| 查看: 318 | 回复: 0 | |||
hanwuji木虫 (职业作家)
|
[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
长江大学石油工程学院佘跃惠团队招收2025年9月入学的博士研究生
已经有2人回复
-
祈福，祝自己今年好运
已经有100人回复
-
地质学论文润色/翻译怎么收费?
已经有206人回复
-
关于会评
已经有1人回复
-
据说！出现这些情况，国基金会评本子会被拿下！
已经有19人回复
-
无人打捞，直接陪跑
已经有16人回复
-
定了定了，明天出结果！2025 国自然基金结果即将揭晓，查询攻略看这里
已经有107人回复
-
2025国家自然科学基金放榜时间，根据官方回应，8月15日基本没戏了
已经有5人回复
-
各位未来院士帮忙看看评审意见
已经有9人回复
-
【招聘】科研助理+五险一金
已经有18人回复
-
《风吹过日常的缝隙》
已经有0人回复
