地质学基础-地质构造.pptVIP

Chapter4GeologicalStructure

第四章地质构造;§2-1geologicaltimeandChronologicalscale

地质年代与地质年代表;1Absolutedatingmethods;Radiometricdatingisnotwithoutdifficultiesbutisbyfarthemostwidespreadmethodappliedtodetermineabsoluteagesbetween100and4500My.

Uranium(铀),Thorium〔钍〕andPotassium〔钾〕arebyfarthemostcommonradiogenicisotopesintheEarthscrust.Radiocarbonisimportantindatingorganicremainsfromtherelativelyrecentpast.;2relativedatingmethods;?Theprincipleofsuperpositionstatesthatolderbedsarecoveredbyyoungerbeds.Inotherword,theyoungestunitisusuallyatthetopinasedimentarysequence.;?Theprincipleoffossilsuccessionstatesthatorganismsevolvethroughtimesothatparticularformscanbeusedasagemarkerswherevertheyarefound.;?Themethodofrocklayerscontactrelationstatesthatthecontactrelationsamongrocklayersisthehistoryrecordsofcrustmovement,magmaactivities.Sogeologicaleventscanbeorderedbytherelationofrocklayers,theseincludes：

;①therelationsamongsedimentaryrock,

〔沉积岩之间的接触关系〕

②therelationsamongtheigneousrock,

〔岩浆岩之间的接触关系〕

③therelationbetweensedimentaryrock

andigneousrock.

〔沉积岩和岩浆岩之间的接触关系〕;①Therelationsamongsedimentaryrock

Therelationsamongsedimentaryrockcanbe

dividedinto：

conformity〔整合〕

Unconformity〔不整合〕.

Theconformitymeansthatstratawasformedinastablesedimentaryenvironment,thedipandstrikeofstrataarebasicallythesame.;conformity〔整合接触关系〕;Unconformity〔不整合〕.;整合接触;②therelationsamongtheigneousrock,

;③therelationbetweensedimentaryrock

andigneousrock.;;二、Chronologicalscale;;;多

么

富

有

想

象

力

的

比

喻

！;§2-2Basicshapeandclassificationof

geologicalstructure

地质构造的根本形态和分类;Structuresmaybeconvenientlysubdividedintotwogroups:

brittlestructures脆性构造

recordingthebrittle-elasticfailure弹脆性破坏

ofrocksin