浙东南鲤溪花岗质杂岩体特征及其成因类型探讨

FEATURES OF LIXI GRANITIC COMPLEX BODY AND ITS GENETIC TYPE DISCUSSION IN SOUNTH-EASTERN ZHEJIANG

鲤溪花岗质杂岩体（下称鲤溪杂岩体）从外至内由微细粒碱长花岗岩、细粒晶洞钾长花岗岩、中粒晶洞钾长花岗岩组成，它们之间为脉动侵入接触关系，可作为一个同源岩浆演化序列建立。本文着重从地质学、岩类学、岩石化学、地球化学等方面论述其特征，探讨其成因类型及所代表的构造环境并涉及其成因机制。结果表明：该杂岩体形成于白垩世早期，是浅成的硅饱和偏碱性碱性花岗岩类；其矿物成分和化学成分基本上为反序演化，属A型花岗岩；其成因机制为双峰式，揭示了浙东南地区在中生代时期处于引张性的构造环境。

Lixi granitic complex body (hereinafter caled as Lixi complex body) is consisted of micro fine -grain alkali feldpar granite, microfine-grain miarolitic potassium feldspar granite and intermediate-grain miarolitic potassium feldspar granite from external part to inner part, which are pulsation -intrusive contact between themselves and can be regarded as cognate magma evolution series. Based on geology, petrography, petrochemlstry and geochemistry etc. of this granitic complex body, the author has dealt with its features and discussed its genetic type, structure enviroment and genetic mechanism. It is shows that this granitic complex body, which belong to super gene silicon-saturated and deviated alkali-alkali granitic types, was formed during early period of cretaceous, and mineral components and chemical compositions of this complex body which can be regarded as A - type granite are essentially reverse - order evolution series, and its genetic mechanism is bimodal type. All of these hinted that south-eastern region of Zhejiang was lay in extensible structure environments during Mesozic eaa peried.