Geotectonics最新文献_第5页

Digital Models of the Deep Structure of the Earth’s Crust in the Eurasian Basin of the Arctic Ocean 北冰洋欧亚盆地地壳深层结构数字模型

IF 1.1 4区地球科学

Geotectonics Pub Date : 2023-12-01 DOI: 10.1134/s0016852123070051

{"title":"Digital Models of the Deep Structure of the Earth’s Crust in the Eurasian Basin of the Arctic Ocean","authors":"","doi":"10.1134/s0016852123070051","DOIUrl":"https://doi.org/10.1134/s0016852123070051","url":null,"abstract":"<span> <h3> <strong>Abstract</strong>—</h3> <p>Digital models of the deep structure of the Earth’s crust are developed based on the method of gravity modeling, taking the accumulated geophysical data on the Eurasian Basin of the Arctic Ocean into account. The digital models of the basement relief and sedimentary cover thickness in the Eurasian Basin are calculated on the basis of reinterpretation of depth multi-channel reflection seismic cross-sections and 2D gravity modeling. The digital models of the Moho surface relief and the thickness of the Earth’s crust are calculated using the improved 3D gravity modeling method. It is shown that the reason for the deepening of the basement in the Nansen Basin by 1–1.5 km in comparison with the Amundsen Basin is a larger volume of accumulated sedimentary cover in the Nansen Basin, with a similar crustal thickness of ~4.8 km in both basins. The characteristics of the oceanic crust studied on the basis of the obtained digital models reveal a complex 3D variability typical of ultraslow spreading ridges. In the region of the Gakkel Ridge, which was formed at full rates of spreading of less than 12 mm/year, the maximum spread of crustal thicknesses occurs and the tectonic factor dominates over the magmatic one during the accretion of the oceanic crust. This manifests itself in the formation of extended submarine ridges parallel to the amagmatic segments of the ridge.</p> </span>","PeriodicalId":55097,"journal":{"name":"Geotectonics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140097683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Tectonic Implication and Geometry of the Minor Folds in Qaiwan and Goizhah Anticlines, Northeast of Sulaimani District, Northeastern Iraq 伊拉克东北部苏莱曼尼地区东北部柴湾和戈伊扎背斜小褶皱的构造意义和几何构造

4区地球科学

Geotectonics Pub Date : 2023-10-19 DOI: 10.1134/s0016852123050035

S. H. S. Al-Hakari

引用次数: 0

Neotectonic Indications in Iraq (North of the Arabian Plate): Analytical Overview 伊拉克(阿拉伯板块以北)新构造指示:分析综述

4区地球科学

Geotectonics Pub Date : 2023-10-19 DOI: 10.1134/s0016852123050060

V. K. Sissakian, A. A. Ghafur, L. H. Abdullah, N. Al-Ansari, J. Laue

引用次数: 0

Tectonically Stable Parts in Iraq Are Not Stable 伊拉克构造稳定的部分并不稳定

4区地球科学

Geotectonics Pub Date : 2023-10-19 DOI: 10.1134/s0016852123050072

V. K. Sissakian, N. A. Al-Ansari, L. H. Abdullah, J. Laue

{"title":"Tectonically Stable Parts in Iraq Are Not Stable","authors":"V. K. Sissakian, N. A. Al-Ansari, L. H. Abdullah, J. Laue","doi":"10.1134/s0016852123050072","DOIUrl":"https://doi.org/10.1134/s0016852123050072","url":null,"abstract":"Abstract Iraq is located in the extreme northeastern part of the Arabian Plate, which is in collision with the Iranian (Eurasian) Plate. The collision, which is still ongoing has created tens of folds some of which exhibit different types of faults. The exerted compressional forces are believed to be decreasing southwestwards as being far from the collision area (Suture Zone). Accordingly, all the existing tectonic and geological maps compiled by different authors and all the existing published articles, reports and books have considered two main tectonic domains in Iraq. The Stable Shelf and Unstable Shelf or Inner Platform and Outer Platform. The contact between these two main divisions follows almost the Euphrates River; towards the west of the river is the tectonically Stable area and towards the east and north is the tectonically Unstable area, which means the presence of different structural forms. In the current study, we have recognized tens of different Neotectonic evidence in the Stable part indicating that the area is tectonically not stable. Among those indications are abandoned valleys, development of sinkholes along certain lineaments, bending of valleys in right angles, and development of nick-points in valleys along certain lineaments.","PeriodicalId":55097,"journal":{"name":"Geotectonics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135729407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Oceanic Crust Formation in the Mid-Atlantic Ridge Segment between Azores and Icelandic Plumes: Results of Geological and Petrogeochemical Studies 亚速尔群岛和冰岛羽流之间的大西洋中脊部分的洋壳形成：地质和岩石地球化学研究结果

IF 1.1 4区地球科学

Geotectonics Pub Date : 2023-10-01 DOI: 10.1134/s0016852123050084

{"title":"Oceanic Crust Formation in the Mid-Atlantic Ridge Segment between Azores and Icelandic Plumes: Results of Geological and Petrogeochemical Studies","authors":"","doi":"10.1134/s0016852123050084","DOIUrl":"https://doi.org/10.1134/s0016852123050084","url":null,"abstract":"<span> <h3>Abstract</h3> <p>The structure of the ocean floor and the composition of basalts and dolerites of the MAR segment between the Maxwell and Charlie Gibbs FZs (North Atlantic) were studied based on the data obtained during the 53rd cruise of the R/V <em>Akademik Nikolaj Strakhov</em> organized and performed by the Geological Institute of the Russian Academy of Sciences over the period of July 7–August 15, 2022. In this segment, areas of greater and lesser magmatic productivity, which correspond to higher and lower bottom relief, alternate along the spreading axis. In high-relief areas, spreading cells form in the axial zone, and rises of tectonic and volcanic genesis dominate in the crest zone. In low-relief areas, the rift valley consists of deep rift basins; low ridges are developed on the flanks, which are separated by wide depressions. Oceanic N- and T-type tholeiites and E-MORB-type basalts and dolerites are distinguished among the studied volcanics. The N-tholeiites are widespread and were derived from mainly depleted mantle (source of DM). E-MORB-type basalts and dolerites are found in high-relief areas. Their mantle substrate is formed by a mixture of DM and EM-2 material with the subordinate role of HIMU. T-MORB volcanics are mainly localized on large volcanic rises in the southern part of the studied MAR segment and were melted from a substrate formed by a mixture of DM and HIMU material with the subordinate role of EM-2. Two types of mantle inhomogeneities involved in melting are reconstructed: passive and active. The former are represented by blocks of the transformed continental lithosphere that are similar in composition to the EM-2 mantle source. Active inhomogeneities associate with the uplift near Maxwell FZ of the microplume of the enriched mantle with a composition close to HIMU and with its subaxial flow in the north direction up to the Charlie Gibbs FZ.</p> </span>","PeriodicalId":55097,"journal":{"name":"Geotectonics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139409474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Morphotectonic Analysis of Sub-Basins along the North Termination of Anar Fault, Yazd Block, Iran 伊朗亚兹德地块阿纳尔断裂北端次盆地形态构造分析

IF 1.1 4区地球科学

Geotectonics Pub Date : 2023-08-29 DOI: 10.1134/s0016852123040076

E. Gholami, P. Vaghari, M. Khatib, A. Faghih

引用次数: 1

Basement Faults Effect on the Folding Style: A Case Study from Hendurabi Fault, Zagros, Iran 基底断裂对褶皱样式的影响——以伊朗扎格罗斯地区亨杜拉比断裂为例

IF 1.1 4区地球科学

Geotectonics Pub Date : 2023-08-29 DOI: 10.1134/s0016852123040064

S. Ghalandari, Z. Maleki, M. Arian, A. Solgi, M. Aleali

引用次数: 0

Extension Magnitude and Ratio of Central and South Segments in South Atlantic Margins 南大西洋边缘中南段的伸展幅度和比率