Types and Distribution Characteristics of Slope Breaks of Large-Type Down-Warped Lake Basins
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摘要: 在海相盆地和断陷湖盆中都发育坡折带, 并对层序和沉积起重要控制作用, 这一观点已得到广泛关注并被普遍接受.对准噶尔盆地侏罗系的研究表明, 在大型坳陷湖盆中也发育坡折带, 其成因类型丰富, 可划分为构造坡折、沉积坡折和侵蚀坡折.并且分布广泛, 表现为多级坡折的特点, 在剖面上具有正向阶梯状组合、逆向阶梯状组合、沟谷组合、山梁组合和沟梁组合等组合样式; 在平面上具有梳状组合、帚状组合、斜交组合、喇叭状组合和平行组合等组合样式.于一定构造背景下发育的一组有成因联系并具类似组合样式特征的坡折带可构成一个构造坡折域.在准噶尔盆地侏罗纪湖盆中共划分出6个构造坡折域.坡折带对层序、沉积和非构造圈闭的发育具有十分重要的控制作用, 在不同构造坡折域形成不同的水系和沉积体系特征.Abstract: Slope breaks are developed in both marine and rift lake basins, and their controlling impact on sequence and deposition has already been widely concerned and accepted. However the study in Jurassic Junggar basin shows that slope breaks are also developed in large down-warped lake basins. Their genetic types can be divided into structural slope break, sedimentary slope break and erodent slope break. These breaks are distributed widely, showing mutual grades characteristics. On the profiles, they have forward direction grade combination, downward direction grade combination, ditch-valley combination, mountain combination and ditch-mountain combination. On the planes, they display pectination combination, broom combination, oblique combination, trumpet combination and parallel combination. A set of slope breaks developed in the specific structural settings with genetic correlations and similar combination characteristics consist of a structural slope break domain. The Jurassic lake basin, Junggar, was distinguished into 6 structural slope-break domains. It is evident that slope breaks have an important control on sequence, deposition and the development of tectonic traps and different water systems and different depositional characteristics are formed in different structural slope-break domains.
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Key words:
- slope break /
- structural slope-break domain /
- down-warped lake basin /
- Junggar basin /
- Jurassic
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