大地构造与成矿学
大地構造與成礦學
대지구조여성광학
GETECTONICA ET METALLOGENIA
2010年
1期
20-31
,共12页
徐政语%姚根顺%郭庆新%陈子炓%董庸%王鹏万%马立桥
徐政語%姚根順%郭慶新%陳子炓%董庸%王鵬萬%馬立橋
서정어%요근순%곽경신%진자료%동용%왕붕만%마립교
黔南坳陷%构造变形%成因解析
黔南坳陷%構造變形%成因解析
검남요함%구조변형%성인해석
southern Guizhou depression%structural transfiguration%genetic interpretation%structural pattern
黔南坳陷构造线主体呈NNE至近SN向展布,与坳陷南部NW向-近EW向罗甸断坳以及北部NEE向黔中隆起构造线走向不一,具有明显的构造变形调节特征.经结合地震、MT以及区域地质资料分析,黔南坳陷发育有浅变质与结晶双层结构基底,深部结晶基底表现出明显的"岛链"状结构特征,可能是扬子古陆的外缘增生部分;坳陷总体经历了南华-志留纪、泥盆纪-早三叠世、中三叠世-侏罗纪三期成盆与新元古代早期末、志留纪、中三叠世以来三期隆升,发育了从被动大陆边缘、到前陆、到改造三种盆地类型.今构造格局与变形样式实为多期构造变形形迹的复合、联合与叠加.总体上,坳陷今表层面貌呈现为隔槽式褶皱、是典型的山前逆冲推覆构造发育区发育的侏罗山式构造样式,纵向上可划分为震旦系-下古生界(下)、上古生界(中)及中新生界(上)三个构造层,其中下构造层以发育基底卷入的冲断变形构造为主,中构造层以发育与断层相关的冲起变形构造为主,上构造层以发育滑动褶皱与断展褶皱为主;坳陷今表层构造多受其深层"岛链"状结晶基底结构所控制.
黔南坳陷構造線主體呈NNE至近SN嚮展佈,與坳陷南部NW嚮-近EW嚮囉甸斷坳以及北部NEE嚮黔中隆起構造線走嚮不一,具有明顯的構造變形調節特徵.經結閤地震、MT以及區域地質資料分析,黔南坳陷髮育有淺變質與結晶雙層結構基底,深部結晶基底錶現齣明顯的"島鏈"狀結構特徵,可能是颺子古陸的外緣增生部分;坳陷總體經歷瞭南華-誌留紀、泥盆紀-早三疊世、中三疊世-侏囉紀三期成盆與新元古代早期末、誌留紀、中三疊世以來三期隆升,髮育瞭從被動大陸邊緣、到前陸、到改造三種盆地類型.今構造格跼與變形樣式實為多期構造變形形跡的複閤、聯閤與疊加.總體上,坳陷今錶層麵貌呈現為隔槽式褶皺、是典型的山前逆遲推覆構造髮育區髮育的侏囉山式構造樣式,縱嚮上可劃分為震旦繫-下古生界(下)、上古生界(中)及中新生界(上)三箇構造層,其中下構造層以髮育基底捲入的遲斷變形構造為主,中構造層以髮育與斷層相關的遲起變形構造為主,上構造層以髮育滑動褶皺與斷展褶皺為主;坳陷今錶層構造多受其深層"島鏈"狀結晶基底結構所控製.
검남요함구조선주체정NNE지근SN향전포,여요함남부NW향-근EW향라전단요이급북부NEE향검중륭기구조선주향불일,구유명현적구조변형조절특정.경결합지진、MT이급구역지질자료분석,검남요함발육유천변질여결정쌍층결구기저,심부결정기저표현출명현적"도련"상결구특정,가능시양자고륙적외연증생부분;요함총체경력료남화-지류기、니분기-조삼첩세、중삼첩세-주라기삼기성분여신원고대조기말、지류기、중삼첩세이래삼기륭승,발육료종피동대륙변연、도전륙、도개조삼충분지류형.금구조격국여변형양식실위다기구조변형형적적복합、연합여첩가.총체상,요함금표층면모정현위격조식습추、시전형적산전역충추복구조발육구발육적주라산식구조양식,종향상가화분위진단계-하고생계(하)、상고생계(중)급중신생계(상)삼개구조층,기중하구조층이발육기저권입적충단변형구조위주,중구조층이발육여단층상관적충기변형구조위주,상구조층이발육활동습추여단전습추위주;요함금표층구조다수기심층"도련"상결정기저결구소공제.
The southern Guizhou depression is located in the southwestern margin of the Xuefengshan uplift, its structural outline spreads from NNE to SN, it has the accommodate trait. Based on seismology, MT (telluric electromagnetic sounding ) and geologic survey, the study shows there are different strikes towards the southern Luodian rift-depress and northern Middle Guizhou uplift, and there is a two-layer epimetamorphosed and deep-seated crystallized basement in the southern Guizhou depression. The deep-seated layer represents obviously a structural character of an island chain, which is exterior hyperplasia of the Yangtze ancient landmass. The depression has gone through three periods for basin formation (Neoproterozoic Nanhua Period and Silurian, Devonian-Early Triassic, Middle Triassic-Jurassic) and three periods for basin and orogen transforming (Early Neoproterozoic, Silurian, Middle Triassic). There are four types of basins from the active marginal basin to passive marginal basin, foreland basin, reformation basin in the southern Guizhou depression, and the modern structural pattern and mode are actually resulted from compound, association and superposition of multistage tectonic deformations. As a whole, the depression morphology represents an inter-groove drape, exhibits a Jurassic mountain structural pattern of a thrust nappe, which can be divided into three structural layers(lower structural layer of the Sinian-lower Paleozoic, middle structural layer of upper Paleozoic and upper structural layer of the Mesozoic-Cenozoic). The lower structural layer mostly develops a thrusting-breakup structural pattern of layer-immixture. The middle structural layer mostly develops a crush-up structural pattern of spread-correlation. The upper structural layer mainly yields surge folds, fault-propagation folds and pop-up structures. Generally, the surface structural system of the southern Guizhou depression is controlled by the deep crystallized basement of the island chain.