1 引言对裂开的(或被动的)大陆边缘了解的主要障碍是缺少对陆洋过渡带深部构造的知识。尽管人们对陆壳和洋壳地震构造资料掌握日渐增多,但对居于其间的过渡壳的研究仍然是一个新领域。由于被动边缘上常常覆盖着一层厚沉积物,而且构造方面急剧的侧向变化,诸如由较薄的、较年轻的洋壳取代厚的较老的陆壳,故被动边缘对地震调查提出了一项独特的挑战。本文着重介绍北美东部边缘这样一个典型被动边缘的深部构造。该边缘形成于三叠纪-侏罗纪潘基亚泛大陆裂谷活动以及大西洋中脊扩张中心的诞生时期。从广义上说,它由三大 1 Introduction The main obstacle to understanding the rifted (or passive) continental margin is the lack of knowledge of the deep tectonics of the continental transition zone. Although people have more and more masters of the seismic structural data of the continental crust and the oceanic crust, the research on the transitional shell in between is still a new field. Because passive edges are often covered with thick sediments and structurally sharp lateral changes, such as replacing thick, older continental crusts by thinner, younger oceanic crusts, the quasi- A unique challenge. This article focuses on the deep tectonics of a typical passive edge such as the eastern edge of North America. The margin was formed during the Triassic-Jurassic Panchia continental rifting and the birth of the center of the Atlantic Ridge. Broadly speaking, it consists of three major