西太平洋南段新生代构造单元划分、地层特征及其对喜马拉雅造山运动的指示  

Cenozoic tectonic units and their stratigraphic characteristics of southern west Pacific region:Implication for Himalayan orogeny

作　　者：洪文涛 余明刚[2] 杨祝良[2] 邢光福[3] HONG Wentao;YU Minggang;YANG Zhuliang;XING Guangfu(Department of Earth Sciences,Nanjing University,Nanjing 210093,Jiangsu,China;Nanjing Center,China Geological Survey,Nanjing 210016,Jiangsu,China;Wuhan Center,China Geological Survey,Wuhan 430205,Hubei,China)

机构地区：[1]南京大学地球科学与工程学院,江苏南京210093 [2]中国地质调查局南京地质调查中心,江苏南京210016 [3]中国地质调查局武汉地质调查中心,湖北武汉430205

出　　处：《地质通报》2020年第6期839-860,共22页Geological Bulletin of China

基　　金：国家自然科学基金项目《磷灰石地球化学特征对酸性火山喷发及浅部岩浆房过程的指示:以福建永泰云山破火山为例》(批准号:41702061);中国地质调查局项目《中国大地构造演化和国际亚洲大地构造图编制》(编号:DD20190361);《全国陆域及海区地质图件更新与共享》(编号:DD20190373);《地质调查综合智能编图系统与应用》(编号:DD20190415)《国家地质数据库建设与整合》(编号:DD20160351、DD20179384)。

摘　　要：系统梳理西太平洋南段(包括华南、日本、菲律宾及东印度尼西亚)部分地区的新生代构造-地层特征,并以区域性角度不整合为主要依据,对喜马拉雅运动期次、时代及其构造背景进行探讨。研究区受白垩纪末期晚燕山运动的影响,古新统乃至下始新统大都缺失,新生界高角度不整合于前新生界之上。根据不同构造单元内地层沉积-火山类型及接触关系对比,研究区新生界可分为3个构造层,即始新统—渐新统、中新统或上渐新统—中新统及上新统以上。上述3个构造层之间为2个穿时的区域性角度不整合分隔,分别对应早喜马拉雅造山运动(33~20 Ma)及晚喜马拉雅造山运动(5.3~2.6 Ma)界面,并以前者最强烈。区域2次构造运动均与岛弧或裂离微地块向欧亚板块边缘的碰撞拼贴有关,指示西太平洋南段喜马拉雅运动是发生于大陆边缘的增生造山过程,受控于太平洋板块和印度洋-澳大利亚板块运动方向与速率变化。在2次构造事件期间,始新世和中新世弧后的强烈伸展,导致华南大陆边缘古老山系的夷平及边缘海的产生,并最终形成现今的地质及地理格局。In this paper,based on the study of tectono-stratigraphic characteristics of some representative tectonic units of southern Western Pacific region which include South China,Southwest Japan,Philippines,and East Indonesia,the authors present a review of the age,periods and background of Himalayan orogeny.Within the study region,after the late Yanshanian orogeny,most of regions were uplifted with the absence of Paleocene to lower Eocene strata.Cenozoic strata generally cover the pre-Cenozoic basement in angular unconformity form.According to stratigraphic and volcano-sedimentary characteristics of different tectonic units,they can be divided into three structural layers,i.e.,Eocene or Eocene-Lower Oligocene(E 2 or E 2-E 31),Miocene or Upper Oligocene-lowest Miocene(N 1/E 3-N 11)and Pliocene till now(N 2-Q).The above three structural layers are in contact with two regional angular unconformities,and correspond to the early Himalayan orogeny(E 3-N 11,33~20 Ma)and the late Himalayan orogeny(N 2,5.3~2.6 Ma),respectively,with he former being most intense.In different regions,both orogenic movements were usually related to the collision of arcs or detached micro-terranes towards the edge of the Eurasian plate.Obviously,Himalayan orogeny was accretionary orogenesis rather than collision between two continents,and was controlled by changes in the direction and rate of movement of the Pacific and Indian Ocean-Australian plates.Between the episodic tectonic events,it was an intensive extensional setting,which led to the flattening of the palaeocathysian mountain system and the opening of the marginal seas.

关 键 词：新生代 喜马拉雅运动 东南亚 日本 西太平洋 

分 类 号：P534.6[天文地球—古生物学与地层学] P542[天文地球—地质学]