scholarly journals About this title - Archean Granitoids of India: Windows into Early Earth Tectonics

10.1144/sp489 ◽  
2020 ◽  
Vol 489 (1) ◽  
pp. NP-NP
Author(s):  
S. Dey ◽  
J.-F. Moyen
Keyword(s):  
Tectonic Setting ◽  
Temporal Distribution ◽  
Early Earth ◽  
Crustal Evolution ◽  
Reference Information ◽  
Geodynamic Processes ◽  
Emplacement Mechanism ◽  
Available Information ◽  
Metal Delivery ◽  
Granite Petrology

Granitoids form the bulk of the Archean continental crust and preserve key information on early Earth evolution. India hosts five main Archean cratonic blocks (Aravalli, Bundelkhand, Singhbhum, Bastar and Dharwar). This book summarizes the available information on Archean granitoids of Indian cratons. The chapters cover a broad spectrum of themes related to granitoid typology, emplacement mechanism, petrogenesis, phase-equilibria modelling, temporal distribution, tectonic setting, and their roles in fluid evolution, metal delivery and mineralizations. The book presents a broader picture incorporating regional- to cratons-scale comparisons, implications for Archean geodynamic processes, and temporal changes thereof. This synthesis work, integrating modern concepts on granite petrology and crustal evolution, offers an irreplaceable body of reference information for any geologist interested in Archean Indian granitoids.

scholarly journals The Morrison Formation sauropod consensus: A freely accessible online spreadsheet of collected sauropod specimens, their housing institutions, contents, references, localities, and other potentially useful information

2019 ◽  
Author(s):  
Emanuel Tschopp ◽  
John A. Whitlock ◽  
D. Cary Woodruff ◽  
John R. Foster ◽  
Roberto Lei ◽  
...  
Keyword(s):  
Temporal Distribution ◽  
The United States ◽  
Quality Data ◽  
Morrison Formation ◽  
High Quality Data ◽  
Museum Exhibits ◽  
3D Scans ◽  
Available Information ◽  
Sheer Number

The Morrison Formation has been explored for dinosaurs for more than 150 years, in particular for large sauropod skeletons to be mounted in museum exhibits around the world. Several long-term campaigns to the Jurassic West of the United States produced hundreds of specimens, ranging from isolated, fragmentary bones to nearly complete skeletons of these enormous herbivorous animals. Given the sheer number of specimens, keeping track of what is housed in which institution is paramount to study variability, taxonomy, and consequently geographic and temporal distribution of the various species and genera recognized from the Morrison Formation. In an attempt to facilitate these studies, we have compiled an online spreadsheet intended to combine all the available information on sauropod specimens from collection databases, published literature, and personal observations. These include lists of contents of the specimens, in what institution the material is housed, references mentioning, describing, figuring, providing measurements and/or 3D scans, locality data and stratigraphy, as well as other potentially useful data for research purposes. The spreadsheet is openly accessible, but editing is currently restricted to the authors of this study, in order to ensure high-quality data curation to keep the file as useful as possible.

Subsidence discrepancy in the Valencia Trough revealed from reflection seismic observations and backstripping results

2020 ◽  
Author(s):  
Penggao Fang ◽  
Geoffroy Mohn ◽  
Julie Tugend ◽  
Nick Kusznir
Keyword(s):  
Tectonic Setting ◽  
Temporal Distribution ◽  
Drill Hole ◽  
Western Mediterranean ◽  
Normal Faults ◽  
Seismic Profiles ◽  
Gulf Of Lions ◽  
North West ◽  
The North ◽  
Valencia Trough

<p>    The Valencia Trough is commonly included as part of the set of western Mediterranean Cenozoic extensional basins that formed in relation with the Tethyan oceanic slab rollback during the latest Oligocene to early Miocene. It lies in a complex tectonic setting between the Gulf of Lions to the North-West, the Catalan Coastal Range and the Iberian chain to the West, the Balearic promontory to the East and the Betic orogenic system to the South. This rifting period is coeval with or directly followed by the development of the external Betics fold and thrust belts at the southern tip of the Valencia Trough. Recent investigations suggest that the Valencia Trough is segmented into two main domains exhibiting different geological and geophysical characteristics between its northeastern and southwestern parts. The presence of numerous Cenozoic normal faults and the well-studied subsidence pattern evolution of the NE part of the Valencia Trough suggest that it mainly formed coevally with the rifting of Gulf of Lion. However, if a significant post-Oligocene subsidence is also evidenced in its SW part; fewer Cenozoic rift structures are observed suggesting that the subsidence pattern likely results from the interference of different processes.</p><p>    In this presentation, we quantify the post-Oligocene subsidence history of the SW part of the Valencia Trough with the aim of evaluating the potential mechanisms explaining this apparent subsidence discrepancy. We analyzed the spatial and temporal distribution of the post-Oligocene subsidence using the interpretation of a dense grid of high-quality multi-channel seismic profiles, also integrating drill-hole results and velocity information from expanding spread profiles (ESP). We used the mapping of the main unconformities, especially the so-called Oligocene unconformity, to perform a 3D flexural backstripping, which permits the prediction of the post-Oligocene water-loaded subsidence. Our results confirm that the post-Oligocene subsidence of the SW part of the Valencia Trough cannot be explained by the rifting of the Gulf of Lions. Previous works already showed that the extreme crustal thinning observed to the SW is related to a previous Mesozoic rift event. Here, we further highlight that if few Cenozoic extensional structures are observed, they can be interpreted as gravitational features rooting at the regionally identified Upper Triassic evaporite level. Backstripping results combined with the mapping of the first sediments deposited on top of the Oligocene unconformity show that they are largely controlled by the shape of Betic front with a possible additional effect of preserved Mesozoic structures. At larger scale, we compare the mechanisms accounting for the origin and subsidence at the SW part of the Valencia Trough with those responsible for the subsidence of its NE part and the Gulf of Lions.</p>

scholarly journals The Morrison Formation Sauropod Consensus: A freely accessible online spreadsheet of collected sauropod specimens, their housing institutions, contents, references, localities, and other potentially useful information

2019 ◽  
Author(s):  
Emanuel Tschopp ◽  
John A. Whitlock ◽  
D. Cary Woodruff ◽  
John R. Foster ◽  
Roberto Lei ◽  
...  
Keyword(s):  
Temporal Distribution ◽  
The United States ◽  
Quality Data ◽  
Morrison Formation ◽  
High Quality Data ◽  
Museum Exhibits ◽  
3D Scans ◽  
Available Information ◽  
Sheer Number

The Morrison Formation has been explored for dinosaurs for more than 150 years, often specifically for large sauropod skeletons curators wanted to mount as attractions in their museum exhibits around the world. Several long-term campaigns to the Jurassic West of the United States produced hundreds of specimens, ranging from isolated, fragmentary bones to nearly complete skeletons of these enormous herbivorous animals. Given the sheer number of specimens, keeping track of what is housed in which institution is paramount to study variability, taxonomy, and consequently geographic and temporal distribution of the various species and genera recognized from the Morrison Formation. In an attempt to facilitate these studies, we have compiled an online spreadsheet intended to combine all the available information on sauropod specimens from collection databases, published literature, and personal observations. These include lists of contents of the specimens, in what institution the material is housed, references mentioning, describing, figuring, providing measurements and/or 3D scans, locality data and stratigraphy, as well as other potentially useful data for research purposes. The spreadsheet is openly accessible, but editing is currently restricted to the authors of this study, in order to ensure high-quality data curation to keep the file as useful as possible.

scholarly journals Reappraisal of Heat Flow Variations in Mainland Africa

2021 ◽  
Vol 4 (1) ◽  
pp. 26-78
Author(s):  
Jorge Luiz dos Santos Gomes ◽  
Fábio Pinto Vieira ◽  
Valiya Mannathal Hamza
Keyword(s):  
Heat Flow ◽  
Heat Budget ◽  
Tectonic Setting ◽  
High Heat ◽  
Data Sets ◽  
Resource Base ◽  
Geothermal Resources ◽  
The North ◽  
Vertical Distributions ◽  
Available Information

A reappraisal of geothermal data of the mainland of Africa has been carried out based on data sets available at the IHFC website, incremented with updated information on volcanic activities of post Holocene times. Our compilation makes use of 1480 heat flow values that include 1327 observational data supplemented with 36 estimates derived from heat flow-age relation. In addition, the method of magmatic heat budget (MHB) has been employed in deriving deep crustal heat flow values for 117 for sites of recent volcanic activity, most of it located in Ethiopia. These data sets were regrouped into regular equal-area cells with dimensions of 5 x 5 degrees and subsequently employed in deriving maps of the regional distributions of heat flow and geothermal resources and interpreted on the basis of available information on tectonic setting and geological characteristics. The most prominent features are the relatively high values in the region of rift valleys in the eastern sector of the continent. High heat flow values also occur along north-south trending belts of Atlas Mountains in the north and pockets associated with the Cameroon volcanic chain on the west-central parts of the continent. The vertical distributions of temperatures were calculated for depths reaching down to 6 km. The associated resource base calculations indicate availability of high temperature resources in vast regions of the African continent.

scholarly journals Emplacement mechanism of Late Triassic granitic Dushan pluton, North China and its tectonic implications

2020 ◽  
Author(s):  
Huabiao Qiu ◽  
Wei Lin ◽  
Yan Chen ◽  
Michel Faure
Keyword(s):  
Solid State ◽  
North China ◽  
Tectonic Setting ◽  
Late Triassic ◽  
Gravity Modeling ◽  
Magnetic Fabrics ◽  
Southeastern Margin ◽  
Emplacement Mechanism ◽  
Southwestern Margin ◽  
Magnetic Lineations

<p>To better understand the Late Triassic tectonic setting in the northern North China Craton (NCC), a multidisciplinary investigation, including structural geology, geochronology, anisotropy of magnetic susceptibility (AMS) and gravity modeling, has been carried out in the Dushan pluton. The Dushan pluton consists of monzogranite and biotite-rich facies along the pluton margin without sharp contact between them. The granite varies southwestwards from isotropic texture to arcuate gneissic structures, with locally mylonitic structures. The intensity of solid-state deformation increases southwestwards across the pluton, leaving preserved magmatic fabrics in the northeastern part. The compatible outward dipping magmatic and solid-state magnetic fabrics, together with mesoscopic fabrics, define an elliptic dome-like pattern with a NE-SW oriented long axis, despite the fabrics dip inwards in the southeastern margin of the pluton. Combining gravity modeling, the Dushan pluton presents an overall tabular or tongue-like shape with a northeastern root. The magnetic lineations nearly strike NE-SW, concordant with the stretching lineations observed in the mylonitic zones. We propose the emplacement mode that the Dushan pluton emplaced southwards through the feeder zone in its northeast, beginning probably with a sill. The later successive magma batches may laterally and upwardly inflate, deform and even recrystallize the former cool-down magma. This inflation forms an arcuate, gneissic to mylonitic foliation in the southwestern margin. The Dushan pluton is considered as typically post-tectonic in emplacement, recording a Late Triassic post-tectonic setting of the northern NCC.</p>

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