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东安纳托利亚断层和安纳托利亚板块的形成
作者:小柯机器人 发布时间:2023/5/19 9:48:38

美国明尼苏达大学Donna L. Whitney的研究团队在研究东安纳托利亚断层、安纳托利亚板块和构造逃逸系统的形成方面取得新成果。相关论文于2023年5月16日发表在《地质学》杂志上。

东安纳托利亚断层带(EAFZ)附近岩石圈结构的热年代学数据和地震图像,为新板块和逃逸系统的发展提供了见解。研究人员称,东安纳托利亚断层带及其附近岩石的低温热年代学年龄明显比该地区其他断裂带年轻,例如,磷灰石(U-Th) /He:11-1 Ma对27-13 Ma。年轻磷灰石(U-Th) /He年龄和热历史模拟记录了过去约5 m.y 来沿东安纳托利亚断层带的热重置,因为它形成了贯穿岩石圈的结构,被解释为指示东安纳托利亚断层带中走滑断层触发的热活动。

从大陆动力学-中央安纳托利亚构造(CD-CAT)地震实验的S波速度图像中可以看出东安纳托利亚断层带形成的机制。这些图像表明,薄而坚固的阿拉伯岩石圈地幔在安纳托利亚地壳下向北延伸了约50-150km,并且可能位于ca.5 Ma的比特里斯-扎格罗斯缝合带(与研究区域的东安纳托利亚断层带位于同一位置)的当前地表位置的附近。坚固的阿拉伯岩石圈的俯冲促进了欧亚大陆边缘带的局部化,从而对安纳托利亚板块和逃逸系统的形成起着根本性的控制作用。

据介绍,自板块构造开始以来,岩石圈碎片响应碰撞(逃逸构造),沿走滑断层的横向运动具有汇聚背景的特征,并且也是新板块形成的一种机制。安纳托利亚板块是在≥10 m.y.的分布变形后,由走滑断层的顺序连接形成的,最终定位于板块边界断层。

附:英文原文

Title: Breaking plates: Creation of the East Anatolian fault, the Anatolian plate, and a tectonic escape system

Author: Donna L. Whitney, Jonathan R. Delph, Stuart N. Thomson, Susan L. Beck, Gilles Y. Brocard, Michael A. Cosca, Michael H. Darin, Nuretdin Kaymakc, Maud J.M. Meijers, Aral I. Okay, Bora Rojay, Christian Teyssier, Paul J. Umhoefer

Issue&Volume: 2023-05-16

Abstract: Lateral movement of lithospheric fragments along strike-slip faults in response to collision (escape tectonics) has characterized convergent settings since the onset of plate tectonics and is a mechanism for the formation of new plates. The Anatolian plate was created by the sequential connection of strike-slip faults following ≥10 m.y. of distributed deformation that ultimately localized into plate-bounding faults. Thermochronology data and seismic images of lithosphere structure near the East Anatolian fault zone (EAFZ) provide insights into the development of the new plate and escape system. Low-temperature thermochronology ages of rocks in and near the EAFZ are significantly younger than in other fault zones in the region, e.g., apatite (U-Th)/He: 11–1 Ma versus 27–13 Ma. Young apatite (U-Th)/He ages and thermal history modeling record thermal resetting along the EAFZ over the past ~5 m.y. and are interpreted to indicate thermal activity triggered by strike-slip faulting in the EAFZ as it formed as a through-going, lithosphere-scale structure. The mechanism for EAFZ formation may be discerned from S-wave velocity images from the Continental Dynamics–Central Anatolian Tectonics (CD-CAT) seismic experiment. These images indicate that thin but strong Arabian lithospheric mantle extends ~50–150 km north beneath Anatolian crust and would have been located near the present surficial location of the Bitlis-Zagros suture zone (co-located with the EAFZ in our study area) at ca. 5 Ma. Underthrusting of strong Arabian lithosphere facilitated localization of the EAFZ and thus was a fundamental control on the formation of the Anatolian plate and escape system.

DOI: 10.1130/G51211.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G51211.1/623411/Breaking-plates-Creation-of-the-East-Anatolian

期刊信息

Geology:《地质学》,创刊于1973年。隶属于美国地质学会,最新IF:6.324
官方网址:https://pubs.geoscienceworld.org/geology
投稿链接:https://geology.msubmit.net/cgi-bin/main.plex