Denudation History of South China Block and Sediment Supply to Northern Margin of the South China Se

来源 :Journal of Earth Science | 被引量 : 0次 | 上传用户:tyycyf
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
On the basis of apatite fission track (AFT) analyses, this article aims to provide a quanti-tative overview of Cenozoic morphotectonic evolution and sediment supply to the northern margin of the South China Sea (SCS). Seventeen granite samples were collected from the coast to the inland of the South China block. Plots of AFT age against sample location with respect to the coastline show a gen-eral trend of youngling age away from the coast, which implies more prolonged erosion and sediment contribution at the inland of the South China Sea during post break-up evolution. Two-stage fast ero-sion process, Early Tertiary and Middle Miocene, is deduced from simulated cooling histories. The first fast cooling and denudation during Early Tertiary are recorded by the samples along the coast (between 70 and 60 Ma) and the inland (between 50 and 30 Ma), respectively. This suggests initial local erosion and deposition in the northern margin of the SCS during Early Tertiary. Fast erosion along the coast ceased since ca. 50 Ma, while it had lasted until ca. 30 Ma inland, indicating that the erosion was trans-ferred from the local coastal zone initially toward the continental interior with unified subsidence of the northern margin, which resulted in the formation of a south-dipping topography of the continental margin. The thermal stasis in the South China block since ca. 30 Ma must define the time at which the northern margin became dynamically disconnected from the active rifting and stretching that was tak-ing place to the south. The lower erosion rate is inconsistent with higher sedimentary rate in the Pearl River Mouth basin during Late Oligocene (ca. 25 Ma). This indicates that the increased sedimentation in the basin is not due to the erosion of the granite belt of the South China block, but perhaps points to the westward propagation of the paleo-Pearl River drainage related to the uplift of the eastern marginof Tibet plateau and southward jumping of spreading axis of the South China Sea. The sec-ond erosion acceleration rate of the Middle Miocene (ca. 14 Ma) cooling could have been linked to the long-distance effect of uplift of the Tibet plateau or due to the enhanced East Asian monsoon. On the basis of apatite fission track (AFT) analyzes, this article aims to provide a quanti-tative overview of Cenozoic morphotectonic evolution and sediment supply to the northern margin of the South China Sea (SCS). Seventeen granite samples were collected from the coast to the inland of the South China block. Plots of AFT age against sample location with respect to the coastline show a gen-eral trend of youngling age away from the coast, which implies more prolonged erosion and sediment contribution at the inland of the South China Sea during post break-up evolution. Two-stage fast ero-sion process, Early Tertiary and Middle Miocene, is deduced from simulated cooling histories. The first fast cooling and denudation during Early tertiary are recorded by the samples along the coast (between 70 and 60 Ma) and the inland (between 50 and 30 Ma), respectively. This suggests initial local erosion and deposition in the northern margin of the SCS during Early Tertiary. coast ceased since ca. 50 Ma, while it had lasted until ca. 30 Ma inland, indicating that the erosion was trans-ferred from the local coastal zone initially toward the continental interior with unified subsidence of the northern margin, which resulted in the formation of a south-dipping topography of the continental margin. The thermal stasis in the South China block since ca. 30 Ma must define the time at which the northern margin was dynamically disconnected from the active rifting and stretching that was tak-ing place to the South. The lower erosion rate is inconsistent with higher sedimentary rate in the Pearl River Mouth basin during Late Oligocene (ca. 25 Ma). This indicates that the increased sedimentation in the basin is not due to the erosion of the granite belt of the South China block, but perhaps points to the westward propagation of the paleo-Pearl River drainage related to the uplift of the eastern marginof Tibet plateau and southward jumping of spreading axis of theSouth China Sea. The sec-ond erosion acceleration rate of the Middle Miocene (ca. 14 Ma) cooling could have been linked to the long-distance effect of uplift of the Tibet Plateau or due to the enhanced East Asian monsoon.
其他文献
赠产品媒体报道口碑传“非典”疫情爆发了,公司研制生产的消毒杀菌机有了市场新卖点:一是政府要求公共场所和交通工具一律要有消毒措施;二是居民整天出门时提心吊胆,恐怕沾
中央对“三农”工作和供销社的高度重视,为处于改革发展关键时期的供销社提供了新的发展机遇,同时也对我们的工作提出了新的更高的要求。要适应新时期农村全面建设小康社会的要
由美国健康新科技股份有限公司研发的 AHET 营养食品活维素内含单一成分——山芋皂甙是从野生山芋中提取,没有任何其他附加成分。经常性补充活维素可以增加体能体力和肌肉,
中华全国供销合作总社党组书记周声涛同志,前不久到浙江进行调研,了解到该省市场经济比较发达、城镇化进程居全国之先的绍兴县,供销合作事业充满生机和活力,感到十分欣慰。周
2003年全省供销社的工作目标和任务已经明确,工作成果的好坏,关键取决于我们抓落实的力度。振奋精神,坚定发展供销社事业的信心。当前供销社尽管包袱沉重,工作面临诸多困难,但这只是前
“你决定了吗?该不是开玩笑吧!”1995年,身为安徽阜阳某事业单位办公室主任的黄俊岩毅然辞职下海,遭来身边人的一致反对,“人家下海,你也下海,可是你看看你选的方向,签名?就
1.慎重选项不要哪热闹往哪挤小本经营者,求稳心理较重,往往随帮轰,抱着别人做啥我做啥,走一条无风险、稳赚钱的经营之路的心理。然而,此路是走不通的。趁热投资的小本经营者
套管在井下发生脱扣失效事故之后通常要采用测井方法确定失效位置和失效形式。经过对多口井CBL、VDL和CCL套管测井结果进行了调查研究和分析,发现API接箍式偏梯形螺纹接头套
请下载后查看,本文暂不支持在线获取查看简介。 Please download to view, this article does not support online access to view profile.
当前中职生自杀、犯罪现象屡屡出现,迈进中职学校的学生多是初中时期的弱势群体,学习成绩差,长期受忽视,因此,培养学生的自尊、自信,让学生意识到并努力实现自己的生命价值,