岩石矿物学杂志
巖石礦物學雜誌
암석광물학잡지
ACTA PETROLOGICA ET MINERALOGICA
2009年
5期
433-449
,共17页
花岗岩%岩石成因%海西晚期%黑龙江
花崗巖%巖石成因%海西晚期%黑龍江
화강암%암석성인%해서만기%흑룡강
granite%petrogenesis%Late Hercynian%Heilongjiang
黑龙江宝山地区在构造上位于兴蒙造山带东部的松嫩地块和佳木斯地块之间的伊春-延寿花岗岩带北段,区内分布大面积的古生代-中生代花岗岩.其中海西晚期花岗岩,岩性主要为碱长花岗岩、二长花岗岩和花岗闪长岩等,锆石U-Pb法 LA-ICP MS测年结果为252.6±3 Ma.其主量元素表现出富Si、略富Al、富碱质和低Mg、低Ca的特点;微量元素表现出富集Rb、Nd、K、Pb、U和亏损Nb、Ta、P、Ti等高场强元素的特点,并且Sr、Ba呈明显的负异常;稀土元素具有明显的轻稀土元素富集、重稀土元素相对亏损的特征,轻重稀土元素分馏程度较高.岩石总体上属于高钾钙碱性花岗岩,是岩浆经历了高度结晶分异作用的产物.矿物化学和岩石地球化学特征表明其特征类似于S型花岗岩,源岩物质来自于地壳.
黑龍江寶山地區在構造上位于興矇造山帶東部的鬆嫩地塊和佳木斯地塊之間的伊春-延壽花崗巖帶北段,區內分佈大麵積的古生代-中生代花崗巖.其中海西晚期花崗巖,巖性主要為堿長花崗巖、二長花崗巖和花崗閃長巖等,鋯石U-Pb法 LA-ICP MS測年結果為252.6±3 Ma.其主量元素錶現齣富Si、略富Al、富堿質和低Mg、低Ca的特點;微量元素錶現齣富集Rb、Nd、K、Pb、U和虧損Nb、Ta、P、Ti等高場彊元素的特點,併且Sr、Ba呈明顯的負異常;稀土元素具有明顯的輕稀土元素富集、重稀土元素相對虧損的特徵,輕重稀土元素分餾程度較高.巖石總體上屬于高鉀鈣堿性花崗巖,是巖漿經歷瞭高度結晶分異作用的產物.礦物化學和巖石地毬化學特徵錶明其特徵類似于S型花崗巖,源巖物質來自于地殼.
흑룡강보산지구재구조상위우흥몽조산대동부적송눈지괴화가목사지괴지간적이춘-연수화강암대북단,구내분포대면적적고생대-중생대화강암.기중해서만기화강암,암성주요위감장화강암、이장화강암화화강섬장암등,고석U-Pb법 LA-ICP MS측년결과위252.6±3 Ma.기주량원소표현출부Si、략부Al、부감질화저Mg、저Ca적특점;미량원소표현출부집Rb、Nd、K、Pb、U화우손Nb、Ta、P、Ti등고장강원소적특점,병차Sr、Ba정명현적부이상;희토원소구유명현적경희토원소부집、중희토원소상대우손적특정,경중희토원소분류정도교고.암석총체상속우고갑개감성화강암,시암장경력료고도결정분이작용적산물.광물화학화암석지구화학특정표명기특정유사우S형화강암,원암물질래자우지각.
The Baoshan area in Heilongjiang Province is tectonically located in the north of the Yichun-Yanshou fold belt lying between the Songliao Block and the Jiamusi Block in the east of the Xingmeng oregenic belt. Large volumes of Paleozoic-Mesozoic granitic rocks are distributed in this area. This paper deals emphatically on the Late Hercynian granitoids composed of alkali-feldspar granite, monzogranite and granodiorite. LA-ICP MS (laser inductively coupled plasma mass spectrometry) zircon U-Pb dating yielded an age of 252.6± 3 Ma. Major element analyses show high SiO_2 and alkali content, slightly high Al_2O_3 content and low MgO and CaO content. Trace element studies demonstrate the enrichment of Rb, Nd, K, Pb, U and depletion of HFSE (high field strength elements) such as Nb, Ta, P, Ti. The samples are enriched in LREE (light rare earth elements) and depleted in HREE (heavy rare earth elements), suggesting a high degree of fractionation. The granites generally belong to the high-K calc-alkaline series and might be produced by the magma that experienced a high degree of crystallization differentiation. Mineral chemistry and petrological geochemistry show that the granites are quite similar to S-type granite, with the material source derived from the crust.