Academic literature on the topic 'Honours; Geology; geochronology'

On June 30, 1984, Bill Mathews retired from full-time teaching in the Department of Geological Sciences at the University of British Columbia (UBC). On October 10, 1984, a large group of his friends and admirers met in a symposium to honour his immense contributions to science and to students of the Earth, but more importantly, to celebrate his continuing intense scientific activity. His personal and scientific vigour continues unabated, and "retirement" only means the opportunity to concentrate on his research, full-time.Bill Mathews is a phenomenon. It is not easy to keep up with the list of his publications, let alone to emulate his productivity. Since his first scientific publication in 1942, he has written 125 papers, which translates into three papers every year for 42 years! Now that he can devote himself entirely to this work, we can only suppose that this productivity will increase.W. H. Mathews received the B.A.Sc. degree in Geological Engineering from UBC in 1940 and the M.A.Sc. from UBC in 1941 and spent the war years in strategic minerals research with the B.C. Department of Mines, following which he continued his studies, receiving the Ph.D. from University of California, Berkeley, in 1948. In 1951 he joined the faculty at UBC, and he served as Head of the Department of Geology from 1964 to 1971. Dr. Mathews has been honoured by scientific societies and is a Professional Engineer, Fellow of the Geological Society of America, a member of the American Association of Petroleum Geologists and of the Geological Association of Canada, and a Fellow of the Royal Society of Canada.Perhaps the most striking feature of the symposium to honour Bill Mathews was the recognition of the breadth of his contributions. He calls himself a geomorphologist and Quaternary geologist, but the titles of his papers tell a different story. They tell of a man interested in everything at a fundamental and penetrating level, who has made important contributions to glaciology, volcanology, Tertiary tectonics, coal geology, mineral deposits, structural geology, geochronology, sedimentology, stratigraphy, engineering geology, and marine geology. It is very rare to find such a person, who can carry on a high-level scientific conversation with any specialist in the subdisciplines of the Earth sciences. Most of us are content to struggle with some mastery of a single subdiscipline, but Bill's curiosity reaches into every corner. This catholicity of interest has been a wonderful stimulus for his graduate students, undergraduate students, and colleagues.The four papers that follow this introduction were presented at the symposium and are kept together in this issue of the Canadian Journal of Earth Sciences as a tribute to Bill Mathews and in recognition of the astonishing range of his interests and contributions. We are pleased to celebrate in this way his return to full-time research after a career of combining his research with the full-time work of a distinguished professor.As is always the case, many of Bill's scientific friends could not produce a manuscript and symposium lecture in time to appear in this issue. Without exception, however, they join us in our applause of Bill Mathews' distinguished and continuing scientific career.

Tom Krogh revolutionized the field of precise U–Pb geochronology through a series of ground-breaking technical advances in the 1970s and 1980s that changed our investigative approach to understanding geologic processes. Earth scientists around the world have used his dating methods for more than 30 years to produce high-precision ages that have advanced our knowledge of Earth’s evolution through time. Tom applied these techniques to investigate the formation of ancient crust in the Superior and Grenville provinces, and other orogens, and the timing of terrestrial impacts. His legacy is built upon these scientific contributions, the many people he trained and inspired, and the global distribution of laboratories that use his methods.

The Newfoundland Appalachians are a classic area for studying the record of arc development and terrane accretion processes with excellent exposure to different crustal levels that are minimally deformed and metamorphosed. This area also provides a link between the once continuous Appalachian and Caledonian orogens. The Annieopsquotch Accretionary Tract lies along the Red Indian Line, within the peri-Laurentian realm of the central Newfoundland Appalachians. The Darriwilian (468–461 Ma) tectonostratigraphic units of the Annieopsquotch Accretionary Tract are commonly characterized by polymictic volcanogenic conglomerate horizons. A conglomerate horizon at the interface between a suprasubduction zone ophiolite and its calc-alkaline volcanic arc cover sequence is herein investigated for zircon and geochemical provenance. Geochronology revealed a maximum age of deposition of 467 ± 4 Ma with zircon inheritance ranging from ca. 500 to 2800 Ma, consistent with a peri-Laurentian continental basement source. Four types of volcanogenic conglomerate clasts are noted on the basis of lithogeochemistry: arc andesite; calc-alkaline basalt; tholeiitic basalt; and non-arc rhyodacite. Tholeiitic basalt clasts are likely locally derived, perhaps from the underlying Skidder Formation. Other volcanic clasts do not have any known geochemical equivalents in the Annieopsquotch Accretionary Tract and hence appear to be exotic. The dominant zircon population suggests that the exotic clasts were derived from a ca. 467 Ma peri-Laurentian andesitic volcanic arc that once formed part of the Annieopsquotch Accretionary Tract.

Two Permian-Triassic boundary (PTB) successions, Lung Cam in Vietnam, and Lukač in Slovenia, have been sampled for high-resolution magnetic susceptibility, stable isotope and elemental chemistry, and biostratigraphic analyses. These successions are located on the eastern (Lung Cam section) and western margins (Lukač section) of the Paleo-Tethys Ocean during PTB time. Lung Cam, lying along the eastern margin of the Paleo-Tethys Ocean provides an excellent proxy for correlation back to the GSSP and out to other Paleo-Tethyan successions. This proxy is tested herein by correlating the Lung Cam section in Vietnam to the Lukač section in Slovenia, which was deposited along the western margin of the Paleo-Tethys Ocean during the PTB interval. It is shown herein that both the Lung Cam and Lukač sections can be correlated and exhibit similar characteristics through the PTB interval. Using time-series analysis of magnetic susceptibility data, high-resolution ages are obtained for both successions, thus allowing relative ages, relative to the PTB age at ~252 Ma, to be assigned. Evaluation of climate variability along the western and eastern margins of the Paleo-Tethys Ocean through the PTB interval, using d18O values indicates generally cooler climate in the west, below the PTB, changing to generally warmer climates above the boundary. A unique Black Carbon layer (elemental carbon present by agglutinated foraminifers in their test) below the boundary exhibits colder temperatures in the eastern and warmer temperatures in the western Paleo-Tethys Ocean.ReferencesBalsam W., Arimoto R., Ji J., Shen Z, 2007. Aeolian dust in sediment: a re-examination of methods for identification and dispersal assessed by diffuse reflectance spectrophotometry. International Journal of Environment and Health, 1, 374-402.Balsam W.L., Otto-Bliesner B.L., Deaton B.C., 1995. Modern and last glacial maximum eolian sedimentation patterns in the Atlantic Ocean interpreted from sediment iron oxide content. Paleoceanography, 10, 493-507.Berggren W.A., Kent D.V., Aubry M-P., Hardenbol J., 1995. Geochronology, Time Scales and Global Stratigraphic Correlation. SEPM Special Publication #54, Society for Sedimentary Geology, Tulsa, OK, 386p.Berger A., Loutre M.F., Laskar J., 1992. Stability of the astronomical frequencies over the Earth's history for paleoclimate studies. Science, 255, 560-566.Bloemendal J., deMenocal P., 1989. Evidence for a change in the periodicity of tropical climate cycles at 2.4 Myr from whole-core magnetic susceptibility measurements. Nature, 342, 897-900.Chen J., Shen S-j., Li X-h., Xu Y-g., Joachimski M.M., Bowring S.A., Erwin D.H., Yuan D-x., Chen B., Zhang H., Wang Y., Cao C-q, Zheng Q-f., Mu L., 2016. High-resolution SIMS oxygen isotope analysis on conodont apatite from South China and implications for the end-Permian mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology, 448, 26-38.Da Silva A-C., Boulvain F., 2002. Sedimentology, magnetic susceptibility and isotopes of a Middle Frasnian carbonate platform: Tailfer Section, Belgium. Facies, 46, 89-102.Da Silva A.-C., Boulvain F., 2005. Upper Devonian carbonate platform correlations and sea level variations recorded in magnetic susceptibility. Palaeogeography, Palaeoclimatology, Palaeoecology, 240, 373-388.Dettinger M.D., Ghil M., Strong C.M., Weibel W., Yiou P., 1995. Software expedites singular-spectrum analysis of noisy time series. EOS. Transactions of the American Geophysical Union, 76, 12-21.Dinarès-Turell J., Baceta J.I., Bernaola G., Orue-Etxebarria X., Pujalte V., 2007. Closing the Mid-Palaeocene gap: Toward a complete astronomically tuned Palaeocene Epoch and Selandian and Thanetian GSSPs at Zumaia (Basque Basin, W Pyrenees). Earth Planetary Science Letters, 262, 450-467.Ellwood B.B., García-Alcalde J.L., El Hassani A., Hladil J., Soto F.M., Truyóls-Massoni M., Weddige K., Koptikova L., 2006. Stratigraphy of the Middle Devonian Boundary: Formal Definition of the Susceptibility Magnetostratotype in Germany with comparisons to Sections in the Czech Republic, Morocco and Spain. Tectonophysics, 418, 31-49.Ellwood B.B., Wang W.-H., Tomkin J.H., Ratcliffe K.T., El Hassani A., Wright A.M., 2013. Testing high resolution magnetic susceptibility and gamma gradiation methods in the Cenomanian-Turonian (Upper Cretaceous) GSSP and near-by coeval section. Palaeogeography, Palaeoclimatology, Palaeoecology, 378, 75-90.Ellwood B.B., Wardlaw B.R., Nestell M.K., Nestell G.P., Luu Thi Phuong Lan, 2017. Identifying globally synchronous Permian-Triassic boundary levels in successions in China and Vietnam using Graphic Correlation. Palaeogeography, Palaeoclimatology, Palaeoecology, 485, 561-571.Ghil M., Allen R.M., Dettinger M.D., Ide K., Kondrashov D., Mann M.E., Robertson A., Saunders A., Tian Y., Varadi F., Yiou P., 2002. Advanced spectral methods for climatic time series. Reviews of Geophysics, 40, 3.1-3.41. http://dx.doi.org/10.1029/2000RG000092.Gradstein F.M., Ogg J.G., Smith A.G., 2004. A geologic Time Scale 2004. Cambridge University Press, England, 589p.Hartl P., Tauxe L., Herbert T., 1995. Earliest Oligocene increase in South Atlantic productivity as interpreted from “rock magnetics” at Deep Sea drilling Site 522. Paleoceanography, 10, 311-326.Imbrie J., Hays J.D., Martinson D.G., McIntyre A., Mix A.C., Morley J.J., Pisias N.G., Prell W.L., Shackleton N.J., 1984. The Orbital Theory of Pleistocene Climate: Support from a Revised Chronology of the Marine Delta 18O Record. In Berger A.L., Imbrie J., Hays J., Kukla G., Saltzman B. (Eds.), Milankovitch and Climate, Part I, Kluwer Academic Publishers, 269-305.Mead G.A., Yauxe L., LaBrecque J.L., 1986. Oligocene paleoceanography of the South Atlantic: paleoclimate implications of sediment accumulation rates and magnetic susceptibility. Paleoceanography, 1, 273-284.Salvador A., (Ed.), 1994. International Stratigraphic Guide: The International Union of Geological Sciences and The Geological Society of America, Inc., 2nd Edition, 214p.Scotese C.R., 2001. Atlas of Earth History, Volume 1, Paleogeography, PALEOMAP Project, Arlington, Texas, 52p.Scotese C.R., 2013. Map Folio 49, Permo-Triassic Boundary (251 Ma), PALEOMAP PaleoAtlas for ArcGIS, Triassic and Jurassic Paleogeographic, Paleoclimatic and Plate Tectonic Reconstructions, PALEOMAP Project, Evanston, IL, 3.Shackleton N.J., Crowhurst S.J., Weedon G.P., Laskar J., 1999. Astronomical calibration of Oligocene-Miocene time. Philosophical Transactions of the Royal Society London, A357, 1907-1929.Shaw A.B., 1964. Time in Stratigraphy. New York, Mc Graw Hill, 365p.Shen S.-Z., Crowley J.L., Wang Y., Bowring S.A., Erwin D.H., Henderson C.M., Ramezani J., Zhang H., Shen Y.,Wang X.-D., Wang W., Mu L., Li W.-Z., Tang Y.-G., Liu X.-L., Liu X.-L., Zeng Y., Jiang Y.-F., Jin Y.-G., 2011a. High-precision geochronologic dating constrains probable causes of Earth’s largest mass extinction. Science, 334, 1367-1372. Doi:10.1126/science.1213454.Swartzendruber L.J., 1992. Properties, units and constants in magnetism. Journal of Magnetic Materials, 100, 573-575.Weedon G.P., Jenkyns H.C., Coe A.L., Hesselbo S.P., 1999. Astronomical calibration of the Jurassic time-scale from cyclostratigraphy in British mudrock formations. Philosophical Transactions of the Royal Society London, A357, 1787-1813.Weedon G.P., Shackleton N.J., Pearson P.N., 1997. The Oligocne time scale and cyclostratigraphy on the Ceara Rise, western equatorial Atlantic. In: Schackleton N.J., Curry W.B., Richter C., and Bralower T.J. (Eds.). Proceedings of the Ocean Drilling Program, Scientific Results, 154, 101-114.Whalen M.T., Day J.E., 2008. Magnetic Susceptibility, Biostratigraphy, and Sequence Stratigraphy: Insights into Devonian Carbonate Platform Development and Basin Infilling, Western Alberta. Papers on Phanerozoic Reef Carbonates in Honor of Wolfgang Schlager. SEPM (Society for Sedimentary Geology) Special Publication, 89, 291-314.

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U-Pb zircon geochronology indicates deposition of the Cuddapah Supergroup, Cuddapah Basin, India occurred for at least 986 million years. Deposition started after 2502±17 Ma with the deposition of the Gulcheru Formation and ended after 913±11 Ma with the deposition of the Cumbum Formation. Maximum depositional ages have been found for individual formations within the Cuddapah Supergroup; the Pulivendla Formation has a maximum deposition of 1899±19 Ma and the Bairenkonda Formation has a maximum depositional age of 1660±22 Ma. Thermal events during the Palaeoproterozoic present a possible cause of basin formation. At this early stage of the Cuddapah Basin’s evolution the provenance of sediments was the Dharwar Craton, which currently underlies the basin and borders it on the north, south and west sides. The uplift of the Eastern Ghats on the eastern margin affected the evolution of the Cuddapah Basin, changing the shape and the sediments of the basin. Uplift and deformation events in the Eastern Ghats folded the eastern side of the Cuddapah Basin and are responsible for its present crescent shape. The formation of the Eastern Ghats caused increased subsidence to the east, creating an asymmetry in the depth of the basin. The provenance of the sediments of the Cuddapah Supergroup changed to the Eastern Ghats for the deposition of the youngest stratigraphic group, the Nallamalai Group.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2010

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Various igneous bodies have intruded the Palmer area throughout the Delamerian Orogeny. The earliest, the Rathjen Gneiss, intruded either before or during D1 which gave it the prominent foliation. D1 was also responsible for crenulations in migmatite veins throughout the area. These crenelated migmatite veins are in areas folded by D2 mesoscale folds. Some pegmatite veins are also folded by D2 folds. The Palmer Granite intruded during D2 as is seen by shearing in a semi-crystalline state and a tectonic foliation that has been folded. The ballooning of the granite during emplacement deforms the surrounding sediments and the pre-granite folds hence their axes lie parallel to the contact of the granite. The effect of the granite intruding during the deformation has lead to the axis of the D2 folds forming after the granite to have a degree of randomness about their axis. Migmatite grade was reached again after the intrusion of the granite causing melt veins to develop to disrupt the foliation. D3 formed a regional syncline of the area combined with some small scale folding within the granite, however a foliation did not form. The emplacement of the granite and some other igneous bodies throughout the area has been controlled by using the bedding plane of the Kanmantoo. The geochemical trends throughout the Palmer Granite is formed by two different groups fractionally crystallising zircon, amphibole and biotite. This results in a decrease of normally incompatible elements. The two groups form by one group from a homogeneous source and the other a heterogeneous source. The xenoliths crystallised from a mafic magma. The amphibolites form two groups according to their differentiation and genetic relationship. They both form by fractional crystallisation however U and Pb are decreasing cannot be explained by this. Another possible mechanism is liquid un-mixing. To tie all of the groups together a model of a mafic pluton that crystallises the xenoliths as a chilled margin. The mafic magma evolves some of the Palmer Granite whilst turbulently convecting hence homogenising the magma. A magma recharge forms the more evolved mafic and this forms more Palmer Granite which convects in a laminar fashion forming heterogeneities. Part of the mafics evolve enough to be caught up in the Palmer Granite and as it does not crystallise zircons all the fractional crystallisation of the Palmer Granite must have occurred in the mafic plution.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Earth and Environmental Sciences, 1993

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At Toondulya Bluff a sequence of 'older' Gawler Range Volcanics dip in an easterly direction beneath the overlying Yardea Dacite, and are intruded by the comagmatic Hiltaba Granite. The volcanics occur as a series of tuffs and lava flows. Geochemical evidence suggests these volcanics are related to each other by fractional crystallisation, with plagioclase, clinopyroxene, K-feldspar and titan-magnetite, and accessory zircon and apatite controlling differentiation trends. The Si-rich Hiltaba Granite and Yardea Dacite formed from the final, highly fractionated melts. Geothermometry suggests the volcanic and granite crystallised at temperatures within the range 680deg-850degC. The initial magma from which the lithologies were derived, was formed by partial melting of a lower crustal source probably of granulitic composition. Lake Acraman is believed to have been a site of meteoritic impact in the late Proterozoic (~600 Ma ago). Fragments of dacitic ejecta have been identified within the Bunyeroo Formation, Flinders Ranges and dating of these fragments gives an age of c.1575 Ma using single zircon ion probe dating techniques (Gostin et al in prep.). U/Pb dating of the Yardea Dacite at Lake Acraman reveals it to be of comparable age to these fragments (1603-1631 Ma). The lower intercept of the discordia line reveals there has been no resetting of the U/Pb system in response to the postulated meteoritic impact.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Earth and Environmental Sciences, 1985

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An Investigation of the structure of the Kadavur Dome in India’s Southern Granulite Terrain has revealed an absence of domal features, and instead evidence for poly-deformational folding and thrusting. Zircon U/Pb analysis by Laser Ablation Inductively Coupled Mass Spectrometry (LA-ICPMS) reveals that the quartzites of the Kadavur Valley in the north of the Madurai Block were deposited between the late Palaeo- and early Neoproterozoic. The depositional age and the detrital zircon populations found in the Kadavur quartzites are analogous to the depositional age and detrital zircon populations found in the Itremo Group of central Madagascar, which has been identified as a part of the former continent Azania. Metamorphic zircon rim analyses of Kadavur quartzites yield dates of ~840ma and ~882 Ma. These rims are interpreted as a result of contact metamorphism induced by the intrusion of nearby anorthositic gabbros, dated in this study at 825 ± 17 Ma. Thermal Ionisation Mass Spectrometry (TIMS) on whole rock samples of the igneous suite present in the Kadavur area reveal negative εNd values, while evidence of crustal contamination has been found by both Sensitive High Resolution Ion Microprobe (SHRIMP) analysis of oxygen isotopes and LA-Multicollector-ICPMS analysis of Lu/Hf isotopes. Thin section analysis reveals that the igneous suite is divided mineralogically into two broad groups. Major, trace and rare earth element (REE) geochemical analysis of these groups shows that they are also divided chemically. Geochemical discrimination plots of these samples suggest an Island Arc Basalt/Tholeiite petrogenesis. Of particular interest is a felsic gneiss sampled in the Kadavur Valley that has been interpreted as either a tuffaceous/volcanoclastic meta-sediment or felsic intrusive. The implication of this sample being a tuffaceous meta-sediment is that its age would date the Kadavur sequence and hence date the Itremo Group.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2010

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The Alpine Schist is located on the eastern margin of the Alpine Fault, which accommodates oblique collision between the Pacific and Australian plates in New Zealand. Collision has been active since the Cenozoic and exhumation models predict that surface rocks were buried ~20km in the Pliocene. Despite this, fabrics of Mesozoic age are inferred to be preserved at the surface. In order to test the age of fabric formation, transects were conducted across the Alpine Schist to measure the foliation. Rock samples were collected to date the age of zircon and 40Ar/39Ar age of muscovite in order to constrain the age of metamorphism and fabric formation within the Alpine Schist. The structural data displayed two populations of foliations: a dominant foliation tracking towards the orientation of the Alpine Fault and a minor shallower orientation. The geochronological data highlighted ages for the formation and deposition of the Alpine Schist protolith and metamorphism associated with the Rangitata Orogeny. Muscovite 40Ar/39Ar data analysis yielded Pleistocene closure temperatures of the argon system. The heterogeneous foliation orientation and muscovite age suggested differential strain and fabric formation with the Alpine Schist during Plesitocene uplift along the Alpine Fault. The study of the active Southern Alps orogen and constraining the structural and geochronological features will enable more accurate interpretation of fossil orogens and their relationship with plate tectonics.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Earth and Environmental Sciences, 2013

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U/Pb age analyses were conducted on detrital zircons from Khondalites in the Eastern Ghats Belt (EGB) in eastern peninsular India. This study was aimed at determining detrital ages to help understand the nature of the protolith to the metasedimentary rocks. These khondalite terrains make up the most extensive terrains in the EGB yet they are poorly understood. They are important because they help constrain timing of tectonism in the Mesoproterozoic and the formation of Rodinia and Eastern Gondwana. There were very few detrital zircons in the samples collected from the EGB and age analyses could not be made from them. Metamorphic ages were recorded from metamorphic/metamorphically recrystallised zircons. The age of metamorphism recorded in these zircons is approximately 900 Ma. This age agrees with metamorphic ages predicted from previous studies. This metamorphism is a result of the collisional orogeny that amalgamated eastern India with eastern Antarctica in the Mesoproterozoic. A Pan-African overprint has been recorded in the zircon ages which range from 660-560 Ma. These are predicted to be from lead loss due to metamorphism and can be seen on the concordia plots for U/Pb age data.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2010

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Zircon and monazite U–Pb isotope geochronology combined with structural mapping in the Mt Boothby region in the central Aileron Province in Central Australia has constrained the timing of two tectonically distinct phases of high-grade deformation and metamorphism. The first event (D1/M1) occurred at around 1790 Ma and was associated with the emplacement of a bimodal magmatic suite that underwent high-grade deformation prior to the emplacement of voluminous granite also at around 1790 Ma. The timing of D1/M1 coincides with the early stages of the Yambah Event, which is widely recognised in the southern Aileron Province, but has not previously been unequivocally shown to be associated with deformation . Subsequent pervasive reworking occurred over the interval 1600-1570 Ma, and was associated with long-lived granulite-grade metamorphism. The timing of this event coincides with the Chewings Orogeny which largely shaped the tectonic geology further west in the Reynolds and Anmatjira Ranges. During the Chewings Orogeny the c.1790 Ma D1 structures were transposed into a composite S1/S2 fabric. Map scale F2 folding is interpreted to have a shallow plunge suggesting that the S1 fabric may have originally been shallow dipping, raising the possibility that deformation was extensional in nature, and coeval with deposition of the nearby Reynolds Range Group which is constrained to the interval 1806-1785 Ma. Although inferred here to be Yambah aged, the timing constraints for D1 /M1 also overlap with the c. 1800 Ma Stafford Event which was associated with voluminous felsic magmatism, mafic magmatism and extreme geothermal gradient magmatism. This suggests that an extended period of extension, sedimentation, magmatism and deformation may have occurred at around 1800 Ma in the central Aileron Province.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Earth and Environmental Sciences, 2012

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Volcanics in the Kokatha region present a wider range of rock types than in other areas of the Gawler Ranges. High temperature Mg rich basalt flows through to rhyolite ignimbrites and air fall tuffs outcrop. Two magmatic cycles are observed with a cycle consisting of initial basalts, followed by voluminous dacites and rhyodacites. The final phase of the cycle following the rhydacites represents a period of more explosive activity resulting in the deposition of rhyolitic ignimbrites, air fall tuffs rhyolitic flows and pyroclastics. Geochemical data indicate both fractionation and mixing of fractionated components were active igneous processes resulting in the formation of layered magma chambers. The layering of the magma chambers being well illustrated in the stratigraphy of the volcanic pile. Further evidence for cyclic fractionation trends exists, with a relative depletion of incompatible elements in the second cycle when compared to the first cycle. Discrimination diagrams plot the rocks from Kokatha in the calc-alkaline field. Calc-alkaline series usually indicate subduction processes however volcanism at Kokatha is intracratonic. Rb-Sr data give an isochron age of 1588.4 ± 14 Ma suggesting the rocks from Kokatha are a part of the lower sequence of the Gawler Range Volcanics. Samples from both cycles produce the isochron indicating a melt from a homogeneous source. Neodymium data suggest a basaltic input from the mantle assimilating with lower crust is a likely source. A possible tectonic model for volcanism is presented. Initially a flux of mantle-derived basalt enters the lower crust. This provides heat for large scale melting. Assimilation of lower crustal melts and mantle-derived basalts may or may not occur however a homogeneous source is formed. Diapirism resulting in upper crustal magma chambers allows the formation of a layered magma chamber. Eruption of the magma results in the stratigraphic sequence of volcanic rock units.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 1989

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The Coompana Province between the Gawler Craton in South Australia and the Yilgarn Craton in Western Australia is one of the least understood geological regions in Australia. Recent work by Spaggiari and Smithies (2015) suggests that the known crustal precursors in the Coompana Province originated in a new crustal generation event at ca. 1900 Ma. This new juvenile crustal element then evolved through three distinct reworking and magmatic events at ca. 1610 Ma, ca. 1500 Ma, and between ca. 1192 – 1150 Ma (Wade et al., 2007; Spaggiari and Smithies, 2015). Dating of mafic volcanics underlying the Bight Basin in the south-eastern Coompana Province using the Sm-Nd mineral isochron method has revealed a fourth distinctive episode of mafic magmatism at ca. 860 Ma. The geochemical and Nd-isotopic signatures of ca. 860 ma mafic magmatism, including Nb and Ti anomalies, LREE enrichment, K-anomalies, and highly evolved εNd(860Ma) values between -9.9 and -12.7 provide evidence for assimilation and reworking of subduction/arc related Coompana Province crust. Magmatism at ca. 860 Ma in the Coompana Province was most likely coeval with widespread magmatism that occurred over Central and Southern Australia between ca. 800 – 830 Ma. Magmatism during this period was associated with the NE-SW directed intracratonic extension that resulted in the Centralian Superbasin and produced various suites of mafic volcanics and intrusives referred to collectively as the Willouran Basic Province. We suggest that the Willouran Basic Province now be extended to include the ca. 860 Ma mafic volcanics and intrusives in the south-eastern Coompana Province.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2015

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The central Eastern Ghats Province is part of a series of terranes that collectively form the Eastern Ghats in India. The Eastern Ghats is a Mesoproterozoic to early Neoproterozoic orogen associated with the formation of the supercontinent Rodinia, c. 1.1 to 0.95 Ga. The central Eastern Ghats Province consists of metaquartzites and metapelites (khondalites) that are intruded by granitoids. The location of proto-India within Rodinia is disputed because of recently presented palaeomagnetic data. This has generated confusion about whether the protoliths to the Eastern Ghats Province metasedimentary rocks were deposited adjacent to proto-India or as an exotic terrane later accreted to India. U-Pb geochronology, in conjunction with Hf isotopes of zircons, constrain the maximum depositional age, determine provenance and identify the location of deposition. A maximum depositional age of 1.14 Ga on the protoliths to the khondalites has been determined from U-Pb zircon geochronology. The short period of time between deposition and the orogenesis related thermal event indicates that the sediments were deposited adjacent to the Bastar Craton. Provenance work identifies a number of sources within India and east Antarctica lending support to the theory that these continents were contiguous prior to the Eastern Ghats Orogeny. Structural transects and mapping reveals that shortening associated with the collision of east Antarctica and proto-India occurred along a NE-SW trending axis.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2010