西天山中新生代隆升剥露的裂变径迹证据

发布时间：2018-03-29 22:18

本文选题：裂变径迹　切入点：隆升-剥露　出处：《东华理工大学》2017年硕士论文

【摘要】：中新生代在新疆不同的构造单元中,都存在着隆升-剥露事件。本文主要是研究西南天山和西天山中段的隆升剥露历史,使用磷灰石裂变径迹定年技术,结合温度-时间来反演隆升剥露的过程。本文中的16个样品分别采自西南天山霍什布拉克和巴雷公岩体以及西天山中段的独库公路附近的花岗岩体。西南天山裂变径迹测试结果显示,样品的径迹年龄介于63.2±4.7~67.6±4.3Ma,平均径迹长度介于13.54±0.11~14.15±0.09μm之间,西天山中段裂变径迹测试结果表明,样品的径迹年龄介于48.8±3.1~81.6±4.9Ma,平均径迹长度介于12.72±0.17~13.73±0.14μm之间。在时间上,西南天山样品记录的快速隆升的时间主要集中在65~80Ma之间,西天山中段样品记录的快速隆升时间主要集中在70~90Ma之间,两地在新生代10Ma至今也都经历了一次快速隆升事件,而且图中表明现在仍在隆升期间。综合对应的地质证据,推断出西南天山-西天山中段地区从晚白垩世开始出现差异隆升剥露的现象。这种隆升-剥露事件的动力学机制并不是单一控制的,一般都为多种原因综合控制,导致差异隆升剥露的主要原因可能是不同块体之间的相互碰撞挤压作用和天山不同地段的热-流变性质的差异性。但新生代整体隆升的动力学机制尚不明确,仍有待学者进一步研究。
[Abstract]:Uplift and exfoliation occurred in different tectonic units of Xinjiang in Mesozoic and Cenozoic. This paper mainly studies uplift and exfoliation history of southwest Tianshan and western Tianshan, and uses apatite fission track dating technique. In this paper, 16 samples were collected from the Hoseblak and Barragon pluton in the southwest Tianshan and the granite bodies near the Duku highway in the middle of the western Tianshan mountain, respectively. The rift of the southwest Tianshan mountain. Variable track tests show that, The track age of the sample was 63.2 卤4.7 卤4.3 Ma.The average track length was between 13.54 卤0.1114.15 卤0.09 渭 m. The results of fission track test showed that the age of the fission track was between 48.8 卤3.1 and 81.6 卤4.9 Ma, and the average track length was between 12.72 卤0.1713.73 卤0.14 渭 m. The time of rapid uplift recorded in southwest Tianshan is mainly between 65~80Ma, while in the middle of West Tianshan, the time of rapid uplift is mainly between 70~90Ma. The two places have also experienced a rapid uplift event in Cenozoic 10Ma. And the map shows that it is still during the uplift. Combined with the corresponding geological evidence, It is inferred that the differential uplift and exfoliation began to occur in the middle part of the southwest Tianshan-West Tianshan Mountains from the late Cretaceous. The dynamic mechanism of this uplift and exfoliation event is not only controlled by a single control, but generally controlled by a variety of reasons. The main causes of differential uplift and exfoliation may be the collision and squeezing of different blocks and the difference of thermo-rheological properties in different sections of Tianshan Mountain, but the dynamic mechanism of the whole uplift of Cenozoic is not clear. Further research is still needed.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P542

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