CAJ | 학술논문

冲击变质作用是变质作用的一种新类型，是指由陨石或彗星高速降落所产生的高压冲击波，瞬间经过或穿过靶岩所引起的岩石及矿物中的所有变化，击变岩是冲击变质作用的典型产物。近年来国外在这一领域发展很快，但国内尚无详细的研究成果报道。近期在太湖西缘发现了这类击变角砾岩。根据国外研究总结提出的诊断性特征和有效的岩相学研究方法，本文对击变角砾岩中面型微裂隙(PFs)、面型微页理(PDFs)、击变矿物玻璃(diaplectic glass)、击变高温矿物玻璃及熔体(焦石英lechatelierite)及岩石相的转变(岩石熔融)等标志性特征的研究，确证了太湖西缘这类击变岩的存在。研究对推动国内击变岩的研究和发展将起到积极促进作用，并为“太湖冲击事件”增添新的证据。
충격변질작용시변질작용적일충신류형，시지유운석혹혜성고속강락소산생적고압충격파，순간경과혹천과파암소인기적암석급광물중적소유변화，격변암시충격변질작용적전형산물。근년래국외재저일영역발전흔쾌，단국내상무상세적연구성과보도。근기재태호서연발현료저류격변각력암。근거국외연구총결제출적진단성특정화유효적암상학연구방법，본문대격변각력암중면형미렬극(PFs)、면형미혈리(PDFs)、격변광물파리(diaplectic glass)、격변고온광물파리급용체(초석영lechatelierite)급암석상적전변(암석용융)등표지성특정적연구，학증료태호서연저류격변암적존재。연구대추동국내격변암적연구화발전장기도적겁촉진작용，병위“태호충격사건”증첨신적증거。
Impact metamorphism is a new type of metamorphism.It refers to all changes in rocks caused by high-speed impact of meteorite or comet,during which high-pressure shockwaves passed by or penetrated through these target rocks.Impactite is a typical product of impact metamorphism.Research of this field has developed rapidly in some countries,yet no detailed research result was reported in China.In recent years the present authors found some impact breccias in the western margin of Taihu Lake.Petrographic features of these impact breccias are studied based on the identification criteria summarized from previous research experience,together with effective petrographic research methods.Some distinguishing characteristics,e.g.planar fissures(PFs),planar deformation features(PDFs),diaplectic glass,impact-induced high-temperature glasses and melts (lechatelierite),and the phase change of rocks (melting)are recognized,which confirm the existence of impactite in western Taihu area.The present study not only provides new evidence for the existence of the “Taihu Lake impact event”,but also actively promotes the further impactite research in China.