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| Titel |
Structure and climate controls on the evolution of a Mid-Late Jurassic alluvial fan-delta system in the western part of Yanshan fold-and-thrust belt |
| VerfasserIn |
Chengfa Lin, Shaofeng Liu, Xiang Yao, Pengfei Ma |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250126336
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| Publikation (Nr.) |
 EGU/EGU2016-6044.pdf |
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| Zusammenfassung |
| The Yanshan fold-thrust belt experienced several significant tectonic events during Mesozoic
time and developed thrust fault-bounded intramontane sedimentary basins. However,
elaborate works of sedimentology is inadequate in the Yanshan belt, particularly in its
western segment, leading to a failure in comprehensively understanding how bounding-faults
and climate change influence the basin filling processes. Our detailed sedimentological study
of the Middle Jurassic Xiahuayuan Formation and Upper Jurassic-Lower Cretaceous
Jiulongshan Formation in the Xiahuayuan basin of northern Hebei province, indicates a
genetic relationship between the evolution of an alluvial fan-delta system and the tectonic and
climate setting. The Xiahuayuan Formation was assigned to a debris flow-dominated
Gilbert-type fan-delta composed of topset conglomerates, foreset massive siltstone-fine
grained sandstone interbedded with lenticular conglomerate units and bottomset/lake bottom
fine-grained deposits, spatially restricted to the northern part of the basin. While the lower
Jiulongshan Formation was considered as a relatively small debris flow- and turbidity
currents-dominated fan-delta with a single-ramp portrait, prograding into the middle part of
the basin. And the upper part of Jiulongshan Formation contributed to the lake bottom
component of the delta system during the forming of the Jiulongshan Formation.
Our results reveal a transformation of a fan-delta from Gilbert-type to single-ramp
type and the basinward migration of this fan-delta during Mid-Late Jurassic in the
Xiahuayuan basin. And it is assumed that the activity of a thrust fault along the northern
basin margin and the rapid switch of climate conditions from warm and humid to
hot and dry triggered the transformation and migration of this fan-delta system. |
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