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Three-dimensional strain accumulation and partitioning in an arcuate orogenic wedge: An example from the Himalaya GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Suoya Fan; Michael A. Murphy
In this study, we use published geologic maps and cross-sections to construct a three-dimensional geologic model of major shear zones that make up the Himalayan orogenic wedge. The model incorporates microseismicity, megathrust coupling, and various derivatives of the topography to address several questions regarding observed crustal strain patterns and how they are expressed in the landscape. These
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Jurassic tectonics of the eastern North China Craton: Response to initial subduction of the Paleo-Pacific Plate GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Wenxing Hao; Rixiang Zhu; Guang Zhu
The Yanshan fold-and-thrust belt (YFTB) on the northern margin of the eastern North China Craton (NCC) contains a succession of Jurassic volcano-sedimentary rocks that record the response of the NCC to the initial stages of subduction of the Paleo-Pacific Plate. We present stratigraphic profiles and new zircon U-Pb data from four basins in the YFTB to constrain the ages of the Jurassic lithological
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Evidence for mixed contribution of mantle and lower and upper crust to the genesis of Jurassic I-type granites from Macao, SE China GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Pedro Quelhas; João Mata; Ágata Alveirinho Dias
Much controversy has occurred in the past few decades regarding the nature of the sources, the petrogenetic processes, and the tectonic regime(s) of the Jurassic magmatism within the Southeast China magmatic belt. This study aims to contribute to the discussion with mineral chemistry, and whole-rock element and Sr-Nd-Hf-Pb isotopic geochemical data from granitic rocks and microgranular mafic enclaves
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Trace-elemental and petrographic constraints on the severity of hydrographic restriction in the silled Midland Basin during the late Paleozoic ice age GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Junwen Peng; Qilong Fu; Toti E. Larson; Xavier Janson
Enrichment of redox-sensitive trace elements in ancient marine shales is conventionally believed to be controlled by marine benthic redox conditions, whereas the influence of hydrographic conditions on trace element enrichment pattern has been rarely considered. Here, we present newly obtained data sets from the Upper Pennsylvanian organic-rich Cline Shale in the Midland Basin, Texas, to illustrate
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Thrusting, exhumation, and basin fill on the western margin of the South China block during the India-Asia collision GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Kai Cao; Philippe Hervé Leloup; Guocan Wang; Wei Liu; Gweltaz Mahéo; Tianyi Shen; Yadong Xu; Philippe Sorrel; Kexin Zhang
The pattern and timing of deformation in southeast Tibet resulting from the early stages of the India-Asia collision are crucial factors to understand the growth of the Tibetan Plateau, but they remain poorly constrained. Detailed field mapping, structural analysis, and geochronological and thermochronological data along a 120 km section of the Ludian-Zhonghejiang fold-and-thrust belt bounding the
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Infaunal response during the end-Permian mass extinction GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Mao Luo; Luis A. Buatois; G.R. Shi; Zhong-Qiang Chen
The end-Permian mass extinction (EPME) profoundly shaped shallow marine ecosystems. Although much has been learned about this event based on the body-fossil record, the global infaunal response to the EPME, as represented by ichnofossils, is much less understood. Here we analyze secular changes in ichnodiversity and ichnodisparity from the late Permian to the Middle Triassic based on a global trace-fossil
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On the reconciliation of biostratigraphy and strontium isotope stratigraphy of three southern Californian Plio-Pleistocene formations GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Alexandra J. Buczek; Austin J.W. Hendy; Melanie J. Hopkins; Jocelyn A. Sessa
The San Diego Formation, Pico Formation, Careaga Sandstone, and Foxen Mudstone of southern California are thought to be late Pliocene to early Pleistocene; however, numerical ages have not been determined. Following assessment of diagenetic alteration via multiple methods including scanning electron microscopy (SEM), X-ray diffraction (XRD), and minor elemental concentrations, we attempted to use strontium
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The Olympic-Wallowa lineament: A new look at an old controversy GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Stephen P. Reidel; Karl R. Fecht; Ingrid L. Hutter (Harrold); Terry L. Tolan; Mickie A. Chamness
The Olympic-Wallowa lineament (OWL) is an alignment of geologic structures extending nearly 650 km across the Pacific Northwest (PNW) and has been a controversial feature since it was first described nearly 80 years ago. It extends from the Olympic Peninsula–Puget Sound area of western Washington to the Wallowa Mountains of northeast Oregon, crossing through the Columbia Basin and forming the southern
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Transition from the lithospheric to asthenospheric mantle-derived magmatism in the Early Jurassic along eastern Bangong–Nujiang Suture, Tibet: Evidence for continental arc extension induced by slab rollback GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Wang-Chun Xu; Hong-Fei Zhang; Li-Ran Chen; Bi-Ji Luo; Liang Guo; Jing-Liang Guo
The transition of the geochemical signature in mafic rocks along the eastern Bangong–Nujiang suture in Tibet contains important information about geodynamic processes in the upper mantle. This study recognized two episodes of Early Jurassic gabbros from the Kaqiong terrane, a microblock within the Bangong–Nujiang suture zone. Early gabbros (ca. 197–191 Ma) appear as lenses in the basement complex and
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Multiproxy records in middle–late Miocene sediments from the Wushan Basin: Implications for climate change and tectonic deformation in the northeastern Tibetan Plateau GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Weitao Wang; Peizhen Zhang; Zhicai Wang; Kang Liu; Hongyan Xu; Caicai Liu; Huiping Zhang; Wenjun Zheng; Dewen Zheng
To help understand the relationship between global cooling and Tibetan uplift in the middle to late Miocene, multiple proxy data including carbonate stable isotope records, magnetic susceptibility, and sediment color references were obtained from a magnetostratigraphic section (14.5–6.0 Ma) of the Wushan Basin along the northeastern margin of the Tibetan Plateau. New proxies identify two phase changes
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Inhomogeneous thinning of a cratonic lithospheric keel by tectonic extension: The Early Cretaceous Jiaodong Peninsula–Liaodong Peninsula extensional provinces, eastern North China craton GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Junlai Liu; Mo Ji; Jinlong Ni; Liang Shen; Yuanyuan Zheng; Xiaoyu Chen; John P. Craddock
The mechanisms of lithospheric thinning and craton destruction have been hotly debated in the last decades. The Early Cretaceous Jiaodong and Liaodong extensional provinces (JEP and LEP, respectively) of the eastern North China craton are typical areas where the cratonic Archean lithosphere has been intensely extended and thinned. Various extensional structures, e.g., metamorphic core complexes (MCCs)
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Crustal and upper mantle structure beneath the South China Sea and Indonesia GSA Bull. (IF 3.558) Pub Date : 2021-01-01 V. Corchete
A three-dimensional (3-D) S-velocity model for the crust and upper mantle beneath the South China Sea and Indonesia is presented, determined by means of Rayleigh wave analysis, in the depth range from 0 km to 400 km. The crustal and lithospheric mantle structure of this study area was previously investigated using several methods and databases. Due to their low resolution, a 3-D structure for this
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Provenance changes across the mid-Cretaceous unconformity in basins of northeastern China: Evidence for an integrated paleolake system and tectonic transformation GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Shuang-Qing Li; Song He; Fukun Chen
Detrital zircon U-Pb dating and whole-rock Nd isotopic analyses were carried out on selected stratigraphic horizons across a major unconformity between synrift and postrift stages in the Songliao Basin and Dasanjiang basin group of NE China to constrain the crustal evolution of the source area providing detritus into these basins. The strata underlying the mid-Cretaceous unconformity in the Songliao
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Late Cenozoic drainage reorganization of the paleo-Yangtze river constrained by multi-proxy provenance analysis of the Paleo-lake Xigeda GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Bin Deng; David Chew; Chris Mark; Shugen Liu; Nathan Cogné; Lei Jiang; Gary O’Sullivan; Zhiwu Li; Jinxi Li
The Late Cenozoic evolution of the major river networks draining eastern Tibet has major tectonic implications for the development of the plateau but remains highly contentious. In this study from the southeastern margin of the Tibetan Plateau, we constrain the evolution of the Paleo-lake Xigeda (recorded by the lacustrine Plio-Pleistocene Xigeda Formation) using combined fission-track (FT) dating
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Rifting and subduction records of the Paleo–Tethys in North Laos: Constraints from Late Paleozoic mafic and plagiogranitic magmatism along the Song Ma tectonic zone GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Yuzhi Zhang; Xue Yang; Yuejun Wang; Xin Qian; Yukun Wang; Qiyu Gou; Vongpaseuth Senebouttalath; Aimei Zhang
In Southeast Asia, the Jinshajiang–Ailaoshan suture in Southwest China and the Song Ma zone in Vietnam were generally accepted as the amalgamation boundary of the South China and Simao/Indochina blocks. However, the tectonic location of the Paleotethyan suture in North Laos and its tectonic affinity remain ambiguous. To address this issue, we present the geochemical and geochronological data of a set
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Distinguishing tectonic versus climatic forcing on landscape evolution: An example from SE Tibetan Plateau GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Fangbin Liu; Martin Danišík; Dewen Zheng; Kerry Gallagher; Junsheng Nie
Distinguishing climate from tectonic forcing in shaping the Earth’s surface has been a long-standing issue in the Earth sciences. Great debate exists regarding when and how the SE Tibetan Plateau achieved its current low-relief topography, and both lateral extrusion and lower crust flow have been proposed as the dominant mechanism. Reconstruction of the exhumation history of the SE Tibetan Plateau
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Has Earth ever been ice-free? Implications for glacio-eustasy in the Cretaceous greenhouse age using high-resolution sequence stratigraphy GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Wen Lin; Janok P. Bhattacharya; Brian R. Jicha; Brad S. Singer; William Matthews
Controls on high-frequency sequences formed during super-greenhouse conditions in the Late Cretaceous Western Interior Seaway remain equivocal because of the active foreland basin tectonic setting and the lack of direct evidence of polar glaciations to support a glacio-eustatic origin. This paper quantifies eustatic sea-level changes based on high-resolution sequence stratigraphic analysis and improved
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Provenance and tectonic setting of late Paleozoic sedimentary rocks from the Alxa Tectonic Belt (NW China): Implications for accretionary tectonics of the southern Central Asian Orogenic Belt GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Dongfang Song; Wenjiao Xiao; Brian F. Windley; Chunming Han
The Central Asian Orogenic Belt has long been considered the largest Phanerozoic accretionary orogen in the world; it developed through the subduction and final closure of the Paleo–Asian Ocean. However, the architecture and duration of the accretionary orogenesis of the Central Asian Orogenic Belt are still controversial despite decades of investigation. In this study, we present field, compositional
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Cyclostratigraphic calibration of the Eifelian Stage (Middle Devonian, Appalachian Basin, Western New York, USA) GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Damien Pas; Anne-Christine Da Silva; D. Jeffrey Over; Carlton E. Brett; Lauren Brandt; Jin-Si Over; Frederik J. Hilgen; Mark J. Dekkers
Over the past decade the integration of astrochronology and U/Pb thermal ionization mass spectrometry dating has resulted in major improvements in the Devonian time scale, which allowed for accurate determination of ages and rates of change in this critical interval of Earth history. However, widely different durations have been published for the Middle Devonian Eifelian stage. Here we aim to solve
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Deep-water channel morphologies, architectures, and population densities in relation to stacking trajectories and climate states GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Chenglin Gong; Ronald J. Steel; Kun Qi; Yingmin Wang
Deep-water channel morphologies, stratigraphy, and population densities in relation to stacking trajectories and climate states remain poorly constrained, and are highlighted by a sampling of 142 submarine channels. From the perspective of channel kinematics, turbidite channels exhibit tripartite lateral - random - vertical trajectories or unidirectional channel-complex trajectories, whereas contourite
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Quaternary slip rates on the White Mountains fault zone, eastern California: Implications for comparing geologic to geodetic slip rates across the Walker Lane GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Zachery M. Lifton; Jeffrey Lee; Kurt L. Frankel; Andrew V. Newman; Jeffrey M. Schroeder
The White Mountains fault zone in eastern California is a major fault system that accommodates right-lateral shear across the southern Walker Lane. We combined field geomorphic mapping and interpretation of high-resolution airborne light detection and ranging (LiDAR) digital elevation models with 10Be cosmogenic nuclide exposure ages to calculate new late Pleistocene and Holocene right-lateral slip
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Ordo-Silurian assemblage in the Indochina interior: Geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic constraints of early Paleozoic granitoids in South Laos GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Yuejun Wang; Yuzhi Zhang; Xin Qian; Vongpaseuth Senebouttalath; Yang Wang; Yukun Wang; Chengshi Gan; Khin Zaw
In order to verify the early Paleozoic accretionary assemblage in the Indochina interior and constrain the Prototethyan tectonic evolution in Southeast Asia, this study presents a set of new U-Pb geochronological, elemental, and Sr-Nd-Pb-Hf-O isotopic data for the fifty-two representative granitoids in South Laos. The granitoids from the Kontum terrane, Tam Ky-Phuoc Son tectonic zone, and southern
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Investigating the formation of the Cretaceous Western Interior Seaway using landscape evolution simulations GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Ching Chang; Lijun Liu
Transient intraplate sedimentation like the widespread Late Cretaceous Western Interior Seaway, traditionally considered a flexural foreland basin of the Sevier orogeny, is now generally accepted to be a result of dynamic topography due to the viscous force from mantle downwelling. However, the relative contributions of flexural versus dynamic subsidence are poorly understood. Furthermore, both the
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Changes in productivity associated with algal-microbial shifts during the Early Triassic recovery of marine ecosystems GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Yong Du; Huyue Song; Jinnan Tong; Thomas J. Algeo; Zhe Li; Haijun Song; Jiandong Huang
The recovery of marine ecosystems in the aftermath of the Permian-Triassic mass extinction was accompanied by significant carbon-cycle perturbations, as reflected in large-amplitude global excursions in Lower Triassic carbonate carbon isotope records. In the present study, we generated paired carbonate carbon (δ13Ccarb), organic carbon (δ13Corg), and nitrogen (δ15N) isotope records along with molar
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Loess in eastern equatorial Pangea archives a dusty atmosphere and possible upland glaciation GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Lily S. Pfeifer; Gerilyn S. Soreghan; Stéphane Pochat; Jean Van Den Driessche
Carboniferous–Permian strata in basins within the Central Pangean Mountains in France archive regional paleoequatorial climate during a unique interval in geological history (Pangea assembly, ice-age collapse, megamonsoon inception). The voluminous (∼1.5 km) succession of exclusively fine-grained red beds that comprises the Permian Salagou Formation (Lodève Basin, France) has long been interpreted
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Triassic–Jurassic evolution of the eastern North China Craton: Insights from the Lushun-Dalian area, South Liaodong Peninsula, NE China GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Zhiheng Ren; Wei Lin; Michel Faure; Lingtong Meng; Huabiao Qiu; Jipei Zeng
The Lushun-Dalian area of the South Liaodong Peninsula, in NE China, located in the SE margin of the North China Craton (NCC) exposes a suite of Middle-Late Proterozoic low-grade metamorphic sedimentary rocks which can be divided into a lower competent layer, a middle incompetent layer, and an upper competent layer on the basis of lithology and deformation style. Two stages of deformation recorded
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Biomarker evidence of algal-microbial community changes linked to redox and salinity variation, Upper Devonian Chattanooga Shale (Tennessee, USA) GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Yi Song; Geoffrey J. Gilleaudeau; Thomas J. Algeo; D. Jeffrey Over; Timothy W. Lyons; Ariel D. Anbar; Shucheng Xie
Late Devonian marine systems were characterized by major environmental perturbations and associated biotic community changes linked to climate change and widespread oceanic anoxia. Here, we provide high-resolution lipid biomarker chemostratigraphic records from the Upper Devonian Chattanooga Shale (Tennessee, USA) to investigate algal-microbial community changes in the southern Illinois Basin that
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Geochemistry of contrasting stream types, Taylor Valley, Antarctica GSA Bull. (IF 3.558) Pub Date : 2021-01-01 Russell S. Harmon; Deborah L. Leslie; W. Berry Lyons; Kathleen A. Welch; Diane M. McKnight
The McMurdo Dry Valley region is the largest ice-free area of Antarctica. Ephemeral streams flow here during the austral summer, transporting glacial meltwater to perennially ice-covered, closed basin lakes. The chemistry of 24 Taylor Valley streams was examined over the two-decade period of monitoring from 1993 to 2014, and the geochemical behavior of two streams of contrasting physical and biological
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Exploring records of typhoon variability in eastern China over the past 2000 years GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Yang Yang; Liang Zhou; Alexandre Normandeau; Jianjun Jia; Qijun Yin; Ya Ping Wang; Benwei Shi; Lei Gao; Shu Gao
How climate controls tropical cyclone variability has critical implications for modern human society but is not well understood due to the short length of observational records. To probe this knowledge gap, we present a synthesis of intense typhoon activity from the northwestern Pacific over the past 2000 years, which is supported by a new, well-resolved tidal flat sedimentary record from the Jiangsu
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Metamorphic evolution of high-pressure felsic and pelitic granulites from the Qianlishan Complex and tectonic implications for the Khondalite Belt, North China Craton GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Shangjing Wu; Changqing Yin; Donald W. Davis; Jian Zhang; Jiahui Qian; Hengzhong Qiao; Yanfei Xia; Jingna Liu
High-pressure felsic granulites in association with pelitic granulites are widely distributed in the Qianlishan Complex of the Khondalite Belt, North China Craton. A link between “inter-layered” felsic and pelitic granulites was established based on comprehensive metamorphic analysis, revealing that they record similar metamorphic stages: peak pressure (M1), post-peak decompression (M2), and late retrograde
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Neoproterozoic Blaini Formation of Lesser Himalaya, India: Fiction and Fact GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Sumit Dey; Prabir Dasgupta; Kaushik Das; Abdul Matin
The long-conceived idea of the glacial origin of Blaini diamictite of Lesser Himalayan Neoproterozoic succession reached its maxima when the diamictites and capping pink limestone were attributed to the Neoproterozoic Snowball Earth event and its aftermath, respectively. Occurrences of diamictite-limestone association in two different levels have also been correlated with the Sturtian and Marinoan
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Constraints from cosmogenic nuclides on the glaciation and erosion history of Dove Bugt, northeast Greenland GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Daniel Søndergaard Skov; J.L. Andersen; J. Olsen; B.H. Jacobsen; M.F. Knudsen; J.D. Jansen; N.K. Larsen; D.L. Egholm
The intricate interplay between subglacial topography and ice-sheet dynamics is key to the evolution of large ice sheets, but in Greenland as elsewhere the effects of long-term glacial history on landscape evolution remain poorly constrained. Here we measure abundances of cosmogenic 10Be and 26Al in bedrock and transported boulders to unveil the glaciation and erosion history of Dove Bugt, northeast
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Early Devonian (415–400 Ma) A-type granitoids and diabases in the Wuyishan, eastern Cathaysia: A signal of crustal extension coeval with the separation of South China from Gondwana GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Yujia Xin; Jianhua Li; Lothar Ratschbacher; Guochun Zhao; Yueqiao Zhang; Shuwen Dong; Xiao-Ping Xia; Yingqi Yu
The evolution of the South China continental crust and its linkage to the assembly and rifting of eastern Gondwana are key issues in the understanding of the early Paleozoic evolution of eastern Asia. We report U-Pb zircon ages and geochemical and Lu-Hf isotopic data for the South Fufang and Yingshang granitoids and the Mayuan diabases from the Wuyishan of eastern South China. The zircons yielded U-Pb
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The role of eolian-fluvial interactions and dune dams in landscape change, late Pleistocene–Holocene, Mojave Desert, USA GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Mark R. Sweeney; Eric V. McDonald; Lucas P. Chabela; Paul R. Hanson
The formation of the Kelso Dunes in the eastern Mojave Desert, California, was a landscape-changing event triggered by an increase in sediment supply that followed the incision of Afton Canyon by the Mojave River ca. 25 ka. Eastward migration of sand dunes occurred along a well-defined eolian transport corridor. Dunes temporarily blocked washes resulting in substantial aggradation of eolian and fluvial
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Secular evolution of the lithospheric mantle beneath the northern margin of the North China Craton: Insights from zoned olivine xenocrysts in Early Cretaceous basalts GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Yao Xu; Hongfu Zhang
Abundant zoned olivine xenocrysts from Early Cretaceous basalts of the Yixian Formation in western Liaoning Province, China, contain critical information about the nature and evolution of the lithospheric mantle of the northern North China Craton. These olivine xenocrysts are large (600–1600 µm), usually rounded and embayed, with well-developed cracks. Their cores have high and uniform forsterite (Fo)
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A clearer view of crustal evolution: U-Pb, Sm-Nd, and Lu-Hf isotope systematics in five detrital minerals unravel the tectonothermal history of northern China GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Guangyan Zhou; Christopher M. Fisher; Yan Luo; D. Graham Pearson; Long Li; Yu He; Yuanbao Wu
Much of the global picture of crustal evolution has been constructed using zircon. While this has revealed a rich and complex history, this view is necessarily incomplete because of the lithology-specific affinity of zircon and the high temperatures needed to reset the U-Pb and Lu-Hf systems inherent within it. Here we use a five mineral, multi-isotope system approach to compare the record of crustal
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Post-rift magmatism on the northern South China Sea margin GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Qiliang Sun; Tiago M. Alves; Minghui Zhao; Jean-Claude Sibuet; Gérôme Calvès; Xinong Xie
Intense magmatism in the form of widespread volcanoes and lava flows is identified in high-resolution 3-D seismic data over a post-rift sequence of the northern South China Sea (SCS). Such a magmatism post-dates the end of seafloor spreading in the SCS by at least 6.8 m.y. A detachment (boundary) fault propagating into a deep-seated magma chamber provided the main vertical pathway for magma migration
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Tectonic evolution of strike-slip zones on continental margins and their impact on the development of submarine landslides (Storegga Slide, northeast Atlantic) GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Jing Song; T.M. Alves; K.O. Omosanya; T.C. Hales; Tao Ze
Submarine landslides have affected the mid-Norwegian margin since the Last Glacial Maximum. However, the role of tectonic movements, and most especially fault reactivation, in generating landslides offshore Norway is largely unconstrained. This study uses high-quality three-dimensional seismic and borehole data to understand how landslide development is controlled by faults propagating within the uplifted
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Early Neoproterozoic magmatism in the Central Qilian block, NW China: Geochronological and petrogenetic constraints for Rodinia assembly GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Yilong Li; Wenjiao Xiao; Zhuoyang Li; Ke Wang; Jianping Zheng; Fraukje M. Brouwer
The supercontinent Rodinia existed as a coherent large landmass from 900 to 750 Ma and is now dispersed over all current major continents. Controversy has long surrounded the reconstructions of the East Asian blocks in Rodinia, especially the South China craton and nearby microcontinents. The Central Qilian block is a Precambrian microcontinent in the early Paleozoic Qilian orogenic belt, which is
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The control of preexisting faults on the distribution, morphology, and volume of monogenetic volcanism in the Michoacán-Guanajuato Volcanic Field GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Martha Gabriela Gómez-Vasconcelos; José Luis Macías; Denis Ramón Avellán; Giovanni Sosa-Ceballos; Víctor Hugo Garduño-Monroy; Guillermo Cisneros-Máximo; Paul W. Layer; Jeff Benowitz; Héctor López-Loera; Fabiola Mendiola López; Mathieu Perton
Interactions between volcanic and tectonic processes affect the distribution, morphology, and volume of eruptive products in space and time. The Queréndaro area in the eastern Michoacán-Guanajuato Volcanic Field affords an exceptional opportunity to understand these relationships. Here, a Pleistocene lava plateau and 20 monogenetic volcanoes are vented from an active ENE-striking segment of the Morelia-Acambay
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Sedimentological characteristics and aeolian architecture of a plausible intermountain erg system in Southeast China during the Late Cretaceous GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Shuo Cao; Laiming Zhang; Chengshan Wang; Jing Ma; Jie Tan; Zhihui Zhang
Along with intensification of global warming, severe desertification has already impaired human sustainable development. In a near-future greenhouse world, the total area of desert will increase, and new types of desert may emerge. During the “greenhouse” Cretaceous, conventional large paleo-ergs developed in broad topographic basins, and many possible ergs developed in small-scale intermountain basins
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Transition from Late Jurassic rifting to middle Cretaceous dynamic foreland, southwestern U.S. and northwestern Mexico GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Timothy F. Lawton; Jeffrey M. Amato; Sarah E.K. Machin; John C. Gilbert; Spencer G. Lucas
Subsidence history and sandstone provenance of the Bisbee basin of southwestern New Mexico, southern Arizona, and northern Sonora, Mexico, demonstrate basin evolution from an array of Late Jurassic–Early Cretaceous rift basins to a partitioned middle Cretaceous retroarc foreland basin. The foreland basin contained persistent depocenters that were inherited from the rift basin array and determined patterns
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A Late Miocene magmatic flare-up in West Sulawesi triggered by Banda slab rollback GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Xiaoran Zhang; Chia-Yu Tien; Sun-Lin Chung; Adi Maulana; Musri Mawaleda; Mei-Fei Chu; Hao-Yang Lee
Cenozoic magmatism occurs throughout West Sulawesi, Indonesia, yet its detailed evolution remains enigmatic due mainly to the scarcity of precise dating. Here, we report new whole-rock geochemical and zircon U-Pb-Hf isotopic data of plutonic/volcanic rocks and river sediments from West Sulawesi to constrain the petrogenesis and magmatic tempo. The magmatic rocks are intermediate to felsic (SiO2 = 58
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Tectonic evolution of the Chinese Tianshan Orogen from subduction to arc-continent collision: Insight from polyphase deformation along the Gangou section, Central Asia GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Pengfei Li; Min Sun; Gideon Rosenbaum; Keda Cai; Chao Yuan; Fred Jourdan; Xiaoping Xia; Yingde Jiang; Yunying Zhang
The Central Asian Orogenic Belt, as the largest accretionary orogen on Earth, is an ideal candidate to study the geodynamics of convergent plate boundaries through a prolonged period. The evolution of this orogen has been explained by different tectonic models, which incorporated one, or a combination, of the following mechanisms: lateral stacking of arc systems along major shear zones, arc amalgamation
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Late Quaternary landscape evolution and bioclimatic change in the central Great Plains, USA GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Anthony L. Layzell; Rolfe D. Mandel
A systematic study of floodplains, terraces, and alluvial fans in the Republican River valley of south-central Nebraska provided a well-dated, detailed reconstruction of late Quaternary landscape evolution and resolved outstanding issues related to previously proposed Holocene terrace sequences. Stable carbon isotope (δ13C) values determined on soil organic matter from buried soils in alluvial landforms
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Synrift basin inversion: Significant role of synchronous strike-slip motion in a rift basin GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Lei Huang; Chi-yang Liu; Jun-feng Zhao; Dong-dong Zhang
In rift basins with superposed strike-slip deformation, the structural style of wrench elements and the roles they play in synrift architecture and evolution are important, poorly understood issues for basin analysis and hydrocarbon exploration. The NE-SW–striking Tan-Lu fault zone, located in eastern China, runs through the Liaodong Bay subbasin within the Cenozoic Bohai Bay Basin and experienced
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Carbonate platform production during the Cretaceous GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Alexandre Pohl; Yannick Donnadieu; Yves Godderis; Cyprien Lanteaume; Alex Hairabian; Camille Frau; Julien Michel; Marie Laugie; John J.G. Reijmer; Christopher R. Scotese; Jean Borgomano
Platform carbonates are among the most voluminous of Cretaceous deposits. The production of carbonate platforms fluctuated through time. Yet, the reasons for these fluctuations are not well understood, and the underlying mechanisms remain largely unconstrained. Here we document the long-term trend in Cretaceous carbonate platform preservation based on a new data compilation and use a climate-carbon
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Petrological, geochronological, and geochemical potential accounting for continental subduction and exhumation: A case study of felsic granulites from South Altyn Tagh, northwestern China GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Yunshuai Li; Jianxin Zhang; Shengyao Yu; Yanguang Li; Hu Guo; Jian Zhang; Changlei Fu; Hui Cao; Mengqi Jin; Zhihui Cai
Deciphering the formation and geodynamic evolution of high-pressure (HP) granulites in a collisional orogeny can provide crucial constraints on the geodynamic evolution of subduction-exhumation. To fully exploit the geodynamic potential of metamorphic rocks, it is necessary to constrain the metamorphic ages, although it is difficult to link zircon and monazite ages to metamorphic evolution. A good
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Early Mesozoic synrift Eagle Mills Formation and coeval siliciclastic sources, sinks, and sediment routing, northern Gulf of Mexico basin GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Bruce C. Frederick; Mike D. Blum; John W. Snedden; Richard H. Fillon
The sedimentary architecture and provenance of the early Mesozoic incipient northern Gulf of Mexico basin remains controversial due to both lack of outcrop exposure and sample scarcity across the southern United States with subcrop depths approaching 6 km. The Eagle Mills Formation and coeval deposition across the northern Gulf of Mexico provides both a stratigraphic foundation for some ∼15-km-thick
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Hazards from lava–river interactions during the 1783–1784 Laki fissure eruption GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Frances Boreham; Katharine Cashman; Alison Rust
Interactions between lava flows and surface water are not always considered in hazard assessments, despite abundant historical and geological evidence that they can create significant secondary hazards (e.g., floods and steam explosions). We combine contemporary accounts of the 1783–1784 Laki fissure eruption in southern Iceland with morphological analysis of the geological deposits to reconstruct
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Clumped isotope constraints on changes in latest Pleistocene hydroclimate in the northwestern Great Basin: Lake Surprise, California GSA Bull. (IF 3.558) Pub Date : 2020-11-01 L.M. Santi; A.J. Arnold; D.E. Ibarra; C.A. Whicker; J.A. Mering; R.B. Lomarda; J.M. Lora; A. Tripati
During the Last Glacial Maximum (LGM) and subsequent deglaciation, the Great Basin in the southwestern United States was covered by numerous extensive closed-basin lakes, in stark contrast with the predominately arid climate observed today. This transition from lakes in the Late Pleistocene to modern aridity implies large changes in the regional water balance. Whether these changes were driven by increased
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Channel narrowing by inset floodplain formation of the lower Green River in the Canyonlands region, Utah GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Alexander E. Walker; Johnnie N. Moore; Paul E. Grams; David J. Dean; John C. Schmidt
The lower Green River episodically narrowed between the mid-1930s and present day through deposition of new floodplains within a wider channel that had been established and/or maintained during the early twentieth century pluvial period. Comparison of air photos spanning a 74-yr period (1940–2014) and covering a 61 km study area shows that the channel narrowed by 12% from 138 ± 3.4 m to 122 ± 2.1 m
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From extension to tectonic inversion: Mid-Cretaceous onset of Andean-type orogeny in the Lhasa block and early topographic growth of Tibet GSA Bull. (IF 3.558) Pub Date : 2020-11-01 Jian-Gang Wang; Xiumian Hu; Eduardo Garzanti; Marcelle K. BouDagher-Fadel; Zhi-Chao Liu; Juan Li; Fu-Yuan Wu
Recent studies have indicated that an Andean-type orogen (Lhasaplano) developed on the Lhasa block in the Cretaceous during northward subduction of Neo-Tethyan oceanic lithosphere. When and how uplift of the Lhasaplano began, however, has remained controversial. This article integrates stratigraphic, sedimentological, tectonic, and provenance data from the latest marine to nonmarine strata in the Linzhou
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A Laurentian margin subduction perspective: Geodynamic constraints from phase equilibria modeling of barroisite greenstones, northern USA Appalachians GSA Bull. (IF 3.558) Pub Date : 2020-11-01 I.W. Honsberger; J. Laird; J.E. Johnson
Phase equilibria modeling of sodic-calcic amphibole-epidote assemblages in greenstones in the northern Appalachians, USA, is compatible with relatively shallow subduction of the early Paleozoic Laurentian margin along the Laurentia-Gondwana suture zone during closure of a portion of the Iapetus Ocean basin. Pseudosection and isopleth calculations demonstrate that peak metamorphic conditions ranged
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Pliocene short-term climate changes preserved in continental shallow lacustrine-palustrine carbonates: Western Opache Formation, Atacama Desert, Chile GSA Bull. (IF 3.558) Pub Date : 2020-09-01 Carol B. de Wet; Andrew P. de Wet; Linda Godfrey; Elizabeth Driscoll; Samuel Patzkowsky; Chi Xu; Sophia Gigliotti; Melina Feitl
Multiple climate proxies indicate episodic changes in moisture levels within an ∼1 Ma duration (early–mid Pliocene) interval. Limestones within the Opache Formation, Calama Basin, Atacama Desert region, Chile, contain evidence for wetter and drier periods on short time scales. Proxies include carbonate lithological changes, paleontology (stromatolites, oncolites, gastropods, ostracods and diatoms)
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How a strong low-angle normal fault formed: The Whipple detachment, southeastern California GSA Bull. (IF 3.558) Pub Date : 2020-09-01 Gary J. Axen
Many low-angle normal faults (dip ≤30°) accommodate tens of kilometers of crustal extension, but their mechanics remain contentious. Most models for low-angle normal fault slip assume vertical maximum principal stress σ1, leading many authors to conclude that low-angle normal faults are poorly oriented in the stress field (≥60° from σ1) and weak (low friction). In contrast, models for low-angle normal
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Neoarchean large igneous provinces on the Kaapvaal Craton in southern Africa re-define the formation of the Ventersdorp Supergroup and its temporal equivalents GSA Bull. (IF 3.558) Pub Date : 2020-09-01 Ashley Gumsley; Joaen Stamsnijder; Emilie Larsson; Ulf Söderlund; Tomas Naeraa; Michiel de Kock; Anna Sałacińska; Aleksandra Gawęda; Fabien Humbert; Richard Ernst
U-Pb geochronology on baddeleyite is a powerful technique that can be applied effectively to chronostratigraphy. In southern Africa, the Kaapvaal Craton hosts a well-preserved Mesoarchean to Paleoproterozoic geological record, including the Neoarchean Ventersdorp Supergroup. It overlies the Witwatersrand Supergroup and its world-class gold deposits. The Ventersdorp Supergroup comprises the Klipriviersberg
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Neotectonics of the Bailongjiang and Hanan faults: New insights into late Cenozoic deformation along the eastern margin of the Tibetan Plateau GSA Bull. (IF 3.558) Pub Date : 2020-09-01 Hailong Li; Yueqiao Zhang; Shuwen Dong; Junlong Zhang; Yujun Sun; Qiangmao Wang
The way that far-field stresses and deformation propagated eastward in response to the growth and extrusion of the northeastern Tibetan Plateau remains a crucial scientific issue. This paper focuses on the Bailongjiang and Hanan faults, which are the easternmost part of the East Kunlun fault in northeast Tibet. Based on new field geological investigations, structural data, satellite imagery interpretation
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Two late Carboniferous belts of Nb-enriched mafic magmatism in the Eastern Tianshan: Heterogeneous mantle sources and geodynamic implications GSA Bull. (IF 3.558) Pub Date : 2020-09-01 Yunying Zhang; Chao Yuan; Min Sun; Xiaoping Long; Zongying Huang; Yingde Jiang; Pengfei Li; Long Du
Identification of subduction to post-collisional tectonic transitions is critical to the study of orogenic belts. To characterize such a transition in the Tianshan Orogenic Belt, a systematic study was conducted on the late Carboniferous (305–301 Ma) Hongshankou dolerite and Dikan’er basalt of Eastern Tianshan. The Hongshankou dolerites have relatively high Ti and Nb contents, akin to Nb-enriched arc
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Emplacement of unusual rhyolitic to basaltic ignimbrites during collapse of a basalt-dominated caldera: The Halarauður eruption, Krafla (Iceland) GSA Bull. (IF 3.558) Pub Date : 2020-09-01 Shane M. Rooyakkers; John Stix; Kim Berlo; Simon J. Barker
Deposits of the ca. 110 ka Halarauður eruption of Krafla caldera (reconstructed volume = 7 ± 6 km3 dense rock equivalent) include the only spatter-rich ignimbrite known in Iceland, and an exceptionally rare lava-like basaltic ignimbrite. We present a revised stratigraphy and new whole-rock major-element data set for products of this unusual event, one of only three Quaternary ignimbrite eruptions identified
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