Bassis, Alexander (2017)
Petrography, geochemistry and provenance of Saudi Arabian
Palaeozoic sandstones.
Technische Universität Darmstadt
Dissertation, Erstveröffentlichung
Kurzbeschreibung (Abstract)
The Arabian Peninsula hosts a thick Palaeozoic succession, ranging from the Cambrian through the Permian. It not only contains deposits of the two major Palaeozoic glaciations, but also holds both the major Palaeozoic hydrocarbon source and reservoir rocks. In addition, Palaeozoic sandstones serve as important aquifers. The succession is dominated by highly mature quartz arenites, as seen in thin sections. It is starved of fossils and very uniform in lithology. This creates unique problems for the interpretation of provenance and tectonic setting as well as for stratigraphic correlations. In order to better understand provenance, tectonic setting and stratigraphic relationships, the petrography, major and trace element geochemistry, heavy mineral assemblages and single-grain geochemistry of sandstones were studied. Samples were taken in several field campaigns from two study areas in southern (Wajid area) as well as central and northern (Tabuk area) Saudi Arabia. The data set presented here is the first comprehensive study to cover the entire Palaeozoic succession in both the southern and northern part of the Arabian Peninsula. Tectonic discrimination diagrams suggest that deposition of sandstones took place in an intracratonic setting, which is in accordance with the established model for the evolution of the Arabian Plate. The collisional signal from some samples is a relic from the last stages of the amalgamation of Gondwana, carried into the basin by glaciogenic sediments. Major and trace element geochemistry indicate the Neoproterozoic basement of the nearby Arabian Shield as the most likely source for the detritus. An influx of fresh material, probably sourced from the Shield, did occur in the upper Palaeozoic units of southern Saudi Arabia but did not reach the northern study area. Petrographic and geochemical observations have proven to be unsuitable to assess the influence of sedimentary recycling versus strong weathering and reworking during deposition in highly mature quartz arenites. A (meta-) sedimentary source for the Palaeozoic sandstones could therefore neither be proven nor refuted. Multivariate cluster and principal component analysis of geochemical data revealed significant differences between the two study areas. They further allowed differentiating between the lower and upper parts of the southern Saudi Arabian Palaeozoic succession. The heavy mineral assemblages reflect the mineralogical maturity of the Saudi Arabian Palaeozoic siliciclastics. They are dominated by the ultra-stable phases zircon, tourmaline and rutile. Less stable accessories are apatite, staurolite and garnet. Standard heavy mineral analysis of samples from both study areas reveals distinct changes in provenance. Cambrian–Ordovician sandstones are first-cycle sediments, probably sourced from the Arabian-Nubian Shield. The overlying, Hirnantian glaciogenic deposits consist of recycled Cambrian–Ordovician material. Devonian–Permian sandstones show a significant influx of fresh basement material, as attested by an increase of meta-stable heavy minerals. Single-grain geochemical analysis of rutile and garnet has proven to be a powerful supplementary technique. Rutile varietal studies reveal distinct differences in host rock lithologies between the two study areas. Zr-in-rutile thermometry identified granulite-facies detritus in the lower Palaeozoic of the Tabuk area and has the potential to further define source areas. The distribution patterns of garnet host rock lithologies are remarkably similar in both study areas. They are dominated by amphibolite-facies metasediments and intermediate to felsic igneous rocks. Garnets derived from granulite-facies metasediments, which are scarce in the Arabian-Nubian Shield, also occur. Possible source rocks for high-grade garnets can be found in Yemen or further south in the Mozambique Belt. A closer look was taken at the Khida Terrane – a block of old continental crust situated at the southeastern margin of the Arabian Shield. The Khida Terrane contains various Palaeo- to Neoproterozoic igneous suites as well as metasedimentary successions and is a potential source area for Palaeozoic sediments. Geochemical analyses revealed a collisional setting of most igneous samples. Petrographical observations showed the presence of primary igneous garnet and zinnwaldite mica in one igneous sample and significant amounts of Cr-spinel in a metasediment.
Typ des Eintrags: | Dissertation | ||||
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Erschienen: | 2017 | ||||
Autor(en): | Bassis, Alexander | ||||
Art des Eintrags: | Erstveröffentlichung | ||||
Titel: | Petrography, geochemistry and provenance of Saudi Arabian Palaeozoic sandstones | ||||
Sprache: | Englisch | ||||
Referenten: | Hinderer, Prof. Dr. Matthias ; Schüth, Prof. Dr. Christoph ; Henk, Prof. Dr. Andreas ; Becker, Prof. Dr. Matthias | ||||
Publikationsjahr: | 2017 | ||||
Ort: | Darmstadt | ||||
Datum der mündlichen Prüfung: | 18 April 2017 | ||||
URL / URN: | http://tuprints.ulb.tu-darmstadt.de/6246 | ||||
Kurzbeschreibung (Abstract): | The Arabian Peninsula hosts a thick Palaeozoic succession, ranging from the Cambrian through the Permian. It not only contains deposits of the two major Palaeozoic glaciations, but also holds both the major Palaeozoic hydrocarbon source and reservoir rocks. In addition, Palaeozoic sandstones serve as important aquifers. The succession is dominated by highly mature quartz arenites, as seen in thin sections. It is starved of fossils and very uniform in lithology. This creates unique problems for the interpretation of provenance and tectonic setting as well as for stratigraphic correlations. In order to better understand provenance, tectonic setting and stratigraphic relationships, the petrography, major and trace element geochemistry, heavy mineral assemblages and single-grain geochemistry of sandstones were studied. Samples were taken in several field campaigns from two study areas in southern (Wajid area) as well as central and northern (Tabuk area) Saudi Arabia. The data set presented here is the first comprehensive study to cover the entire Palaeozoic succession in both the southern and northern part of the Arabian Peninsula. Tectonic discrimination diagrams suggest that deposition of sandstones took place in an intracratonic setting, which is in accordance with the established model for the evolution of the Arabian Plate. The collisional signal from some samples is a relic from the last stages of the amalgamation of Gondwana, carried into the basin by glaciogenic sediments. Major and trace element geochemistry indicate the Neoproterozoic basement of the nearby Arabian Shield as the most likely source for the detritus. An influx of fresh material, probably sourced from the Shield, did occur in the upper Palaeozoic units of southern Saudi Arabia but did not reach the northern study area. Petrographic and geochemical observations have proven to be unsuitable to assess the influence of sedimentary recycling versus strong weathering and reworking during deposition in highly mature quartz arenites. A (meta-) sedimentary source for the Palaeozoic sandstones could therefore neither be proven nor refuted. Multivariate cluster and principal component analysis of geochemical data revealed significant differences between the two study areas. They further allowed differentiating between the lower and upper parts of the southern Saudi Arabian Palaeozoic succession. The heavy mineral assemblages reflect the mineralogical maturity of the Saudi Arabian Palaeozoic siliciclastics. They are dominated by the ultra-stable phases zircon, tourmaline and rutile. Less stable accessories are apatite, staurolite and garnet. Standard heavy mineral analysis of samples from both study areas reveals distinct changes in provenance. Cambrian–Ordovician sandstones are first-cycle sediments, probably sourced from the Arabian-Nubian Shield. The overlying, Hirnantian glaciogenic deposits consist of recycled Cambrian–Ordovician material. Devonian–Permian sandstones show a significant influx of fresh basement material, as attested by an increase of meta-stable heavy minerals. Single-grain geochemical analysis of rutile and garnet has proven to be a powerful supplementary technique. Rutile varietal studies reveal distinct differences in host rock lithologies between the two study areas. Zr-in-rutile thermometry identified granulite-facies detritus in the lower Palaeozoic of the Tabuk area and has the potential to further define source areas. The distribution patterns of garnet host rock lithologies are remarkably similar in both study areas. They are dominated by amphibolite-facies metasediments and intermediate to felsic igneous rocks. Garnets derived from granulite-facies metasediments, which are scarce in the Arabian-Nubian Shield, also occur. Possible source rocks for high-grade garnets can be found in Yemen or further south in the Mozambique Belt. A closer look was taken at the Khida Terrane – a block of old continental crust situated at the southeastern margin of the Arabian Shield. The Khida Terrane contains various Palaeo- to Neoproterozoic igneous suites as well as metasedimentary successions and is a potential source area for Palaeozoic sediments. Geochemical analyses revealed a collisional setting of most igneous samples. Petrographical observations showed the presence of primary igneous garnet and zinnwaldite mica in one igneous sample and significant amounts of Cr-spinel in a metasediment. |
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URN: | urn:nbn:de:tuda-tuprints-62467 | ||||
Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften | ||||
Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Geowissenschaften > Fachgebiet Angewandte Sedimentgeologie 11 Fachbereich Material- und Geowissenschaften > Geowissenschaften 11 Fachbereich Material- und Geowissenschaften |
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Hinterlegungsdatum: | 04 Jun 2017 19:55 | ||||
Letzte Änderung: | 04 Jun 2017 19:55 | ||||
PPN: | |||||
Referenten: | Hinderer, Prof. Dr. Matthias ; Schüth, Prof. Dr. Christoph ; Henk, Prof. Dr. Andreas ; Becker, Prof. Dr. Matthias | ||||
Datum der mündlichen Prüfung / Verteidigung / mdl. Prüfung: | 18 April 2017 | ||||
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