首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Characteristics of Heavy Minerals and Quantitative Provenance Identification of Sediments from the Muddy Area Outside the Oujiang Estuary Since 5.8 kyr
Authors:Hongying Song  Jinqing Liu  Ping Yin  Yong Zhang  Xiaoying Chen
Institution:1.Center for Isotope Geochemistry and Geochronology,Qingdao National Laboratory for Marine Science and Technology,Qingdao,China;2.Key Laboratory of Marine Environmental Geology, Ministry of Natural Resources,Qingdao Institute of Marine Geology,Qingdao,China;3.Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology,Qingdao,China;4.College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao,China
Abstract:The heavy mineral compositions of the sediments in core D04 with a length of 20.2 m from the muddy area outside the Oujiang Estuary along the coast of Zhejiang-Fujian Provinces have been analyzed. Core D04 can be divided into three units: DU1 (0–7.4 m), DU2 (7.4–11.4 m) and DU3 (11.4–20.2 m). The results showed that the heavy minerals are authigenic pyrite (65.6%)–hornblende (16.0%)–epidote (4.6%) assemblages. The core sediments are mainly composed of clayey silt, which belongs to the clinoform deposit formed since 5.8 kyr, indicating a weak hydrodynamic environment. The deposition rates changed in the trend of high-low-high upward. Quantitative analysis shows that the core sediments were mainly from the suspended sediments of the Changjiang (Yangtze) River, accounting for 79.2%, with only 10.0% from Oujiang, and 10.8% from other provenance. The Oujiang-derived sediments were gradually increased from the bottom unit DU3 (3.1%) to the top unit DU1 (17.8%), but the Changjiang-derived sediments were gradually decreased. The source changes are closely related to the development of Yangtze River Delta and Wenzhou Bay, climate changes and human activities. During the period of 2.1–3.7 kyr, the sediment supply was greatly reduced due to the poor reclamation capacity of the river basins, resulting in a low deposition rate. Since 2 kyr, the enhancement of human activities in the Yangtze River Basin and the Oujiang River Basin led to more soils to be eroded and transported to the study area. Due to the short distance of the site of core D04 from the Oujiang River mouth, the study area received more Oujiang-derived sediments when upper unit (DU1) deposited than the lower units (DU2 and DU3).
Keywords:
本文献已被 CNKI SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号