THE ACTIVITIES OF MANTLE HEAT SOURCE AND LANDMASS DRIFT IN THE SOUTH CHINA AREA
-
摘要: 在华南及相邻地区广泛出现有各种级别的环形构造,它们是中生代以来深部地幔热源对上部岩石圈,特别是对上地壳塑性基底作用而形成的一种构造型式。通过对环形构造及其有关的岩浆岩的分布规律及形成时间的研究,可以了解中生代时期地幔热源的活动情况,这对于研究华南陆块的构造发育、岩浆活动,陆块漂移都是很有意义的。Abstract: Ring structures of various grades spread widely in the South China area.It is an important intra-plate structure type resulted from the action of mantle heat source on lithosphere since Mesozoic.The second grade ring appeared as four NW-trend ring-chains.The formation time was successively later and later,as moving toward SE.The author tries to explain this phenomena by landmass drift on a fixed heat source settled in mantle.The idea is set up according to the relative movement of mantle heat source (thermal plume) towards SE as the lithosphere (landmass) drifts oppositely above it.It is inferred that South China Landmass drifted a distance of about 600km towards NW during middle-late stage of Mesozoic (190-90 m.y.B.C.) with a speed of 6 km per m.y.Based on the comprehensive analysis of paleomagnetism,paleontology,paleoclimate and track of the mantle heat source,it is indicated that South China Landmass have drifted toward NW in period of Ceno-Mesozic.At Late Permian period (240 m.y.B.C.),it was located in the vicinity Of equator,in the present ocean area between New Guinea and Garoling Islands of SW Pacific.In Late Mesozoic (about 110 m.y.B.C),South China Landmass drifted northwestwards to 14?-24皀orth latitude of the present Philippine Sea Basin.During 190-25 m.y.B.C.,the diift speeded up gradually,varying from 0.6 to 3.8 cm/yr.
-
[1] 张用夏,华南地区环形构造及其成因,地质论评,第30卷第五期,1984年. [2] 全国同位素地质年龄数据编辑组,全国同位素年龄数据汇编(第三集),地质出版社,1983年. [3] M.W.McElhinny,et al.,1981,Fragmentaion of Asia in the Permian,Nature,Vol.293,No.17,p.212-216. [4] 张用夏,亚洲古地磁与大陆拼合,海洋地质与第四纪地质,第3卷第四期,1983年. [5] Morgan,W.,1972,Deep Mantle Convection Plumes and Plate Motions,AAPG.,Vo1.57,p.203-213. [6] A.G.Smith,et al.,1977,Mesozoic and Cenozoic Paleocontinental Maps,Cambridge Univesity Press. [7] 王鸿祯、刘本培,地史学教程,地质出版社,1980年. [8] 李华梅、叶素娟,湖北宜昌与湖南红层的古地磁研究,构造地质问题,科学出版社,1965年. [9] 李晋等,用古地磁方法对元谋人化石年代的初步研究,中国科学,第6期,科学出版社,1976年. [10] 徐世浙,古地磁学概论,地震出版社,1982年. [11] 唐·塔林等,大陆漂移浅说,科学出版社,1978年. [12] 马丽芳,亚洲前寒武系及其构造特征,国际交流地质学术论文集(一),地质出版社,1980年.
点击查看大图
计量
- 文章访问数: 1142
- HTML全文浏览量: 28
- PDF下载量: 307
- 被引次数: 0