福建地质
福建地質
복건지질
GEOLOGY OF FUJIAN
2011年
3期
189-199
,共11页
构造带%变质变形%期次划分%时代厘定%长乐-南澳
構造帶%變質變形%期次劃分%時代釐定%長樂-南澳
구조대%변질변형%기차화분%시대전정%장악-남오
Tectonic zone%Deformation and Metamorphic%divide stages%stipulation of the age%Changle-Nan＇ao
长乐-南澳构造带中发育有晚侏罗世早期、晚侏罗世晚期及早白垩世等3个不同时期的变质变形侵入岩。不同期次侵入岩具有不同的变质变形特征。根据糜棱岩的空间分布、糜棱叶理的切割关系等，表明构造带在中生代发生了3期韧性剪切变形及相关的动力变质作用。第一期为（北西西－南东东向）右行－推覆韧性剪切，具低角闪岩相变质、深部构造层次长石相塑性变形等特征；第二期为（北北西－南南东向）左行－逆冲韧性剪切，具高绿片岩相变质、中深层次长石－石英相塑性变形的特征；第三期为具正断层性质的右行走滑韧－脆性剪切（主剪切面倾向反转为倾向南东），具低绿片岩相变质、中－浅层次石英相韧－脆性变形特征。根据对具有不同变质变形特征的3期侵入岩进行的同位素测年研究所获得7个（组）锫石微区（LA—ICPMS）U－Pb同位素年龄数据，结合地质接触关系等，将3期变质变形时代分别厘定为晚侏罗世早期（149．2Ma～145．4Ma）、晚侏罗世晚期（145．4～137Ma）及早白垩世晚期（100Ma±）。
長樂-南澳構造帶中髮育有晚侏囉世早期、晚侏囉世晚期及早白堊世等3箇不同時期的變質變形侵入巖。不同期次侵入巖具有不同的變質變形特徵。根據糜稜巖的空間分佈、糜稜葉理的切割關繫等，錶明構造帶在中生代髮生瞭3期韌性剪切變形及相關的動力變質作用。第一期為（北西西－南東東嚮）右行－推覆韌性剪切，具低角閃巖相變質、深部構造層次長石相塑性變形等特徵；第二期為（北北西－南南東嚮）左行－逆遲韌性剪切，具高綠片巖相變質、中深層次長石－石英相塑性變形的特徵；第三期為具正斷層性質的右行走滑韌－脆性剪切（主剪切麵傾嚮反轉為傾嚮南東），具低綠片巖相變質、中－淺層次石英相韌－脆性變形特徵。根據對具有不同變質變形特徵的3期侵入巖進行的同位素測年研究所穫得7箇（組）锫石微區（LA—ICPMS）U－Pb同位素年齡數據，結閤地質接觸關繫等，將3期變質變形時代分彆釐定為晚侏囉世早期（149．2Ma～145．4Ma）、晚侏囉世晚期（145．4～137Ma）及早白堊世晚期（100Ma±）。
장악-남오구조대중발육유만주라세조기、만주라세만기급조백성세등3개불동시기적변질변형침입암。불동기차침입암구유불동적변질변형특정。근거미릉암적공간분포、미릉협리적절할관계등，표명구조대재중생대발생료3기인성전절변형급상관적동력변질작용。제일기위（북서서－남동동향）우행－추복인성전절，구저각섬암상변질、심부구조층차장석상소성변형등특정；제이기위（북북서－남남동향）좌행－역충인성전절，구고록편암상변질、중심층차장석－석영상소성변형적특정；제삼기위구정단층성질적우행주활인－취성전절（주전절면경향반전위경향남동），구저록편암상변질、중－천층차석영상인－취성변형특정。근거대구유불동변질변형특정적3기침입암진행적동위소측년연구소획득7개（조）부석미구（LA—ICPMS）U－Pb동위소년령수거，결합지질접촉관계등，장3기변질변형시대분별전정위만주라세조기（149．2Ma～145．4Ma）、만주라세만기（145．4～137Ma）급조백성세만기（100Ma±）。
Metamorphic and deformed granitic rocks in Changle-Nan＇ao fault zone was dividied into the early Late Jurassic, late Late Jurassic and Early Cretaceous three periods. Different period＇s granitic rocks had different characteristics of deformation and metamorphism. According to metamorphism and deformation style, and the foliation crosscutting relation in different period＇s intrusions, ductile deformation and related dynamic metamorphism in this tectonic zone can he divided into three stages： The first stage＇s ductile shear zone is characterized by deep structural level plastic deformation and low amphibolite facies metamorphism, dextralthrusting from NWW to SEE; the second stage＇s ductile shear zone is characterized by the middle-deep structural level ductile shear deformation and high greenschist facies metamorphism, sinistral-thrusting from NNW to SSE; The third stage＇s ductile-brittle shear zone is characterized by mid-shallow brittle-ductile shear deformation and low greenschist facies metamorphism , normal-dextral strike slip.According to the LA-ICPMS zircon U-Pb isotopic ages and the geologic relations ofthree periods granitic rocks which have different characteristics of deformation and metamorphism, they were proved that the first stage deformation and metamorphism took place at early Late Jurassic （149.2--145.4 Ma）, and second＇s occurred in late Late Jurassic （145.4-- 137 Ma）, third＇s happened in late Early Cretaceous （ca. 100 Ma） .
