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Eduardo Garzanti - One of the best experts on this subject based on the ideXlab platform.
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The Himalayan Foreland Basin from collision onset to the present: a Sedimentary–Petrology perspective
Geological Society London Special Publications, 2019Co-Authors: Eduardo GarzantiAbstract:AbstractThis chapter summarizes the available stratigraphic, petrographical and mineralogical evidence from sediments and Sedimentary rocks on the evolution of the Himalayan belt and its associated foreland basin. The use of compositional signatures of modern sediments to unravel provenance changes and palaeodrainage evolution through time is hampered by a poor match with detrital modes of ancient strata markedly affected by selective chemical dissolution of unstable minerals during diagenesis. Only semi-quantitative diagnoses can thus be attempted. Volcanic detritus derived from Transhimalayan arcs since India–Asia collision onset at c. 60 Ma was deposited onto the Indian lower plate throughout the Protohimalayan stage, with the exception of the Tansen region of Nepal that is characterized by quartz-arenites yielding orogen-derived zircon grains. During the Eohimalayan stage, begun in the late Eocene when most sedimentation ceased in the Tethys Himalayan domain, low-rank metaSedimentary detritus was overwhelming in the central foreland basin, where a widespread unconformity developed spanning locally as much as 20 myr. Volcanic detritus from Transhimalayan arcs remained significant in northern Pakistan. Arrival of higher-rank metamorphic detritus since the earliest Miocene, and the successive occurrence of garnet, staurolite, kyanite and finally sillimanite, characterized the Neohimalayan stage, when repeated compositional changes in the foreland-basin succession document the stepwise propagation of crustal deformation across the Indian Plate margin and widening of the thrust belt with exhumation of progressively more external tectonic units. The correspondence in time between the activity of major thrusts and petrofacies changes indicates a promising approach to accurately reconstruct the geological evolution of the coupled orogen–basin system. Conversely, a poor conceptual framework and the general reliance on ad hoc mechanisms to explain phenomena unpredicted by simplified models represent major factors limiting the robustness of palaeotectonic interpretations. Improved knowledge requires taking into full account the dynamic role played by still poorly understood subduction processes – rather than exclusively the effect of passive loading – as well as the role played by the presence of inherited structures on the downgoing Indian Plate, which control both lateral variability of orogenic deformation and the location of depocentres in the foreland basin.
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from static to dynamic provenance analysis Sedimentary Petrology upgraded
Sedimentary Geology, 2016Co-Authors: Eduardo GarzantiAbstract:Abstract The classical approach to sandstone Petrology, established in the golden years of plate tectonics and based on the axiom that “detrital modes of sandstone suites primarily reflect the different tectonic settings of provenance terranes,” has represented a benchmark for decades. The composition of sand and sandstone, however, simply provides us with a distorted image of the lithological structure of source terranes and gives us little clue whether they are allochthonous or autochthonous, orogenic or anorogenic, young or old. What we may able to see reflected in detrital modes is the nature of source terranes (continental, arc, oceanic) and the tectonostratigraphic level reached by erosion in space and time. The proposed new approach to the Petrology of sand and sandstone (1) starts with a simple classification scheme circulated since the 1960s, which is purely descriptive, objective, and free of ill-defined ambiguous terms and (2) focuses on the nature and tectonostratigraphic level of source terranes. Further steps are essential to upgrade provenance analysis. Acquiring knowledge from modern settings is needed to properly identify and wherever possible correct for physical and chemical processes introducing environmental and diagenetic bias and thus address nature's complexities with adequate conceptual tools. Equally important is the integration of multiple techniques, ideally including bulk-sediment, multi-mineral, and single-mineral methods. Bulk-sediment petrography remains the fundamental approach that allows us to capture the most precious source of direct provenance information, represented by the mineralogy and texture of rock fragments. Bulk-sediment geochemistry, applicable also to silt and clay carried in suspension, is a superior method to check for hydraulic sorting, chemical weathering, and fertility of detrital minerals in different sediment sources. Detrital geochronology, thermochronology, and isotope geochemistry reveal the diverse time structures of source rocks and have become necessary complementary techniques in modern provenance analysis. Inferences on geodynamic processes need independent geological information and come last, but if tackled properly, they can lead us much farther than the standard label obtained by using triangular diagrams uncritically as if they were infallible oracles.
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From static to dynamic provenance analysis—Sedimentary Petrology upgraded
Sedimentary Geology, 2016Co-Authors: Eduardo GarzantiAbstract:Abstract The classical approach to sandstone Petrology, established in the golden years of plate tectonics and based on the axiom that “detrital modes of sandstone suites primarily reflect the different tectonic settings of provenance terranes,” has represented a benchmark for decades. The composition of sand and sandstone, however, simply provides us with a distorted image of the lithological structure of source terranes and gives us little clue whether they are allochthonous or autochthonous, orogenic or anorogenic, young or old. What we may able to see reflected in detrital modes is the nature of source terranes (continental, arc, oceanic) and the tectonostratigraphic level reached by erosion in space and time. The proposed new approach to the Petrology of sand and sandstone (1) starts with a simple classification scheme circulated since the 1960s, which is purely descriptive, objective, and free of ill-defined ambiguous terms and (2) focuses on the nature and tectonostratigraphic level of source terranes. Further steps are essential to upgrade provenance analysis. Acquiring knowledge from modern settings is needed to properly identify and wherever possible correct for physical and chemical processes introducing environmental and diagenetic bias and thus address nature's complexities with adequate conceptual tools. Equally important is the integration of multiple techniques, ideally including bulk-sediment, multi-mineral, and single-mineral methods. Bulk-sediment petrography remains the fundamental approach that allows us to capture the most precious source of direct provenance information, represented by the mineralogy and texture of rock fragments. Bulk-sediment geochemistry, applicable also to silt and clay carried in suspension, is a superior method to check for hydraulic sorting, chemical weathering, and fertility of detrital minerals in different sediment sources. Detrital geochronology, thermochronology, and isotope geochemistry reveal the diverse time structures of source rocks and have become necessary complementary techniques in modern provenance analysis. Inferences on geodynamic processes need independent geological information and come last, but if tackled properly, they can lead us much farther than the standard label obtained by using triangular diagrams uncritically as if they were infallible oracles.
Yoshiki Fujiwara - One of the best experts on this subject based on the ideXlab platform.
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Sedimentary Petrology and paleotectonic analysis of the arc arc junction the paleocene nakanogawa group in the hidaka belt central hokkaido japan
Palaeogeography Palaeoclimatology Palaeoecology, 1993Co-Authors: Futoshi Nanayama, T. Kanamatsu, Yoshiki FujiwaraAbstract:Abstract Two arc-trench systems have been recognized by using paleomagnetic data in the Hokkaido Central Belt, northeast Japan, during Late Cretaceous to Early Paleogene: the Paleo-Japan and the Paleo-Kuril arc-trench systems. The Hidaka Belt is composed mainly of Paleocene turbidite facies, with a small amount of hemipelagic sediment and melange facies. These sediments accumulated near the trench area, later composed accretionary bodies in the two arc-trench systems. The Nakanogawa Group is typically exposed on the southern side of the Hidaka Belt. This group is divided into three petroprovinces; zones I–III, from south to north on the basis of Sedimentary, petrological and paleocurrent analyses. The modal component of sandstones from zone I indicate that they are characteristically rich in volcanic rock fragments (intermediate to basic composition), clinopyroxene, hornblende and poor in quartz. The characteristics of zone I are similar to those of forearc to slope basin sediments in the Paleo-Kuril arc-trench system. The modal component of sandstones from zone III consists predominantly of monocrystalline quartz, K-feldspar, acidic volcanic fragments, radiolarian chert and tectonite fragments, similar to those of forearc basin sediments of the Paleo-Japan arc-trench system. The modal component of rocks from zone II are regarded as being intermediate between zones I and III. However, clinopyroxene and chromian spinel chemical data suggest that the sandstones of zones I and II were derived from the Paleo-Kuril arc region. The sediments of the Hidaka Belt were thus derived from two different arc-trench systems and deposited in the arc—arc junction area during the Paleocene.
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Sedimentary Petrology and paleotectonic analysis of the arc—arc junction: the Paleocene Nakanogawa Group in the Hidaka Belt, central Hokkaido, Japan
Palaeogeography Palaeoclimatology Palaeoecology, 1993Co-Authors: Futoshi Nanayama, T. Kanamatsu, Yoshiki FujiwaraAbstract:Abstract Two arc-trench systems have been recognized by using paleomagnetic data in the Hokkaido Central Belt, northeast Japan, during Late Cretaceous to Early Paleogene: the Paleo-Japan and the Paleo-Kuril arc-trench systems. The Hidaka Belt is composed mainly of Paleocene turbidite facies, with a small amount of hemipelagic sediment and melange facies. These sediments accumulated near the trench area, later composed accretionary bodies in the two arc-trench systems. The Nakanogawa Group is typically exposed on the southern side of the Hidaka Belt. This group is divided into three petroprovinces; zones I–III, from south to north on the basis of Sedimentary, petrological and paleocurrent analyses. The modal component of sandstones from zone I indicate that they are characteristically rich in volcanic rock fragments (intermediate to basic composition), clinopyroxene, hornblende and poor in quartz. The characteristics of zone I are similar to those of forearc to slope basin sediments in the Paleo-Kuril arc-trench system. The modal component of sandstones from zone III consists predominantly of monocrystalline quartz, K-feldspar, acidic volcanic fragments, radiolarian chert and tectonite fragments, similar to those of forearc basin sediments of the Paleo-Japan arc-trench system. The modal component of rocks from zone II are regarded as being intermediate between zones I and III. However, clinopyroxene and chromian spinel chemical data suggest that the sandstones of zones I and II were derived from the Paleo-Kuril arc region. The sediments of the Hidaka Belt were thus derived from two different arc-trench systems and deposited in the arc—arc junction area during the Paleocene.
Gert Jan Weltje - One of the best experts on this subject based on the ideXlab platform.
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quantitative analysis of detrital modes statistically rigorous confidence regions in ternary diagrams and their use in Sedimentary Petrology
Earth-Science Reviews, 2002Co-Authors: Gert Jan WeltjeAbstract:Abstract Detrital modes are the basic type of quantitative data used in Sedimentary Petrology. They represent estimates of the petrographic framework composition of sand or sandstone obtained by point counting of thin sections. At present, geological inferences from analysis of these numerical data are semi-quantitative only, because many of the data-processing methods employed in Sedimentary Petrology lack a firm theoretical basis. A review of existing methods reveals a number of fundamental statistical problems associated with the use of univariate statistics and the construction of so-called hexagonal fields of compositional variation. It is shown that these problems can be overcome by using multivariate methods that honour the non-negativity and unit-sum constraints on compositional data, and incorporate the covariance structure. Spread in compositional data can be modelled on two levels: (1) by regarding the grain as unit of observation, and the total point count as a sample from a multinomial distribution; (2) by regarding the total count as unit of observation, and a set of counts as a sample from an additive logistic normal distribution. Numerical methods are presented for constructing statistically rigorous confidence regions in ternary diagrams by inversion of significance tests for these two distributions. Statistical analyses of the framework composition and heavy-mineral assemblages of modern beach and river sands illustrate their use. The case histories are followed by a brief overview of popular multivariate methods for reconstructing sediment provenance.
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Quantitative analysis of detrital modes: statistically rigorous confidence regions in ternary diagrams and their use in Sedimentary Petrology
Earth-Science Reviews, 2002Co-Authors: Gert Jan WeltjeAbstract:status: publishe
Futoshi Nanayama - One of the best experts on this subject based on the ideXlab platform.
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Sedimentary Petrology and paleotectonic analysis of the arc arc junction the paleocene nakanogawa group in the hidaka belt central hokkaido japan
Palaeogeography Palaeoclimatology Palaeoecology, 1993Co-Authors: Futoshi Nanayama, T. Kanamatsu, Yoshiki FujiwaraAbstract:Abstract Two arc-trench systems have been recognized by using paleomagnetic data in the Hokkaido Central Belt, northeast Japan, during Late Cretaceous to Early Paleogene: the Paleo-Japan and the Paleo-Kuril arc-trench systems. The Hidaka Belt is composed mainly of Paleocene turbidite facies, with a small amount of hemipelagic sediment and melange facies. These sediments accumulated near the trench area, later composed accretionary bodies in the two arc-trench systems. The Nakanogawa Group is typically exposed on the southern side of the Hidaka Belt. This group is divided into three petroprovinces; zones I–III, from south to north on the basis of Sedimentary, petrological and paleocurrent analyses. The modal component of sandstones from zone I indicate that they are characteristically rich in volcanic rock fragments (intermediate to basic composition), clinopyroxene, hornblende and poor in quartz. The characteristics of zone I are similar to those of forearc to slope basin sediments in the Paleo-Kuril arc-trench system. The modal component of sandstones from zone III consists predominantly of monocrystalline quartz, K-feldspar, acidic volcanic fragments, radiolarian chert and tectonite fragments, similar to those of forearc basin sediments of the Paleo-Japan arc-trench system. The modal component of rocks from zone II are regarded as being intermediate between zones I and III. However, clinopyroxene and chromian spinel chemical data suggest that the sandstones of zones I and II were derived from the Paleo-Kuril arc region. The sediments of the Hidaka Belt were thus derived from two different arc-trench systems and deposited in the arc—arc junction area during the Paleocene.
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Sedimentary Petrology and paleotectonic analysis of the arc—arc junction: the Paleocene Nakanogawa Group in the Hidaka Belt, central Hokkaido, Japan
Palaeogeography Palaeoclimatology Palaeoecology, 1993Co-Authors: Futoshi Nanayama, T. Kanamatsu, Yoshiki FujiwaraAbstract:Abstract Two arc-trench systems have been recognized by using paleomagnetic data in the Hokkaido Central Belt, northeast Japan, during Late Cretaceous to Early Paleogene: the Paleo-Japan and the Paleo-Kuril arc-trench systems. The Hidaka Belt is composed mainly of Paleocene turbidite facies, with a small amount of hemipelagic sediment and melange facies. These sediments accumulated near the trench area, later composed accretionary bodies in the two arc-trench systems. The Nakanogawa Group is typically exposed on the southern side of the Hidaka Belt. This group is divided into three petroprovinces; zones I–III, from south to north on the basis of Sedimentary, petrological and paleocurrent analyses. The modal component of sandstones from zone I indicate that they are characteristically rich in volcanic rock fragments (intermediate to basic composition), clinopyroxene, hornblende and poor in quartz. The characteristics of zone I are similar to those of forearc to slope basin sediments in the Paleo-Kuril arc-trench system. The modal component of sandstones from zone III consists predominantly of monocrystalline quartz, K-feldspar, acidic volcanic fragments, radiolarian chert and tectonite fragments, similar to those of forearc basin sediments of the Paleo-Japan arc-trench system. The modal component of rocks from zone II are regarded as being intermediate between zones I and III. However, clinopyroxene and chromian spinel chemical data suggest that the sandstones of zones I and II were derived from the Paleo-Kuril arc region. The sediments of the Hidaka Belt were thus derived from two different arc-trench systems and deposited in the arc—arc junction area during the Paleocene.
T. Kanamatsu - One of the best experts on this subject based on the ideXlab platform.
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Sedimentary Petrology and paleotectonic analysis of the arc arc junction the paleocene nakanogawa group in the hidaka belt central hokkaido japan
Palaeogeography Palaeoclimatology Palaeoecology, 1993Co-Authors: Futoshi Nanayama, T. Kanamatsu, Yoshiki FujiwaraAbstract:Abstract Two arc-trench systems have been recognized by using paleomagnetic data in the Hokkaido Central Belt, northeast Japan, during Late Cretaceous to Early Paleogene: the Paleo-Japan and the Paleo-Kuril arc-trench systems. The Hidaka Belt is composed mainly of Paleocene turbidite facies, with a small amount of hemipelagic sediment and melange facies. These sediments accumulated near the trench area, later composed accretionary bodies in the two arc-trench systems. The Nakanogawa Group is typically exposed on the southern side of the Hidaka Belt. This group is divided into three petroprovinces; zones I–III, from south to north on the basis of Sedimentary, petrological and paleocurrent analyses. The modal component of sandstones from zone I indicate that they are characteristically rich in volcanic rock fragments (intermediate to basic composition), clinopyroxene, hornblende and poor in quartz. The characteristics of zone I are similar to those of forearc to slope basin sediments in the Paleo-Kuril arc-trench system. The modal component of sandstones from zone III consists predominantly of monocrystalline quartz, K-feldspar, acidic volcanic fragments, radiolarian chert and tectonite fragments, similar to those of forearc basin sediments of the Paleo-Japan arc-trench system. The modal component of rocks from zone II are regarded as being intermediate between zones I and III. However, clinopyroxene and chromian spinel chemical data suggest that the sandstones of zones I and II were derived from the Paleo-Kuril arc region. The sediments of the Hidaka Belt were thus derived from two different arc-trench systems and deposited in the arc—arc junction area during the Paleocene.
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Sedimentary Petrology and paleotectonic analysis of the arc—arc junction: the Paleocene Nakanogawa Group in the Hidaka Belt, central Hokkaido, Japan
Palaeogeography Palaeoclimatology Palaeoecology, 1993Co-Authors: Futoshi Nanayama, T. Kanamatsu, Yoshiki FujiwaraAbstract:Abstract Two arc-trench systems have been recognized by using paleomagnetic data in the Hokkaido Central Belt, northeast Japan, during Late Cretaceous to Early Paleogene: the Paleo-Japan and the Paleo-Kuril arc-trench systems. The Hidaka Belt is composed mainly of Paleocene turbidite facies, with a small amount of hemipelagic sediment and melange facies. These sediments accumulated near the trench area, later composed accretionary bodies in the two arc-trench systems. The Nakanogawa Group is typically exposed on the southern side of the Hidaka Belt. This group is divided into three petroprovinces; zones I–III, from south to north on the basis of Sedimentary, petrological and paleocurrent analyses. The modal component of sandstones from zone I indicate that they are characteristically rich in volcanic rock fragments (intermediate to basic composition), clinopyroxene, hornblende and poor in quartz. The characteristics of zone I are similar to those of forearc to slope basin sediments in the Paleo-Kuril arc-trench system. The modal component of sandstones from zone III consists predominantly of monocrystalline quartz, K-feldspar, acidic volcanic fragments, radiolarian chert and tectonite fragments, similar to those of forearc basin sediments of the Paleo-Japan arc-trench system. The modal component of rocks from zone II are regarded as being intermediate between zones I and III. However, clinopyroxene and chromian spinel chemical data suggest that the sandstones of zones I and II were derived from the Paleo-Kuril arc region. The sediments of the Hidaka Belt were thus derived from two different arc-trench systems and deposited in the arc—arc junction area during the Paleocene.