五大连池钾质火山岩中的壳源捕虏体特征及地质意义

The Character and Geological Meaning of Captive Rock of the Lithosphere in the Wudalianchi Potassic Volcanic Rocks

黑龙江省五大连池钾质火山岩石中普遍含有壳源捕虏体和捕虏晶,并多赋存于火山集块、浮岩砾、火山渣等各级火山碎屑物及盾状台地的表皮相到内部相火山熔岩中。花岗岩质捕虏体一般大小为5～50cm,捕虏晶一般为0.2～5mm,成分以二长花岗岩为主,少见花岗闪长岩及黑云母英云闪长岩和少量砂岩捕虏体。石英、斜长石、少数钾长石捕虏晶见于各期火山碎屑(物)和熔岩中,其中以石英捕虏晶最为常见。壳源捕虏体中的代表性矿物及浅色玻璃电子探针分析结果表明,火山岩SiO2偏高是岩浆上涌喷发过程中捕获了大量壳源物质的结果。五大连池火山群富钾火山岩岩石化学、地球化学长期保持均一,说明其岩浆直接来自EMⅠ型钾质地幔,岩浆在上升过程中遭受了地壳物质的明显混染。

There are a lot of the captive rocks and crystals of the Lithosphere in the Wudalianchi potassic volcanic rocks,and it is general found in the Loaheishan volcanic prick.The captive rock and crystal of the Lithosphere is kept in the volcanic fragments such as conglomerate,gravel of pumice,scoria,and the shield mesa volcanic rocks from coat to the inside.The size is 5-50 cm of the captive rock of granite,and 0.2-5mm of the captive crystal.The composition is adamellite,a few is the granodiorite,and it is found in the volcanic vent of the Loaheishan.The captive of biotite-tonalite is found in the volcanic rocks of the Wohushan.A few of the sandstone is found in the volcanic vent of the Huoshaoshan and laoheishan.The quartz,plagioclase,and a few K-feldspar are found in the volcanic fragments and the rocks of every state.The quarts are frequently found.The high of SiO2 for the volcanic rocks is the result to capture a lot of the captive rock of the Lithosphere when the magma was ascended,and it is indicated just as from the result of the electric probe to the captive of Lithosphere such as the representative minerals and tint glass.It is the explain the magma was came from the EM Ⅰ type potassic magma,and accept the mix of the lithosphere material distinctness,to keep equal of the petochemistry and geochemistry for a long time of the Wudalianchi potassic volcanic rocks.