伊犁盆地南缘隆升剥蚀及其盆地南部的沉积响应——利用磷灰石裂变径迹分析

分析了伊犁盆地南缘蚀源区14件磷灰石样品，其中南缘中西部10件，东部4件。磷灰石裂变径迹表观年龄及其与高程的关系、单颗粒年龄、封闭径迹分布特征表明，伊犁盆地南缘样品均遭受了不同程度的退火，但没有发生明显的区域性热事件。通过封闭径迹正演热史模拟得出，伊犁盆地南缘中新生代构造演化经历了三叠纪-侏罗纪晚期快速隆升，白垩纪-古近纪相对稳定和新构造快速隆升三个阶段。东西两段略有不同，西段隆升时间较早，样品所在地在早三叠世就开始强烈隆升，说明当时该处离原型盆地边界较近，而东段此时样品所在位置还可能接受沉积，直至中侏罗世末期才开始隆升剥蚀。侏罗纪原型盆地南部边界至少跨过大板煤矿，因为在该处出露中侏罗世西山窑组残留地层。相应的稳定阶段东段要滞后一些，稳定时间相对较短，西段该时段长达100Ma，而东段多在50～60Ma。新构造运动强烈活动的时间东段相对较早，局部地段在38Ma就开始隆升。盆地南缘沉积相带的发育特征和新近纪（或第四纪）内给出的电子自旋共振年龄（ESR）均说明，沉积对构造具明显的响应，盆缘快速隆升阶段其盆地内相应的沉积物较粗，相对稳定阶段对应的沉积较细或缺失。

Uplift-denudation in the south margin and its sedimentary response in the southern Yili basin:Analysis apatite fission track method

14 apatite samples,of which 10 samples were collected in the midwest segment and 4 samples were collected in the east segment,are analyzed from the south denudation area of Yili basin.The characteristics of apparent age and its relationship with altitude,single grain age,confined fission-track length distribution of apatite fission track show that these samples have annealinged in some extent but have not suffered from obvious regional thermal event.The simulation of normal thermal history by confined fissi...