摘要:北美东部被动大陆边缘是世界上最古老的完整被动大陆边缘之一，是研究被动大陆边缘发育演化的天然实验室。本文在大量国外研究成果的基础上，应用盆地构造解析方法，深入研究了北美东部被动大陆边缘盆地群的地质结构和构造演化特征，并揭示了盆地群的油气地质规律。研究认为，北美东部盆地群沉积充填和不整合面发育具有明显的分段性和差异性。以区域不整合面为界，不同段盆地可划分为不同的构造层：南段盆地可划分为两套构造层；中段南部盆地可划分为3套构造层；中段北部盆地可划分为4套构造层；而北段盆地可划分为5套构造层。盆地群整体经历了陆内裂谷—陆间裂谷—被动大陆边缘的演化过程，但不同段盆地的构造演化具有明显的分段性和迁移性：晚三叠世沉降中心位于南段盆地；早侏罗世初期迁移至中段盆地，南段大陆开始裂解；中侏罗世逐渐迁移至北段盆地，中段大陆开始裂解；早白垩世晚期，北段大陆开始裂解。受持续的抬升剥蚀及大西洋岩浆活动省的联合作用，南段盆地和中段大多数盆地缺乏油气保存条件；斯科舍盆地和大浅滩盆地是主要的含油气盆地，以上侏罗统烃源岩为主，主要发育断层—背斜圈闭和盐体刺穿圈闭，整体表现为“自生自储”和“下生上储”的特征。
关键词: 被动大陆边缘/
分段性/
地质结构/
构造演化/
油气聚集/
北美东部
Abstract:The passive continental margin of eastern North America is one of the world's oldest intact passive margins, and is a natural laboratory for studying passive-margin development. Base on a large number of overseas research results, this paper used the basin structural analysis method to deeply study the geological structure and tectonic evolution characteristics of the passive continental margin basins group of eastern North America, and revealed hydrocarbon geology patterns of basins group. It is shown that sedimentary filling and unconformity development of basins group of eastern North American have obvious segmentation and difference. Based on regional unconformities, basins in different segmentations can be divided into different structural layers. Basins in the southern segment can be divided into two tectonic layers, southern basins in the central segment can be divided into three tectonic layers, northern basins in the central segment can be divided into four tectonic layers, and basins in the northern segment can be divided into five tectonic layers. The basins group have undergone the evolution process of intracontinental rift-intercontinental rift-passive continental margin, but the tectonic evolution of basins in different segmentations has obvious segmentation and migration. The subsidence center was located in the southern segment during Late Triassic. It migrated to the central segment in earliest Jurassic, and the continent in the southern segment began to break up. The subsidence center migrated to the northern segment in Middle Jurassic, and the continent in the central segment began to break up. The continent in the northern segment began to break up during late Early Cretaceous. Basins in the southern segment and most basins in the central segment are lack of hydrocarbon preservation conditions due to a combination of sustained uplift and erosion and the CAMP. The Scotian Basin and the Grand Banks Basin are the main petroleum basins, mainly developed the Upper Jurassic source rocks and fault-anticline and salt body piercing traps. Basins are characterized by self generation and self reservoir and lower generation and upper reservoir.
Key words:Passive continental margin/
Segmentation/
Geological structure/
Tectonic evolution/
Hydrocarbon accumulation/
Eastern North America
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