk’ Au-in-calcrete anomaly: Tunkillia, Gawler Craton, South Australia." Thesis, 2009. http://hdl.handle.net/2440/129278.

Full text
Abstract:
This item is only available electronically.
The ‘Tomahawk’ Au-in-calcrete anomaly is a zone of peak Au-in-calcrete content within the Tunkillia prospect of the central Gawler Craton, South Australia. Exploration drilling of this area has failed to intersect significant underlying mineralisation, making this an important setting to investigate controls on linkages between Au-in-calcrete expression and possible mineralisation sources. This study is the first to consider the multi-element geochemical characteristics of calcretes at ‘Tomahawk’ rather than using the Au-only approach of previous geochemical exploration. This investigation also considers the potential for laterally dispersed geochemical signatures across the landscape recorded at the surface of Au and associated elements, and suggests that Au was, and may still be physically mobilised along old and contemporary alluvial drainage depressions. There is a low relief, but locally significant drainage divide to the south of ‘Tomahawk’, so the anomaly area is associated with a point of low, broad confluence of several north flowing palaeodrainage depressions. The interpretation of these palaeolandscape controls further builds on palaeodrainage channel identification from previous studies and supports hypotheses that ‘Tomahawk’ is in an upper catchment setting, relative to the ‘Area 191’ Au-in-calcrete anomaly. Primary Au mineralisation at Tunkillia is associated with pyrite, minor galena and sphalerite within quartz-sulphide veins, and has a geochemical association with Au, Ag, Pb and Zn. Supergene Au enrichment has been recognised within ferruginised saprock overlying mineralised bedrock, and this is largely considered Au-only mineralisation. The calcrete geochemistry here shows some distinction between possible primary and secondary Au occurrences based in the trace element characteristics. The Au-in-calcrete concentrations obtained in this study are up to 194 ppb within CHep and ISps2 regolith-landforms in the north of the study area, corresponding to the lower margins of topography and areas interpreted to be within palaeodrainage systems. Silver concentrations above detection were found in association with many of the elevated Au results, therefore identifying areas of interest and possible alteration halos surrounding primary Au mineralisation. Furthermore, small exposures of weathered in situ quartz veins support a possible source for the ‘Tomahawk’ Au-in-calcrete anomaly to the south, which is immediately upslope of the palaeodrainage system.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2009
APA, Harvard, Vancouver, ISO, and other styles
3

Wittwer, P. D. "Geology and geochemistry of regolith carbonate accumulations of the southwestern Curnamona Province, SA: Implications for mineral exploration." Thesis, 2004. http://hdl.handle.net/2440/123526.

Full text
Abstract:
This item is only available electronically.
Although regolith carbonate accumulations (RCAs) have been extensively used in mineral exploration programs in the regolith-dominated terrains of the Yilgarn and Gawler Cratons, their use has so far been limited within the Curnamona Province, SA. This study shows how the detailed characterisation of RCAs in the southwestern Curnamona Province enhances their use in mineral exploration programs at the regional to prospect scales. A regional RCA distribution map for the study area shows that RCAs are generally widespread, although certain RCA morphological facies are dominant in different parts of the landscape, and in some areas RCAs are absent or at best a very minor component of the regolith. A dataset of whole rock geochemical assays of RCAs provides the basis of graphical presentations and geochemical maps that highlight the chemical characteristics of RCAs proximal to areas of known Au mineralisation in contrast to more distal samples. Several Au pathfinder elements in RCA assays were found to include As, W, Bi, and Mo, and greatly assist in further anomaly definition when used in conjunction with Au assays. Major element composition (e.g. Ca, Mg, Fe) showed little relationship to local landform setting, however, landscape setting appears to be a more important control on Au assay results both at the regional and prospect scales. Gold distribution in the area was independent of the presence of major elements such as calcium and magnesium. Microprobe analysis showed that Au was rare and invisible at the resolution of the analysis and existed in the calcium carbonate matrix as well as in detrital material. The composition of the underlying rock lithologies was also compared to the whole rock chemistry of the RCAs and showed the possibilities of this technique to aid geological mapping in regolith-dominated terrains and to assist in locating mineralised systems.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2004
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Calcrete geochemistry' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography