冲绳海槽北部西坡的古三角洲沉积

来源 :海洋科学集刊 | 被引量 : 0次 | 上传用户:greenplastic
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 the analysis of the sub-bottom profile gathered from the north part of Okinawa trough in 1994 and 2000, large area of oblique bedding delta depositions and buried-channels were found in the area near the continental break, which provides the new evidence for the existence of large rivers from the mainland of China entering Okinawa trough during the last period of Late Pleistocene.The sub-bottom profile data show that two sets of the strata characterized by large scale and low angle foreset reflection beddings, appearing as delta deposition, were found in the neritic strata of continental break in the west side of the north part of Okinawa Trough. The existence of large scale of foreset oblique bedding is one of the most important symbols indicating the existence of delta. An erosion surface exits between the two layers of the delta depositions. In the profile these delta sand bodies can reach more than 10 km in length and 30~70 m in thickness. The water depth there is 110~200 m at present, being deep in the north and shallow in the south. The width of the buried channel ranges from several kilometers to over 10 km in general. The discovery of such a large scale of estuarine deposit structure in the survey area has a great significance. Delta deposition lies in two areas. The one in the south is small with the area of 7500km2 and the one in the north is bigger with the area of tens of thousand square kilometers. The main part of the delta body lies in the side of continental shelf near break, with forepart acrossing the break and reaching the upper part of the continental slope.Several of buried channel sections with obvious characteristics of incision and filling reflection configuration were discovered in the area to the west of and in the paleo-deltas distribution area, which reaches more than 10km wide in the profiles, with the incision depth up to 20m. Most of these channels lie in the west or northwest of the delta deposition area, forming an integrated river deposition system. This phenomenon proves that the delta sand bodies came from big rivers of China. The filling of the channels happened in the postglacial trangressive epoch.In the most prosperous period of Wurm Glacial Stage,sea level had descended about 130~150m. Corresponding to the seabed geomorphology here, the fore part of the paleo-delta is just at the location of the ancient coastline. The fore part just lay in the location of the ancient coastline where the depth was about 150m. Buried paleo-delta discussed in this paper was likely formed during that period.According to the dimension of the delta, it can be concluded that the river forming the delta was very big; According to the location, it can be deduced that they were likely the Changjiang River or the Yellow River. On the basis of the analysis of the sub-bottom profile gathered from the north part of Okinawa trough in 1994 and 2000, large area of ​​oblique bedding delta depositions and buried-channels were found in the area near the continental break, which provides the new evidence for the existence of large rivers from the mainland of China entering Okinawa trough during the last period of Late Pleistocene. sub-bottom profile data show that two sets of the strata characterized by large scale and low angle foreset reflection beddings, appearing as delta deposition, were found in the neritic strata of continental break in the west side of the north part of Okinawa Trough. The existence of large scale of foreset oblique bedding is one of the most important symbols indicating the existence of delta. An erosion surface exits between the two layers of the delta depositions. In the profile these delta sand bodies can reach more than 10 km in length and 30 ~ 70 m in thickness. The water depth there is The discovery of such a large scale of estuarine deposit structure in the survey area The one part in the south of the south is small with the area of ​​7500km2 and the one in the north is bigger with the area of ​​tens of thousand square kilometers. The main part of the delta body lies in the side of continental shelf near break, with forepart acrossing the break and reaching the upper part of the continental slope. Sewerral buried channel sections with obvious characteristics of incision and filling reflection configuration were discovered in the area to the west of and in the paleo-deltas distribution area, which reaches more than 10 km wide in the profiles, with the incision depth up to 20 m. Most of these channels lie in the west or northwest of the delta deposition area, forming a n inThe phenomenon proves that the delta sand bodies came from big rivers of China. The filling of the channels happened in the postglacial trangressive epoch. the most prosperous period of Wurm Glacial Stage, sea level had descended about 130 ~ 150m Corresponding to the seabed geomorphology here, the fore part of the paleo-delta is just at the location of the ancient coastline. The fore part just lay in the location of the ancient coastline where the depth was about 150m. in this paper was likely formed during that period .According to the dimension of the delta, According to the dimension of the delta, it can be concluded that the river forming the delta was very big; According to the location, it can be deduced that they were likely the the Yangtze River or the Yellow River.
其他文献
日本有一个叫桑原鹭藏(1870-1931)的,大正十二年(1923年)写了一篇8000多字的文章发表在大阪的报纸上,题目是《中国的宦官》。他说:“独我国自隋唐以来广泛采用中国的制度文物
引言rn截至2016年12月,我国网民规模达7.31亿,其中使用手机上网的人群规模达到6.95亿(占比95.1%).在大学校园中,智能手机的普及率更达到了100%.在大学校园里,微信、共享单车
期刊
In-situ observation on the self designed thermal spraying metal coating for long time protection to the jackets of Center No. 2 platform in the Shengli Oil Fiel
期刊
20世纪下半叶是人类进行自然探索最为活跃的一段时期.新发现、新技术和新概念层出不穷,大大拓展了人们对宇宙和生命的视野和认识.在海洋学领域,深海热液喷口化能自养(chemoli
期刊
From September 1992 to September 1995, the corrosion behavior of three marine steels was studied in Chengdao offshore area by means of individually and electro-
期刊
培养小学生学习英语的兴趣,既是小学阶段英语教学的主要目标,又是提高小学英语水平的重要手段。游戏活动应用于教学中无疑是一种比较切实可行的办法,对游戏在英语在教学中的
紫菜作为一种大型红藻,是目前世界上人工栽培经济价值最高的一种栽培海藻。全世界人工栽培海藻的总产值近3×10~9美元,其中紫菜的产值近2×10~9美元,约占2/3(费修绠等,1998)
期刊
Low concentration chromate conversion technology was successively applied on hot dip Zn-Al alloy coating. The primary dissolution of the active Zn-rich phase wi
期刊
在教育改革进行的过程中,小学体育的教学也正在发生着变革。紧跟时代要求,小学体育在小学生身体素质训练和健康知识教学方面有了更高的要求。体育教学在课堂的内容和形式上都有
海洋碳循环是全球变化研究中的重要领域,它不仅在很大程度上决定了全球气温乃至全球气候的变化趋势,而且还是海洋生态系持续发展的基础,它决定着了海洋生态环境变化的走向.
期刊