CAJ | 학술논문

假玄武玻璃是一种呈暗色的微晶-隐晶质岩石,一般产于古地震断层滑动面,被认为是研究地震活动的"化石岩". 经过碎裂岩化或摩擦熔融,假玄武玻璃发育于从地表到岩石圈地幔的整个地震活动区,其年代学研究对于揭示某一地区古地震活动频次及发生规律有重要意义.假玄武玻璃的定年一般采用Rb-Sr、~(40)Ar-~(39)Ar、裂变径迹等三种方法,但Sr的扩散性质、假玄武玻璃内部结构和成分的不均一性及其形成高温快速过程中锆石的退火行为等诸多因素,制约了以上三种方法的应用.文中总结了三种方法,分析了其适用范围和局限性,探讨了假玄武玻璃定年研究中最适用的方法和需注意的事项.最后,阐述了假玄武玻璃研究的地震学指示意义.
가현무파리시일충정암색적미정-은정질암석,일반산우고지진단층활동면,피인위시연구지진활동적"화석암". 경과쇄렬암화혹마찰용융,가현무파리발육우종지표도암석권지만적정개지진활동구,기년대학연구대우게시모일지구고지진활동빈차급발생규률유중요의의.가현무파리적정년일반채용Rb-Sr、~(40)Ar-~(39)Ar、렬변경적등삼충방법,단Sr적확산성질、가현무파리내부결구화성분적불균일성급기형성고온쾌속과정중고석적퇴화행위등제다인소,제약료이상삼충방법적응용.문중총결료삼충방법,분석료기괄용범위화국한성,탐토료가현무파리정년연구중최괄용적방법화수주의적사항.최후,천술료가현무파리연구적지진학지시의의.
Pseudotachylyte is an ultimate product of shearing in fault zones and formed with microlite-cryptocrystalline textures. It normally originates in the dislocation surface of ancient earthquakes and is treated as the "fossil rocks" in the paleo-seismic reasearch. Through comminution or friction melting, pseudotachylyte develops from the crustal surface to lithospheric mantle where earthquakes happen. Comprehensive chronological study on pseudotachylytes has great significances on our understanding of the frequency and rules of paleo-seismic events in certain areas. Currently, Rb-Sr, ~(40)Ar/~(39)Ar and fission track are the three methods often used on dating peseudotachylytes. However, many factors have limited their application in the pseudotachylytes' chronological study, such as the diffusion of Sr, the heterogeneities of peseudotachylytes in matrix structure and chemical composition, and the thermal annealing of zircon during the fast megathermal process of its formation, etc. This article summarizes and illustrates these three methods, analyzes their application range and limitations, proposes the proper method and relevant instructions on peseudotachylytes' chrolological study. By the end, this paper elaborates the significances of the pseudotachylyte research to seismology.