摘要
位于龙门山中段的“彭灌杂岩”推覆体，主要由中晚元古代的二长花岗岩、英云间长岩、钾长花岗岩、辉长岩等组成，用颗粒锆石法测其年龄值为６９９—８５９Ｍａ。该推覆体的推覆面（映秀断裂）为脆－韧性变形，且以脆性变形为主的逆冲推覆断裂，并且有走滑性质。推覆体内部早期为韧性变形，叠加晚期脆性改造，其断裂呈叠瓦状排列，中后部以韧脆性变形为主，至前部脆性变形增强，总体为一个由众多岩片叠置而成的韧脆性冲断推覆体。
Pengguan complex as a nappe in the middle Longmen Mountains consists mainly of adamellite, tonalite, moyite and gabbro in the Middle-Late Proterozoic, with an isotopic age of 699-859 Ma by zircon, decollement fault (Yingxiu fault) is a brittle-ductile fault or a strike-slip reverse thrust predominated by brittle deformation. The nappe underwent ductile deformation on which brittle deformation superimposed, with imbricated faults. The rear and middle are characterized by ductile-brittle deformation and the front is characterized by strong brittle deformation. In general, it is a ductile-brittlely deformed imbricated thrust nappe.
出处
《四川地质学报》
1996年第2期110-114,共5页
Acta Geologica Sichuan
关键词
彭灌杂岩
推覆体
构造变形
Pengguan complex, nappe, tectonic deformation
