Seismic architecture of the tidal channel system of Galinhos, equatorial Atlantic, Brazil
Marine Geology(2022)
摘要
This study aims to reconstruct the Holocene evolution of a semiarid tidal channel system in response to the deglacial sea-level rise and modern coastal processes. With a maximum water depth of approximately 10 m, this very shallow system is in the easternmost part of the Brazilian equatorial margin along a tide-dominated coast in a semidiurnal, mesotidal regime. The channel system is interconnected with the Atlantic Ocean through a tidal inlet formed by the Galinhos spit. This work comprised ship and land-based fieldwork with sedimentological and stratigraphic approaches. Four seismic units (U1-U4) and seismic horizons (H1-H4) were identified by reconstructing the stratigraphic architecture. The results show that: (1) the formation of paleochannels in the current spit may have started before the middle Holocene; (2) there was a network of pre-existing channels with a different configuration filled by units U2 and U3, constituting the transgressive and highstand systems tracts; (3) spit migration is the key factor to open and close inlets; (4) internal configuration patterns show a less energy and monotonous depositional environment above H4, within unit U4 (which started at similar to 5000 cal yrs. BP); (5) the current system configuration has been active since the formation of the U3 unit since the closure of the paleochannels; and (6) the Galinhos region shows progressive sedimentary infilling of a lagoon behind a coastal spit via sediment accumulation from marine sources and its ultimate transformation into a coastal swamp with tidal channels.
更多查看译文
关键词
Seismic stratigraphy,Equatorial margin,High-resolution seismic,Sea level,Barrier island,Paleochannels
AI 理解论文
溯源树
样例
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要