Article
Geochemistry & Geophysics
P. Schoettle-Greene, A. R. Duvall, P. D. Crowley
Summary: The Mesozoic and Cenozoic history of Western North America is complex due to terrane accretion, volcanism, and orogenesis. This study focuses on the paleogeographic interpretation of northeastern Oregon and adjacent Idaho by analyzing the distribution of Columbia River Basalt and low-temperature apatite and zircon (U-Th)/He thermochronometry. The results reveal distinct thermal histories associated with unroofing and magmatism, supporting the formation of the Wallowa and Elkhorn Mountains at different times.
Article
Geosciences, Multidisciplinary
Rui Cao, Xinghua Ma, Leon Bagas, Yongbao Gao, Demin Liu, Zailai Mou
Summary: Late Mesozoic igneous intrusions and extensional structures in the SW Fujian region played a significant role in controlling the localization of Fe-polymetallic deposits. Extensional deformation was identified at shallow crustal levels, with normal faults associated with syn-tectonic granites. Geochemical and isotopic evidence suggest a hybrid source for the Tangquan granite, with zircon U-Pb dating indicating crystallization at around 161-159 Ma. The synchronicity of widespread granitic magmatism and polymetallic mineralization in the Late Mesozoic is likely related to extensional tectonics linked to lithospheric thinning.
JOURNAL OF EARTH SCIENCE
(2021)
Article
Geology
Brandon M. Lutz
Summary: At least 75% of gold produced in Oregon comes from the Blue Mountains, mainly from orogenic gold veins and associated placer deposits. The controls on orogenic gold mineralization in the Blue Mountains are not well understood. Through a scale-integrated mineral system, the mobilization, transport, deposition, and exposure of golds are linked to tectonism of Western North American Cordillera. Gold production was estimated from public domain production value and time period, and lode endowment was analyzed based on criteria such as host rocks and vein structure. Argillite, schist, and slate host the majority of gold production, and the striking direction of veins and the paleo-stress field support a margin-parallel shear zone. Dilatant zones and the intersection lines between veins, host rock fabrics, and secondary veins control the locations and characteristics of high-grade ore shoots.
ORE GEOLOGY REVIEWS
(2023)
Article
Geosciences, Multidisciplinary
Changqing Yin, Guochun Zhao, Wenjiao Xiao, Shoufa Lin, Rui Gao, Jian Zhang, Jiahui Qian, Peng Gao, Hengzhong Qiao, Wenxuan Li
Summary: This study summarizes various data including lithostratigraphy, tectonothermal analysis, geochronology, and geophysics to investigate the formation and evolution of the Yinshan Block, the tectonic nature of the Ordos Block, and the subduction to collision history of the Khondalite Belt. New evidence suggests that a magmatic arc developed in the Ordos Block due to northward slab subduction, leading to the formation of a back-arc basin between the Ordos and Yinshan blocks. The collision between the passive-type continental margin of the north margin of the Ordos Block and the Yinshan Block along the Khondalite Belt resulted in the formation of the Western Block. Seismic data indicates the presence of subduction slabs beneath the Ordos Block and the Khondalite Belt, supporting a new tectonic model for the Paleoproterozoic accretion and assembly of the Western Block in North China.
EARTH-SCIENCE REVIEWS
(2023)
Article
Geochemistry & Geophysics
Yao-Hui Jiang, Yun-Chao Liu, Bo-Ning Han, Long Qing, Fo-Guang Du
Summary: The origin and geodynamics of A-type granites in the Pitou complex of southern Jiangxi province, South China were investigated using detailed zircon chronology, Hf isotope, mineral chemistry and whole-rock geochemistry data. The Late Triassic and Early Jurassic A-type granites in the complex show contrasting origins, with the former formed by shallow dehydration melting of early Paleozoic granitoids triggered by intraplating of basaltic magmas and the latter produced by extensive fractionation from gabbroic magmas. The Late Triassic A-type granites were related to the transtension of regional NE-trending strike-slip faults caused by early Indosinian continental collisions, while the Early Jurassic A-type granites were emplaced in a back-arc extensional setting coupled with the slab rollback and subsequent slab break-off of the subducted Palaeo-Pacific plate.
Article
Geosciences, Multidisciplinary
Kathleen D. Surpless, Ryan W. Alford, Calvin Barnes, Aaron Yoshinobu, Natalee E. Weis
Summary: The article investigates the Upper Jurassic Galice Formation in the Western Klamath Mountains and finds that it was deposited between ca. 160 Ma to 151 Ma, overlapping with the Nevadan orogeny. The provenance of the sediment sources for the formation is diverse, including the Sierra Nevada pre-batholithic framework, older Klamath terranes, and possibly the Blue Mountains and Insular superterrane. These findings suggest that the Galice Formation records active Jurassic magmatism in the continental arc, with significant detrital input from continental sediment sources to the east.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2023)
Article
Geology
H. Mvondo, T. Bineli Betsi, Chris R. M. McFarlane, J. Mvondo Ondoa, D. A. Archibald
Summary: The Central Africa Orogenic Belt (CAOB) and its neighboring belts underwent compressional deformation events labeled as D-1 to D-4, which occurred between the Neoproterozoic and Cambrian. Through various analyses, researchers were able to determine the timing of rock formation and the different compressional events in the Yaounde Domain of CAOB. The data also revealed the presence of inherited crust from older periods and provided insights into the tectono-metamorphic and magmatic processes of the region.
INTERNATIONAL GEOLOGY REVIEW
(2023)
Article
Geology
Jingwen Mao, Wei Zheng, Guiqing Xie, Bernd Lehmann, Richard Goldfarb
Summary: Recent exploration in southeast China has led to the discovery of a Middle-Late Jurassic copper belt, consisting of magmatic-hydrothermal copper systems developed along several northeast-trending transpressive fault zones. This copper belt runs parallel to the tin-tungsten province in the Nanling region, located several hundred kilometers inland.
Article
Geochemistry & Geophysics
X. Zeng, Q. Cao, B. Wang, C. Hu, J. X. Tian, J. Zhu, X. Q. Ouyang
Summary: The petroleum system from Jurassic source rocks in Altyn piedmont has been deformed by Yanshan-Himalayan tectonic movement, leading to controversial spatial distribution and sedimentary system studies. Through seismic characterization, sedimentary analysis, and detrital zircon U-Pb dating, the study reveals that the Jurassic formation in Altyn piedmont can be divided into southern, middle, and northern parts, each with different provenances. The active Altyn fault system controls the spatial distribution of the Jurassic formation, making the northern deposition area a crucial target for gas exploration.
Article
Geosciences, Multidisciplinary
Kohei Tominaga, Hidetoshi Hara
Summary: This study investigates LIP activity in the Mesozoic Paleo-Pacific Ocean and presents geochemical and geochronological data for the Mikabu Unit, indicating the presence of oceanic plateau basalts formed during the Late Jurassic. The analysis also suggests these basalts were formed on older oceanic crust of the Izanagi Plate, located thousands of kilometers away from the triple junction, and were later accreted to Asia during the Early Cretaceous.
Article
Geochemistry & Geophysics
Jinbao Su
Summary: The accelerated subduction of the paleo-Pacific Plate resulted in the Late Jurassic uplift of the South China Block and widespread magmatism. The subduction rate and lithospheric viscosity affected mantle flow, overriding plate deformation, and the intrusion of magmas. Low-rate subduction formed a higher angle subduction geometry, while high-rate subduction caused slab break-off. Different subduction rates and lithospheric viscosities influenced mantle flow, overriding plate deformation, and magmatic activity.
Article
Forestry
Kat E. Morici, John D. Bailey
Summary: Fuel reduction treatments in forest ecosystems aim to prevent extreme wildfires, but their effects on woody surface fuels are transitory. Assessing the persistence of changes is crucial for planning future fuel treatments.
Article
Multidisciplinary Sciences
Ahmed Oussou, Peter L. Falkingham, Richard J. Butler, Khadija Boumir, Driss Ouarhache, Kawtar Ech-charay, Andre Charriere, Susannah C. R. Maidment
Summary: In addition to bone fossils, fossil tracks and trackways provide valuable insights into dinosaur paleobiology. This article reports on three new tracksites from the Imilchil area in Morocco, which contain tracks made by different types of dinosaurs, including sauropods, theropods, ornithopods, and potentially bird-like non-avian theropods. The authors also created three-dimensional digital models of the track sites using photogrammetry. These new tracksites contribute to our understanding of dinosaur-substrate interactions and enrich the existing record of faunal ichnoassemblages in the High Atlas Mountains and North Africa.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Geology
Elizabeth M. Bollen, Harold H. Stowell, Margaret E. Rusmore, Glenn J. Woodsworth, M. Robinson Cecil
Summary: Metamorphism in the Mount Waddington area reached high temperatures and pressures, with garnet growth mainly influenced by high-flux magmatism, but the timing of metamorphism and magmatic events differed significantly.
JOURNAL OF METAMORPHIC GEOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Arnob Kumar Mondal, Sankar Bose, J. Amal Dev, J. K. Tomson, Nilanjana Sorcar, Sneha Mukherjee
Summary: Massif type charnockite was emplaced in the lower crust of the Eastern Ghats Province, showing evidence of magmatic emplacement and metamorphism. Geochemical data suggest variable chemistry due to differentiation and crustal contamination.
PRECAMBRIAN RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
B. Ronald Frost, Susan M. Swapp, Carol D. Frost, Davin A. Bagdonas, Kevin R. Chamberlain
Article
Geochemistry & Geophysics
Paul M. Bremner, Mark P. Panning, R. M. Russo, Victor Mocanu, A. Christian Stanciu, Megan Torpey, Sutatcha Hongsresawat, John C. VanDecar, Todd A. LaMaskin, D. A. Foster
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2019)
Article
Geochemistry & Geophysics
Gretchen Hough, Susan Swapp, Carol Frost, Mostafa Fayek
Article
Geosciences, Multidisciplinary
Fabrice Cordey, Frederic Quillevere
GEOLOGICAL MAGAZINE
(2020)
Review
Geosciences, Multidisciplinary
Fabrice Cordey
CANADIAN JOURNAL OF EARTH SCIENCES
(2020)
Article
Geosciences, Multidisciplinary
Rose N. Cobbett, Maurice Colpron, James L. Crowley, Fabrice Cordey, Robert B. Blodgett, Micheal J. Orchard
Summary: The Earn Group in central Yukon records the transition from a passive to an active margin in western Laurentia during the Late Devonian, demonstrating the onset of deformation and crustal evolution. This magmatic activity coincides with the initiation of arc magmatism in the allochthonous Yukon-Tanana terrane, indicating extension related to rifting and opening of the Slide Mountain ocean in a back-arc setting. The magmatic rocks in central Yukon represent part of a remnant continental arc and back-arc that was stranded behind the Slide Mountain ocean in the Mississippian.
CANADIAN JOURNAL OF EARTH SCIENCES
(2021)
Article
Geochemistry & Geophysics
Carol D. Frost, Fabio A. Da Prat
Summary: This study identifies three different varieties of Neoarchean SPG in the Archean Wyoming Province, USA, each formed through different processes and under different tectonic settings. The calcic suites originate from dehydration melting or water excess melting of hornblende-plagioclase rocks at relatively high temperature, while suites composed entirely of SPG formed by partial melting of metasedimentary rocks at lower temperatures. Suites with both weakly and strongly peraluminous granite may form by different processes involving biotite or assimilation of aluminous melts of felsic crust. The appearance of SPG in the Neoarchean rock record indicates the formation of strong, thick continental crust through subduction, leading to the development of mature sedimentary cover and eventual collisional orogeny.
AMERICAN MINERALOGIST
(2021)
Review
Geochemistry & Geophysics
H. Bedle, C. M. Cooper, C. D. Frost
Summary: The factors promoting stability of Archean cratons were investigated, emphasizing the importance of buoyancy, viscosity, and integrated yield strength for the intrinsic strength of a craton, as well as the early cratonization in forming stable Archean cratonic lithosphere. Subsequent processes such as subduction, rifting, and mantle plumes can modify and weaken cratonic lithosphere by introducing heat, fluids, and partial melts. The survivability of Archean cratons depends on avoiding certain tectonic processes and the extent of modification, as their stability decreases as the Earth cools.
Editorial Material
Geosciences, Multidisciplinary
Gabriel Filippelli, Lisa Beal, Harihar Rajaram, Amir AghaKouchak, Michael A. Balikhin, Georgia Destouni, Amy East, Claudio Faccenna, Fabio Florindo, Carol Frost, Stephen Griffies, Matthew Huber, Noe Lugaz, Isabelle Manighetti, Laurent Montesi, Benoit Pirenne, Peter Raymond, Sana Salous, Taylor Schildgen, Susan Trumbore, Michael Wysession, Marguerite Xenopoulos, Minghua Zhang
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Luke Ootes, Dejan Milidragovic, Richard Friedman, Corey Wall, Fabrice Cordey, Yan Luo, Gabrielle Jones, D. Graham Pearson, Anika Bergen
Summary: This study analyzes the data of rocks and detrital zircons to reveal the tectonic environment and evolution of eastern Stikinia. The results suggest that eastern Stikinia formed on Paleozoic ocean floor during the Carboniferous to early Permian, and it is related to Wrangellia. This is consistent with previous research findings.
Article
Geosciences, Multidisciplinary
Paul A. Bedrosian, Carol D. Frost
Summary: A new 3-D resistivity model obtained from the inversion of magnetotelluric data reveals the crustal and upper-mantle structure of the Wyoming Province and its adjacent areas. The model shows high-conductivity belts along the northern, eastern, and southern margins of the province, which are interpreted as sutures marking remnants of Paleoproterozoic orogens. The model also suggests a shift in the northern boundary of the province and identifies a composite orogen separating the Wyoming Province and Medicine Hat block. The results indicate that the lithospheric modification in the Wyoming Province is resistant to heat and fluid influx associated with extension and plumes, suggesting a thicker lithospheric root remains in place.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2023)
Article
Geology
Robert G. H. Raynolds, Gary D. Johnson, Carol D. Frost, H. Michael Keller, Michael G. McMurtry, Charles F. Visser
Summary: The use of magnetic polarity stratigraphy allows precise dating of Upper Miocene and Plio-Pleistocene Siwalik sediments in the eastern Potwar Plateau by correlating them with the global magnetic polarity time scale. Through paleomagnetic calibration, measured sections can be extrapolated across broad areas to create new time maps based on the observation of stratigraphic strike line patterns on Google Earth imagery. These maps provide accurate dating of fossils and robust interpretations of the influence of growing folds and faults on the evolving fluvial geomorphology and depositional patterns of the region.
JOURNAL OF HIMALAYAN EARTH SCIENCES
(2022)
Article
Geology
Fabrice Cordey
Summary: The ophiolitic melange on Rhodes Island in the Eastern Mediterranean region is a significant proxy for studying the geodynamic evolution of the Paleotethyan and Neotethyan basins, potentially originating from two distinct periods in the Northern Neotethyan basin.
Article
Geosciences, Multidisciplinary
Todd A. LaMaskin, Jonathan A. Rivas, David L. Barbeau, Joshua J. Schwartz, John A. Russell, Alan D. Chapman
Summary: Differing interpretations of geophysical and geologic data have led to debate regarding the continent-scale plate configuration, subduction polarity, and timing of collisional events on the western North American plate margin in pre-mid-Cretaceous time. New detrital zircon U-Pb ages from clastic rocks in the Klamath Mountains of northern California and southern Oregon provide evidence supporting the long-lived, east-dipping subduction and endemic origin models over the collision and exotic origin models. These findings highlight the importance of understanding the tectonic history of the western North American plate margin.
GEOLOGICAL SOCIETY OF AMERICA BULLETIN
(2022)
Article
Geosciences, Multidisciplinary
Luke Ootes, Dejan Milidragovic, Richard Friedman, Corey Wall, Fabrice Cordey, Yan Luo, Gabrielle Jones, D. Graham Pearson, Anika Bergen
Summary: This study presents igneous and detrital zircon data from the Cordillera of Canada and Alaska, specifically focusing on the controversial origins of certain terranes like Stikinia. The research evaluates the role of juvenile and ancient crust in the evolution of Stikinia and the tectonic environment of magmatism, providing insight into the geological history of the region. The data suggest that eastern Stikinia formed on Paleozoic ocean floor during the Carboniferous to early Permian, highlighting the complex tectonic history of the area.