关于铜陵、繁昌地区印支运动的讨论  

A DISCUSSION ON THE INDOSINIAN MOVEMENT IN THE TONGLING AND FANGCHANG AREAS

作　　者：周育才[1] 陈玉屾 

机构地区：[1]安徽省地矿局321地质队

出　　处：《安徽地质》1992年第3期71-78,共8页Geology of Anhui

摘　　要：作者根据1:5万区调资料,提出铜陵、繁昌地区的印支运动（旋回）,存在着三个构造幕:金子运动、南象运动及二者之间的一次构造变动;这三次构造变动均具有褶皱性质。整个印支运动是扬子板块与华北板块逐渐对接的过程,也是区域挤压应力逐渐增强的过程。东马鞍山组之上,黄马青组之下的一套砾岩层"石壁山组"（T₃S）具良好的成层性,系一套沉积底砾岩。砾岩含丰富的孢粉化石组合,证明其形成于晚三叠世卡尼期～诺利克期。砾岩层层位稳定,但不连续,厚度变化大,在印支期向斜核部每每出现;与下伏东马鞍山组、南陵湖组为区域性角度不整合接触;与上覆黄马青组（T₃h）也呈角度不整合;而象山群(J_1-2xn则以高角度不整合覆盖于黄马青组或更老层位之上。不同构造层在形变上也存在着较大的差异性。由砾岩层（Tss）构成的褶皱,开阔平缓;而前东马鞍山期地层则构成紧闭褶皱,两者的翼间角相差60°～70°,显然是两套不同特征的构造层。正确认识印支运动的演化过程及运动性质,对阐述本区的构造演化、沉积作用、岩浆活动及总结矿产分布规律具有重要意义。The author, based on 1:50,000 scale regional survey data, puts forward three tectonic episodes, such as the Jingzi Movement, Nanxiang Movement and a tectonic alternation between the two, within the Indosinian cycle of the Tongling and Fangchang areas, all of which were related to folding activity. And the whole Indosinian Movement was a reflection of the process that the Yangtze Plate was gradually fitting in with the North China Plate and regional compression stress normally in- creasing. A suite of well-layered conglimerate called the Shibishan Formation (T_3s) was recognized as depo- sitional basal conglomerate between the Dongmaanshan Formation and Huangmaqing Formation. Rich sporo-pollen associations in it indicates its formation time ranging from the Carnian Stage to Noric Stage of the late Triassic. The conglomerate often occurs in the cores of the Indosinian synclines, with stable but intermittent horizon. It shows large variation in thickness and its angular unconformity con- tact with the underlying Dongmaanshan Formation and Nanlinghu Formation, and in the same with the overlying Huangmaqing Formation (T_3s). Furthermore, the Xiangshan Group (J_(1-2)xn) is in high angle unconformity overlapping the Huangmaqing Formation or older horizons. Large difference exists in the deformation of various tectonic strata. The fold composed of con- glomerate is wile and flat, while the Dongmaanshanianstrata form a tight fold whose angle between the two flanks is 60°-70°less than the former one. This reflects two types of tectonic strata with different characteristics. Good knowledge of the evolution process and nature of the Indosinian Movement is significant to the interpretation of the tectonic evolution, sedimentation, magmatism and the distribution of mineral resources.

关 键 词：印支运动 金子运动 南象运动 

分 类 号：P5[天文地球—地质学]