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砾岩相通常作为构造事件的标志,对探讨造山带隆升过程有着重要的意义.选取位于帕米尔构造带东北缘的奥依塔格剖面开展砾石统计分析.新生代不同时期砾石的统计结果显示,奥依塔格剖面砾石成分主要为火成岩和变质岩,这与帕米尔造山带岩性相符.其中,花岗岩砾石作为特征组分首次出现在上新统阿图什组底部.砾石主要为巨砾,且以长短轴比值为1～2的近圆状为主;砾石的磨圆度中等,绝大部分为次磨圆-次棱角状;分选中等-差.结合砾石所处地层的沉积环境和热年代学记录,认为帕米尔东北缘新生代可能存在3期构造隆升事件,包括渐新-中新世克孜洛依组沉积早期、中新世中期(安居安组中-上段和帕卡布拉克组下段沉积时期)和上新世以来(阿图什组下段沉积以来).
Conglomerate facies is usually used as a sign of tectonic event, which is of great significance to explore the uplift process of orogenic belt.Ogatatag section located at the northeastern margin of the Pamir tectonic belt is used to conduct gravel statistical analysis.Statistics of gravel in different periods of the Cenozoic show , And the Oytaghi gravel is dominated by igneous and metamorphic rocks, which is consistent with the lithology of the Pamir orogenic belt, in which granite gravel first appeared in the bottom of the Pliocene Atushi Formation as the characteristic component.The gravels are mainly boulders , With the ratio of short axis to short axis of 1 ~ 2, and the gravel roundness is medium, most of which are sub-rounding-sub-angular, moderate to poor sorting, combined with the depositional environment of gravel And thermochronology records, it is suggested that there may be three tectonic uplift events in the Cenozoic of the northeastern margin of the Pamir, including the sedimentation of the Oligocene-Miocene Kiziloyai Formation, the mid-Miocene The Lower Cambrian Formation) and since the Pliocene (since the deposition of the lower part of the Atushi Formation).