Pattern and timing of late Cenozoic rapid exhumation and uplift of the Helan Mountain, China
Pattern and timing of late Cenozoic rapid exhumation and uplift of the Helan Mountain, China
复制标题
DOI：
10.1007/s11430-010-0016-0
复制
发表时间：
2010-03
期刊：
影响因子：
--
通讯作者：
Jian-Hui Liu;Peizhen Zhang;D. Zheng;Jinlin Wan;Weitao Wang;P. Du;Q. Lei
中科院分区：
文献类型：
--
作者：
Jian-Hui Liu;Peizhen Zhang;D. Zheng;Jinlin Wan;Weitao Wang;P. Du;Q. Lei
贺兰山位于中国南北地震带的北方，鄂尔多斯地块西北缘，是华北板块内的一条板内变形带。贺兰山新生代的变形历史表现为沿贺兰山东段断裂沿着伸展，导致贺兰山相对于邻近银川盆地的裂陷而折返隆升。在这里，我们提出了新的磷灰石裂变径迹（AFT）数据从几个断面相邻的EHSF在中部和北方贺兰山。贺兰山北方（大武口和正义关断面）的AFT年龄介于10 ~ 89 Ma之间，而贺兰山南部（苏峪口断面）的AFT年龄大于71 Ma。AFT数据分析揭示贺兰山在10-12 Ma开始快速隆升和折返。此外，AFT年龄与其平均径迹长度的曲线图显示了一个独特的“回飞棒”模式，表明贺兰山经历了一个离散的加速折返阶段开始于10-12 Ma。在空间上，AFT样品系统地增加年龄远离EHSF和晚新生代折返是缓慢的贺兰山西南部和东北部贺兰山快速，以及更快的EHSF附近和更慢远离EHSF一致。晚新生代折返的空间分布表明，东秦岭正断裂活动与贺兰山10-12 Ma以来的南西向隆升和快速折返有关。贺兰山的隆升与折返是鄂尔多斯地块西北缘在新生代晚期强烈伸展作用的响应，是在沿银川-吉兰台-河套和毗邻鄂尔多斯地块的渭河-山西地堑系的北西-南东沿着向的区域伸展应力场作用下发生的。
The Helan Mountain, an intraplate deformation belt in the North China Craton, is located in the northern portion of the China North-South seismic belt, and at the northwestern margin of the Ordos Block. The Cenozoic deformation history of the Helan Mountain is characterized by extension along the eastern Helan Mountain fault (EHSF), resulting in the exhumation and uplift of the Helan Mountain, relative to the rifting of the adjacent Yinchuan Basin. Here we present new apatite fission track (AFT) data from several transects adjacent to the EHSF in the central and northern Helan Mountain. AFT ages from the northern Helan Mountain (Dawukou and Zhengyiguan transects) range from 10 Ma to 89 Ma, whereas AFT ages from the southern Helan Mountain (Suyukou transect) are greater than 71 Ma. The AFT data analysis reveals initiation of rapid uplift and exhumation of the Helan Mountain at 10–12 Ma. Additionally, a plot of the AFT ages versus their mean track length shows a distinctive “boomerang” pattern indicating that the Helan Mountain experienced a discrete phase of accelerated exhumation beginning at 10–12 Ma. Spatially, AFT samples systematically increase in age away from the EHSF and are consistent with late Cenozoic exhumation that was slow in the southwestern Helan Mountain and rapid in the northeastern Helan Mountain, as well more rapid adjacent to the EHSF and slower away from the EHSF. Obviously, the spatial distribution of late Cenozoic exhumation indicates that normal faulting of the EHSF is related to southwestward tilting and rapid exhumation of the Helan Mountain beginning at 10–12 Ma. The uplift and exhumation of the Helan Mountain was a response to the intensive extension of the northwestern margin of the Ordos Block in the late Cenozoic; this occurred under a regional extensional stress field oriented NW-SE along the Yinchuan-Jilantai-Hetao and the Weihe-Shanxi graben systems adjacent to the Ordos Block.