Tajik Basin and Southwestern Tian Shan, Northwestern India-Asia Collision Zone: Timing of Basin Inversion and Associated Deformation-Field Evolution

塔吉克盆地和西南天山、西北印度-亚洲碰撞带：盆地反转的时间和相关的变形场演化

• 批准号: 433506869
• 负责人: Professor Dr. Lothar Ratschbacher
• 金额: --
• 依托单位: Institut für Geologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/433506869?language=en
• 关键词: Tajik; Basin; Southwestern; Tian; Shan

The Tajik basin and southwestern Tian Shan constitute the North-western tip of the India-Asia collision zone. Likely Oligocene-Neogene basin inversion formed the top-to-WNW, thin-skinned Tajik thrust-fold belt, outlined by westward convex fold trains, and underlain by a décollement in Jurassic evaporites. The southwestern Tian Shan constitutes the thick-skinned foreland buttress. The Tajik thrust-fold belt forms an asymmetric (rotational) extruding-gliding-spreading nappe, connecting Pamir-plateau crustal collapse with shortening in the Tajik-basin depression. Building on studies by my group, firstly we will develop a full understanding of the evolution of deformation during the inversion of the Tajik basin via a regional "paleostress" study. The outcome will be the establishment of a detailed relative deformation-field evolution, from early, rotated structural fabrics to late, un- or little-rotated ones; the latter should approximate/match today’s deformation field. Second, we will complement the existing thermochronologic database by dating additional samples using the apatite fission-track and (U-Th)/He methods. With this data, we will get a full, regional coverage of ages to interpret the time evolution of the inversion of the Tajik basin. Third, we aim to date the deformation history of the Tajik thrust-fold belt using U-Pb calcite geochronology, placing constraints on fault movements and tension-gash formation. Importantly, we will make use of the detailed analysis of the pre-, syn-, and post-folding stages of deformation and date faults and gashes related to this relative evolution. In addition, we will also select calcite from faults that indicate early and late stages in vertical axis rotation of fault-sets. The expected outcome is a basin-wide establishment of the onset of inversion and an understanding of the subsequent out-of-sequence reactivation in various parts of the basin.

塔吉克盆地和西南天山构成了印度 - 亚洲碰撞区的西北尖端。可能的渐新世中新世盆地盆地倒置形成了顶级薄皮的塔吉克推力折线，并由西部凸褶折列概述，并在侏罗纪蒸发岩中的脱衣舞下方。西南天山构成了皮肤厚实的前陆支柱。 Tajik推力折线带形成了不对称的（旋转）挤出滑行式尿布，将Pamir-Plateau Crustal Colustal Collapse连接到塔吉克 - 巴蛋白抑郁症中的缩短。在我小组的研究的基础上，首先，我们将通过区域“古剧院”研究在塔吉克盆地反转过程中对变形的演变有充分的了解。结果将是建立详细的相对变形场进化，从早期，旋转的结构织物到晚期，未旋转的结构织物；稍后的应大约/匹配今天的变形字段。其次，我们将使用磷灰石裂变轨道和（u-th）/HE方法来完成现有的热量数据库。借助这些数据，我们将获得年龄的完整，区域覆盖范围，以解释塔吉克盆地反转的时间演变。第三，我们旨在使用U-PB钙地质学的塔吉克推力折线皮带的变形历史记录，对故障运动和张力 - 刺激形成施加约束。重要的是，我们将利用与此相对演变相关的变形，日期断层和气体的固定阶段的详细分析。此外，我们还将从断层中指示早期和晚期的断层中选择方解石。预期的结果是跨盆地的建立，对倒置的发作以及对盆地各个地区随后的序列重新激活的理解。