Tectonics最新文献_第4页

Timing of Holocene Surface-Ruptures Across Adjacent Rupture-Segments Where the Jinsha River Crosses the Yushu Fault, Qinghai Province, China 中国青海省金沙江穿越玉树断裂处相邻断裂段全新世地表断裂的发生时间

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-07-04 DOI: 10.1029/2023tc007922

Mervin J. Bartholomew, Demin Liu, Andrew M. Mickelson, Lian Brugere, Tammy Rittenour, Guo Q. Sun

{"title":"Timing of Holocene Surface-Ruptures Across Adjacent Rupture-Segments Where the Jinsha River Crosses the Yushu Fault, Qinghai Province, China","authors":"Mervin J. Bartholomew, Demin Liu, Andrew M. Mickelson, Lian Brugere, Tammy Rittenour, Guo Q. Sun","doi":"10.1029/2023tc007922","DOIUrl":"https://doi.org/10.1029/2023tc007922","url":null,"abstract":"The Yushu fault, part of the Yushu–Ganzi fault zone, is one of several E-W-trending left-lateral, strike-slip fault zones that extend across the Tibetan Plateau accommodating lateral transfer of crustal material out of the collision zone between the Indian and Eurasian plates. Discontinuous left-lateral surface rupture occurred along WNW-ESE-striking, near-vertical faults during two Mw 6.9 14 April 2010 Yushu earthquakes. Geomorphic and surface-rupture characteristics change at the base of a red cliff separating the Guoqiong and Buqionggei segments. Excavations across these segments near the Jinsha River show: (a) more continuous deposition on the down-dropped side; and (b) how frequently these surface-rupture histories were linked or sequential (major to great earthquakes) versus not linked (moderate/strong to large earthquakes). Trench CUG-2011-1 and roadcut CUG-2012-1 (Guoqiong segment) were on older fan surfaces and Trench CUG-2012-2 (Buqionggei segment) crossed a narrow graben. On the Guoqiong segment, using OxCal v.4.4 that works with IntCal20 database for Bayesian-ordered ages from four 14C and nine OSL ages, surface ruptures occurred during earthquakes at 2010CE, ∼200BCE, ∼2400BCE, ∼4250BCE, ∼6750BCE, ∼7400BCE and ∼10400BCE consistent with an ∼2200-year Holocene recurrence interval. For the Buqionggei segment, Bayesian-ordered ages from six OSL ages indicate three Holocene surface ruptures occurred at 2010CE, ∼4600BCE and ∼6750BCE. Surface ruptures on both segments (suggesting linked or sequential major to great earthquakes) only occurred two to three times at 2010CE, ∼4500BCE and/or ∼6750BCE. Thus, risk of infrequent major to great Holocene earthquakes is ∼2400–∼8800 years along the Yushu fault.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"35 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141551243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Boundary Effects of Orogenic Plateaus in the Evolution of the Stress Field: The Southern Puna Study Case (26°30′–27°30′S) 造山运动台地在应力场演化过程中的边界效应：南普纳研究案例（26°30′-27°30′S）

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-06-29 DOI: 10.1029/2023tc008185

R. Quiroga, L. Giambiagi, A. Echaurren, J. Mescua, H. Pingel, G. Fuentes, M. Peña, J. Suriano, F. Martínez, C. Mpodozis, M. R. Strecker

{"title":"Boundary Effects of Orogenic Plateaus in the Evolution of the Stress Field: The Southern Puna Study Case (26°30′–27°30′S)","authors":"R. Quiroga, L. Giambiagi, A. Echaurren, J. Mescua, H. Pingel, G. Fuentes, M. Peña, J. Suriano, F. Martínez, C. Mpodozis, M. R. Strecker","doi":"10.1029/2023tc008185","DOIUrl":"https://doi.org/10.1029/2023tc008185","url":null,"abstract":"We present a study in the southern Puna (26°30′–27°30′S), aiming to explore the late Cenozoic evolution of the deformation and the stress field during its uplift. Through U-Pb geochronology, structural observations, paleostress analysis, and balanced cross-sections, we propose an structural evolutionary model over the past 24 million years, separated in four stages: Stage 1, in the late Oligocene to middle Miocene, the region experienced E-W compression. Stage 2, from middle to late Miocene, a transition from predominant compression to an incipient strike-slip regime is observed. Stage 3, from late Miocene to early Pliocene, showed a further shift in the stress field, resulting in a combination of a predominant strike-slip regime, and less predominant compressional regime. Finally, Stage 4, from late Pliocene to Quaternary, featured a dominance of strike-slip regimes. Our results show that the stress field in each stage is associated with the orogen's internal architecture and its evolution. Vertical stress variations are linked to plateau uplift, creating topographic gradients across the orogen. Horizontal rotations of the principal stress axes are caused mainly by an edge effect resulting from the growth of the plateau while it reaches a critical crustal thickness and elevation. This leads to a transfer of compression from high-lying areas to lower regions. The southernmost Puna region shows no significant evidence of normal faulting, suggesting it is not undergoing orogenic collapse associated with a regional tensional stress regime.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"40 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural Evolution, Exhumation Rates, and Rheology of the European Crust During Alpine Collision: Constraints From the Rotondo Granite—Gotthard Nappe 阿尔卑斯碰撞期间欧洲地壳的结构演变、排湿率和流变学：来自罗通多花岗岩-戈特哈德岩层的制约因素

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-06-21 DOI: 10.1029/2023tc008219

A. Ceccato, W. M. Behr, A. S. Zappone, L. Tavazzani, A. Giuliani

{"title":"Structural Evolution, Exhumation Rates, and Rheology of the European Crust During Alpine Collision: Constraints From the Rotondo Granite—Gotthard Nappe","authors":"A. Ceccato, W. M. Behr, A. S. Zappone, L. Tavazzani, A. Giuliani","doi":"10.1029/2023tc008219","DOIUrl":"https://doi.org/10.1029/2023tc008219","url":null,"abstract":"The rheology of crystalline units controls the large-scale deformation geometry and dynamics of collisional orogens. Defining a time-constrained rheological evolution of such units may help unravel the details of collisional dynamics. Here, we integrate field analysis, pseudosection calculations and in situ garnet U–Pb and mica Rb–Sr geochronology to define the structural and rheological evolution of the Rotondo granite (Gotthard nappe, Central Alps). We identify a sequence of four (D1–D4) deformation stages. Pre-collisional D1 brittle faults developed before Alpine peak metamorphism, which occurred at 34–20 Ma (U–Pb garnet ages) at 590 ± 25°C and 0.9 ± 0.1 GPa. The reactivation of D1 structures controlled the rheological evolution, from D2 reverse mylonitic shearing at amphibolite facies (520 ± 40°C and 0.8 ± 0.1 GPa) at 18–20 Ma (white mica Rb–Sr ages), to strike-slip, brittle-ductile shearing at greenschist-facies D3 (395 ± 25°C and 0.4 ± 0.1 GPa) at 14–15 Ma (white mica and biotite Rb–Sr ages), and then to D4 strike-slip faulting at shallow conditions. Although highly misoriented for the Alpine collisional stress orientation, D1 brittle structures controlled the localization of D2 ductile mylonites accommodating fast (∼3 mm/yr) exhumation rates due to their weak shear strength (<10 MPa). This structural and rheological evolution is common across External Crystalline Massifs (e.g., Aar, Mont Blanc), suggesting that the European upper crust was extremely weak during Alpine collision, its strength controlled by weak ductile shear zones localized on pre-collisional deformation structures, that in turn controlled localized exhumation at the scale of the orogen.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"193 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cretaceous Crust in the Scotia Sea: Missing Pieces in a Geological Puzzle? 斯科舍海的白垩纪地壳：地质拼图中缺失的部分？

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-06-21 DOI: 10.1029/2023tc008079

J. H. Oldenhage, W. P. Schellart, A. Beniest

{"title":"Cretaceous Crust in the Scotia Sea: Missing Pieces in a Geological Puzzle?","authors":"J. H. Oldenhage, W. P. Schellart, A. Beniest","doi":"10.1029/2023tc008079","DOIUrl":"https://doi.org/10.1029/2023tc008079","url":null,"abstract":"The interplay between regional tectonics and the development of a major ocean gateway between the Pacific and the Atlantic Ocean has resulted in numerous paleogeographic reconstruction studies that describe the Cenozoic tectonic history of the Scotia Sea region. Despite the multitude of published tectonic reconstructions and the variety of geological and geophysical data available from the Scotia Sea, the geological history remains ambiguous. We present a comparative paleogeographic analysis of previously published tectonic reconstructions to identify agreements and conflicts between these reconstructions. We propose an alternative model to explain the Cenozoic evolution of the Scotia Sea region. The paleogeographic comparison shows that most reconstructions agree on the tectonic evolution of the South Scotia Ridge and the East Scotia Ridge. Major differences between the reconstructions are the role of the westward subducting plate below the South Sandwich plate, and the age and origin of the Central Scotia Sea. Tectonic reconstructions assume that the Central Scotia Sea is either part of a Cenozoic back-arc basin, or a captured piece of Cretaceous oceanic crust. We propose a new alternative tectonic reconstruction that brings these two prevailing hypotheses elegantly together. Here, we identified new geographical blocks consisting of thinned continental or Cretaceous oceanic fragments that originate from the Paleo-Pacific Weddell Sea gateway from high-resolution bathymetry. These fragments are now part of the Central Scotia Sea and have been affected by early back-arc tectonic activity of the South Sandwich subduction zone, leading locally to the formation of Cenozoic-aged crust in the Central Scotia Sea.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"12 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

What Controls Early Restraining Bend Growth? Structural, Morphometric, and Numerical Modeling Analyses From the Eastern California Shear Zone 是什么控制了早期约束弯的生长？东加利福尼亚剪切带的结构、形态和数值模型分析

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-05-31 DOI: 10.1029/2023tc008148

Max M. Garvue, James A. Spotila, Michele L. Cooke, Elizabeth R. Curtiss

{"title":"What Controls Early Restraining Bend Growth? Structural, Morphometric, and Numerical Modeling Analyses From the Eastern California Shear Zone","authors":"Max M. Garvue, James A. Spotila, Michele L. Cooke, Elizabeth R. Curtiss","doi":"10.1029/2023tc008148","DOIUrl":"https://doi.org/10.1029/2023tc008148","url":null,"abstract":"Restraining bends influence topography, strike-slip evolution, and earthquake rupture dynamics, however the specific factors governing their geometry and development in the crust are not well established. These relationships are challenging to investigate in field examples due to cannibalization and erosion of earlier structures with cumulative strain. To address this knowledge gap, we investigated the structure, morphology, and kinematics of 22 basement-cored restraining bends on low net-slip faults (<10 km) within the southern Eastern California shear zone (SECSZ) via mapping, topographic analyses, and 3D numerical modeling. The bends are self-similar in form with most exhibiting focused relief between high-angle bounding faults with an arrowhead shape in map view and a “whaleback” longitudinal profile. Slight changes in that form occur with increasing size indicating predictable growth that appears to be primarily controlled by local fault geometries (i.e., bifurcation angle), rather than the influence of fault obliquity relative to far-field plate motion, due to inefficient slip-transfer across interconnected irregularly trending closely spaced faults. Modeling results indicate that the self-similar fault-bound geometry of SECSZ restraining bends may arise from elevated shear strain at the outer corners of single transpressional fault bends with increasing cumulative slip. This, in turn, promotes growth of a new fault leading to efficient accommodation of local convergent strain via uplift between bounding faults. Finally, our results indicate that the kilometer-scale restraining bends contribute minimally to regional contraction as they only penetrate the upper third of the seismogenic crust and are therefore also unlikely to impede large earthquake surface ruptures.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"50 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141191799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evolution of Arc-Continent Collision in the Southeastern Margin of the South China Sea: Insight From the Isugod Basin in Central-Southern Palawan 中国南海东南边缘弧-大陆碰撞的演变：巴拉望岛中南部伊苏戈德盆地的启示

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-05-31 DOI: 10.1029/2023tc008078

Wen-Huang Chen, Yi Yan, Andrew Carter, Peter D. Clift, Chi-Yue Huang, Graciano P. Yumul, Carla B. Dimalanta, Jillian Aira S. Gabo-Ratio, Le Zhang, Ming-Huei Wang, Xin-Chang Zhang

{"title":"Evolution of Arc-Continent Collision in the Southeastern Margin of the South China Sea: Insight From the Isugod Basin in Central-Southern Palawan","authors":"Wen-Huang Chen, Yi Yan, Andrew Carter, Peter D. Clift, Chi-Yue Huang, Graciano P. Yumul, Carla B. Dimalanta, Jillian Aira S. Gabo-Ratio, Le Zhang, Ming-Huei Wang, Xin-Chang Zhang","doi":"10.1029/2023tc008078","DOIUrl":"https://doi.org/10.1029/2023tc008078","url":null,"abstract":"The evolution of arc-continent collision between the Palawan microcontinental block and the Cagayan Ridge in the southeastern margin of the South China Sea (SCS) is vital to understand how this collision correlated with seafloor spreading of the SCS. To address the evolution of arc-continent collision, we studied the biostratigraphy and provenance of syn-collisional sediments in the Isugod Basin in central-southern Palawan. Microfossil analysis indicates a Late Miocene age (11.5–5.6 Ma) for the Isugod and Alfonso XIII Formations and rapid subsidence during initiation of the basin which may have been triggered by local extensional collapse of the wedge in response to forearc uplift. Multidisciplinary provenance analysis reveals that the Isugod and Alfonso XIII Formations were derived from the Middle Eocene–lower Oligocene Panas-Pandian Formation on the Palawan wedge and the Late Eocene Central Palawan Ophiolite. These results suggest the emergence of both the orogenic wedge and obducted forearc ophiolite at ∼11.5 Ma, implying collision onset before ∼11.5 Ma. The collision initiation in Palawan could be better constrained to ∼18 Ma, based on the drowning of the Nido carbonate platform in the foreland. Therefore, the gravitational collapse of the Palawan wedge and the subsidence/formation of the Isugod Basin might reflect a significant uplift pulse in the hinterland of the wedge beginning within 13.4–11.5 Ma in the late stage of collision. It indicates that although compression originated from spreading of the SCS had ceased at 16–15 Ma, arc-continent collision in Palawan did not stop and was sustained by compression from the upper plate afterward.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"36 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141191771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Switching From Subduction Zone Advance to Retreat Explains the Late Paleozoic Evolution of the East Junggar System, Central Asian Orogenic Belt 从俯冲带前进到后退的转换解释了中亚造山带东准噶尔系统的晚古生代演化

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-05-31 DOI: 10.1029/2024tc008254

Yazhou Miao, Jian Zhang, Karel Schulmann, Alexandra Guy, Igor Soejono, Yingde Jiang, Min Sun, Shuhui Zhang, Zhiyong Li

{"title":"Switching From Subduction Zone Advance to Retreat Explains the Late Paleozoic Evolution of the East Junggar System, Central Asian Orogenic Belt","authors":"Yazhou Miao, Jian Zhang, Karel Schulmann, Alexandra Guy, Igor Soejono, Yingde Jiang, Min Sun, Shuhui Zhang, Zhiyong Li","doi":"10.1029/2024tc008254","DOIUrl":"https://doi.org/10.1029/2024tc008254","url":null,"abstract":"The geodynamic evolution of the East Junggar is examined by means of satellite imaging and field-based structural studies, U-Pb zircon geochronology and analysis of potential field geophysical data in the Yemaquan arc and the Dulate back-arc systems. The northern Yemaquan arc shows a pervasive WNW–ESE steep S1 foliation that is related to the exhumation of Armantai ophiolitic mélange in an F1 antiformal structure. The bedding of the Dulate sequences is folded by N–S-trending F1 upright folds that are preserved in low strain domains. The timing of D1 is estimated between 310 and 280 Ma. During D2, previously folded Dulate sequences were orthogonally refolded by E–W-trending F2 upright folds, resulting in Type-1 basin and dome interference pattern and pervasive E–W trending S2 cleavage zones. The age of D2 is constrained to be 270–250 Ma based on the dating of syn-tectonic pegmatites and deposition of syn-orogenic sedimentary rocks. The boundary between the Yemaquan arc and Dulate back-arc basin experienced reactivation through D2 dextral transpressive shear zones. The D1 fabrics are the consequence of the closure of the Dulate back-arc basin due to the advancing mode of Kalamaili subduction. Almost orthogonal Permian D2 fabrics were generated by the N–S shortening of the East Junggar and the northward movement of the Junggar Block indenter. This D2 deformation was associated with the anticlockwise rotation of the southern limb of the Mongolian Orocline, the scissor-like closure of the northerly Mongol-Okhotsk Ocean and the collision of the Mongolian and the Tarim–North China craton collages.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"36 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141191797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Formation and Evolution of the Pacific-North American (San Andreas) Plate Boundary: Constraints From the Crustal Architecture of Northern California 太平洋-北美（圣安德烈斯）板块边界的形成与演化：北加利福尼亚地壳结构的制约因素

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-05-30 DOI: 10.1029/2023tc007963

Kevin P. Furlong, Antonio Villaseñor, Harley M. Benz, Kirsty A. McKenzie

{"title":"Formation and Evolution of the Pacific-North American (San Andreas) Plate Boundary: Constraints From the Crustal Architecture of Northern California","authors":"Kevin P. Furlong, Antonio Villaseñor, Harley M. Benz, Kirsty A. McKenzie","doi":"10.1029/2023tc007963","DOIUrl":"https://doi.org/10.1029/2023tc007963","url":null,"abstract":"The northward migration of the Mendocino triple junction (MTJ) drives a fundamental plate boundary transformation from convergence to translation; producing a series of strike-slip faults, that become the San Andreas plate boundary. We find that the 3-D structure of the Pacific plate lithosphere in the vicinity of the MTJ controls the location of San Andreas plate boundary formation. At the time of initiation of the Pacific-North America plate boundary (∼30 Ma), the sequential interaction with the western margin of North America of the Pioneer Fracture Zone, soon followed by the Mendocino Fracture Zone, led to the capture of a small segment of partially subducted Farallon lithosphere by the Pacific plate, termed the Pioneer Fragment (PF). Since that time, the PF has translated with the Pacific Plate along the western margin of North America. Recently developed, high-resolution seismic-tomographic imagery of northern California indicates that (a) the PF is extant, occupying the western half of the slab window, immediately south of the MTJ; (b) the eastern edge of the PF lies beneath the newly forming Maacama fault system, which develops to become the locus for the primary plate boundary structure after approximately 6–10 Ma; and (c) the location of the translating PF adjacent to the asthenosphere of the slab window generates a shear zone within and below the crust that develops into the plate boundary faults. As a result, the San Andreas plate boundary forms interior to the western margin of North America, rather than at its western edge.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"50 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141191772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Ancient Configuration of the Southern Central Andes and Paleogeographic Reconstruction of the Late Cretaceous Foreland Basin at 34°40’S 安第斯山脉中南部的古老构造与南纬 34°40'白垩纪晚期前陆盆地的古地理重建

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-05-27 DOI: 10.1029/2023tc008119

F. E. Martos, L. M. Fennell, M. Naipauer, V. Valencia, A. Folguera

{"title":"The Ancient Configuration of the Southern Central Andes and Paleogeographic Reconstruction of the Late Cretaceous Foreland Basin at 34°40’S","authors":"F. E. Martos, L. M. Fennell, M. Naipauer, V. Valencia, A. Folguera","doi":"10.1029/2023tc008119","DOIUrl":"https://doi.org/10.1029/2023tc008119","url":null,"abstract":"The early stages of Andean construction have been barely recognized due to a long history of tectonic superposition during the growth of the orogen. In this work, we present a multi-method approach integrating sedimentological, geochronological, structural, and provenance analyses to reconstruct the architecture of the Late Cretaceous foreland basin at 34°40’S. We identified a new depocenter located in an inner position of the Late Cretaceous foreland basin, a strategic location to understand the sedimentation dynamics near the topographic front of the orogen. Two sandstone samples from the basal and upper sections of the Diamante Formation were collected for detrital zircons dating, which yielded maximum depositional ages between 98 Ma and 91 Ma. The provenance analyses based on U-Pb zircons ages indicated a main source area located to the west, in the incipient orogenic belt, with a complementary contribution from basement rocks, located to the east. Moreover, growth strata documented in these deposits were compared with structural kinematic models, which suggest that some of these deposits are associated with inherited structures, reactivated during the tectonic inversion of the extensional Jurassic Atuel depocenter. Our paleogeographic model comprises an Andean Cordillera flanked by a hinterland basin to the west and a foreland basin to the east, with a deformational front positioned further east compared to previous models.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"19 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141173280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Salt Distribution in the South Pyrenean Central Salient: Insights From Gravity Anomalies 南比利牛斯山脉中盐的分布：重力异常的启示

IF 4.2 1区地球科学

Tectonics Pub Date : 2024-05-11 DOI: 10.1029/2024tc008274

P. Santolaria, C. Ayala, R. Soto, P. Clariana, F. M. Rubio, J. Martín-León, E. L. Pueyo, J. A. Muñoz

{"title":"Salt Distribution in the South Pyrenean Central Salient: Insights From Gravity Anomalies","authors":"P. Santolaria, C. Ayala, R. Soto, P. Clariana, F. M. Rubio, J. Martín-León, E. L. Pueyo, J. A. Muñoz","doi":"10.1029/2024tc008274","DOIUrl":"https://doi.org/10.1029/2024tc008274","url":null,"abstract":"Triassic evaporites represent the regional décollement of the Pyrenees and form two salt provinces north and south of the South Pyrenean Central Salient (SPCS). We present an updated Bouguer and residual Bouguer anomaly map built upon the homogenization of available gravity data of the SPCS together with four new and representative cross-sections, constrained by geological data acquired in the field, seismic, well, and gravity data (gravity forward modeling). Gravity anomaly maps and cross-sections are used to characterize the present-day uneven distribution of Triassic evaporites. Outcropping Triassic evaporites is not necessarily associated with an underlying evaporite accumulation and the absence of it at surface does not involves its non-existence at depth. Northwest of the salient, a major accumulation of Triassic evaporites floors a thick syn-orogenic Upper Cretaceous basin. South of it, Triassic rocks core salt-detached anticlines related to the Pyrenean orogeny. Along the southernmost (and youngest) thrust sheet of the salient, diapirs, and evaporite accumulations are associated with a salt-inflated area.","PeriodicalId":22351,"journal":{"name":"Tectonics","volume":"43 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140932033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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