| 查看: 374 | 回复: 0 | |||
[交流]
Direct stratigraphic dating of India-Asia collision onset at 59 ± 1 Ma
|
|
Xiumian Hu Eduardo Garzanti Ted Moore sabella Raffi ABSTRACT The collision of India with Asia had a profound influence on Cenozoic topography, oceanography, climate, and faunal turnover. However, estimates of the time of the initial collision, when Indian continental crust arrived at the Transhimalayan trench, remain highly controversial. Here we use radiolarian and nannofossil biostratigraphy coupled with detrital zircon geochronology to constrain firmly the time when Asian-derived detritus was first deposited onto India in the classical Sangdanlin section of the central Himalaya, which preserves the best Paleocene stratigraphic record of the distal edge of the Indian continental rise. Deepsea turbidites of quartzarenite composition and Indian provenance are replaced upsection by turbidites of volcano-plutoniclastic composition and Asian provenance. This sharp transition occurs above abyssal cherts yielding radiolaria of Paleogene radiolarian zones (RP) 4–6 and below abyssal cherts containing radiolaria of zone RP6 and calcareous shales with nannofossils of the Paleocene calcareous nannofossil zone (CNP) 7, constraining the age of collision onset to within the middle Paleocene (Selandian). The youngest U-Pb ages yielded by detrital zircons in the oldest Asia-derived turbidites indicate a maximum depositional age of 58.1 ± 0.9 Ma. Collision onset is thus mutually constrained by biostratigraphy and detrital zircon chronostratigraphy as 59 ± 1 Ma. This age is both more accurate and more precise than those previously obtained from the stratigraphic record of the northwestern Himalaya, and suggests that, within the resolution power of current methods, the India-Asia initial collision took place quasi-synchronously in the western and central Himalaya |
回复此楼» 猜你喜欢
城乡规划学招收调剂 1名
已经有1人回复
-
首次在隐伏矿体上方发现金、硫酸铅、硝酸铅、三氧化钨等含金属纳米微粒
已经有8人回复
-
地球化学论文润色/翻译怎么收费?
已经有129人回复
-
求助：有没有大神有流体包裹体计算软件
已经有1人回复
-
【招聘】科研助理+五险一金
已经有868人回复
-
282求调剂
已经有0人回复
-
招聘博士研究生
已经有45人回复
