Dynamics of prolonged salt movement in the Glückstadt Graben (NW Germany) driven by tectonic and sedimentary processes

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• 作者：Michael Warsitzka ; Jonas Kley…
• 关键词：Salt tectonics ; Glückstadt Graben ; Extensional basin ; Structural restoration
• 刊名：International Journal of Earth Sciences
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：106
• 期：1
• 页码：131-155
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Geology; Geophysics/Geodesy; Sedimentology; Structural Geology; Mineral Resources; Geochemistry;
• 出版者：Springer Berlin Heidelberg
• ISSN：1437-3262
• 卷排序：106

文摘

The formation of salt structures exerted a major influence on the evolution of subsidence and sedimentation patterns in the Glückstadt Graben, which is part of the Central European Basin System and comprises a post-Permian sediment thickness of up to 11 km. Driven by regional tectonics and differential loading, large salt diapirs, salt walls and salt pillows developed. The resulting salt flow significantly influenced sediment distribution in the peripheral sinks adjacent to the salt structures and overprinted the regional subsidence patterns. In this study, we investigate the geometric and temporal evolution of salt structures and subsidence patterns in the central Glückstadt Graben. Along a key geological cross section, the post-Permian strata were sequentially decompacted and restored in order to reconstruct the subsidence history of minibasins between the salt structures. The structural restoration reveals that subsidence of peripheral sinks and salt structure growth were initiated in Early to Middle Triassic time. From the Late Triassic to the Middle Jurassic, salt movement and salt structure growth never ceased, but were faster during periods of crustal extension. Following a phase from Late Jurassic to the end of the early Late Cretaceous, in which minor salt flow occurred, salt movement was renewed, particularly in the marginal parts of the Glückstadt Graben. Subsidence rates and tectonic subsidence derived from backstripping of 1D profiles reveal that especially the Early Triassic and Middle Keuper times were periods of regional extension. Three specific types of salt structures and adjacent peripheral sinks could be identified: (1) Graben centre salt walls possessing deep secondary peripheral sinks on the sides facing away from the basin centre, (2) platform salt walls, whose main peripheral sinks switched multiple times from one side of the salt wall to the other, and (3) Graben edge pillows, which show only one peripheral sink facing the basin centre.