和静逆断裂-褶皱带的第四纪构造地貌与侧向扩展  

MORPHOTECTONIC EVIDENCE FROM LATERAL PROPAGATION OF HEJING REVERSE FAULT-FOLD ZONE DURING THE LATE QUATERNARY

作　　者：黄伟亮[1] 杨晓平[1] 李安[1] 张玲[1] 

机构地区：[1]中国地震局地质研究所,国家地震活动断层研究中心,北京100029

出　　处：《地震地质》2011年第4期765-776,共12页Seismology and Geology

基　　金：国家自然科学基金(40572126);财政部重大专项“我国地震重点监视防御区活动断层地震危险性评价”;地震行业科研专项(200808013)共同资助

摘　　要：位于天山南麓焉耆盆地北缘的和静逆断裂-褶皱带是天山地区的一个最新的变形带。通过对褶皱带西段夏尔木登背斜、哈尔莫顿背斜区遥感卫星影像(ETM+)和分辨率为25m的数字高程模型(DEM)数据解译分析,并结合野外考察,对两个背斜的地形横剖面、纵剖面,水系发育特征,两翼11个小型汇水盆地的水系密度、面积高度曲线和积分值分析表明,夏尔木登背斜和哈尔莫敦背斜在第四纪时期发生了隆升,而且夏尔木登背斜先于哈尔莫敦背斜开始隆升。夏尔木登背斜自中部向东西两侧扩展,哈尔莫敦背斜则自西向东扩展。第四纪构造活动是驱动横穿两个背斜的一系列河流向东迁移的驱动因素,并形成一系列自西向东谷底高程逐渐降低的风口。夏尔木登背斜两翼汇水盆地的河流水系密度自中部由5.37km-1分别向东西两侧降低到2.65km-1和3.07km-1,盆地内的冲沟坡度角也逐渐由中部向两侧变陡。而哈尔莫敦背斜表现出以垂向的构造隆起和向东的侧向生长为主的变形模式,水系密度自西向东逐渐降低,由3.87km-1降低到2.37km-1,冲沟坡度角由4°上升到6°,面积高度曲线由S形逐渐变为向上凸起,积分值也由0.45增加到0.76。此外,自西向东横穿背斜的11条地形横剖面指示了褶皱的高度由西向东逐渐递减,也证明了和静逆断裂-褶皱带整体自西向东的侧向扩展变形。The Hejing reverse fault-fold zone locates on the northern margin of the Yanqi Basin which lies in the south Tianshan Mts.The zone has been growing since early-Quaternary till now.The Xiaermudeng and Haermodun anticlines in the western of Hejing reverse fault-fold are discussed in this paper.Based on the analysis of satellite images and DEM（digital elevation model）data with the spatial resolution of 25m as well as field observation,our results suggest that the Xiaermudeng and Haermodun anticlines have uplifted and propagated laterally during the late Quaternary.Stream-flow direction,topographic sections,decrease of elevation of wind gap and hypsometric analysis indicate that Xiaermudeng anticline uplifted preceding the Haermodun anticline.We also believe that the Xiaermudeng anticline grows laterally from middle to side and Haermodun anticline grows laterlally from west to east.The flows crossing the anticline have diverted eastward under the tectonic movement during the Quaternary,producing a series of wind gaps with straths lowering from west to east.In the Xiaermudeng anticline area,from middle to the side,the drainage density（Dd）is decreased（5.37km-1 to 2.65km-1 and 3.07km-1）,and the slope of catchment is increased.The anticline of Haermodun shows a main deformation pattern of uplift and lateral propagation from west to east.The drainage density is decreased（3.87km-1 to 2.37km-1）,the catchment has steep slope（4° to 6°）,the hypsometric curve is from concave-convex to concave-down and the hypsometric integral（∫） is increased（0.45 to 0.76）,Moreover,11 topographical cross-sections transecting the anticlines also reveal the lateral propagation from west to east of the Hejing reverse fault-fold zone.

关 键 词：第四纪 褶皱隆升 侧向扩展 面积高度曲线 焉耆盆地 天山 

分 类 号：P315.2[天文地球—地震学]