ISSN:
1573-0581
Schlagwort(e):
Bengal Shelf
;
seismic stratigraphy
;
Parasound
;
Late Quaternary
;
subaqueous delta
;
lowstand delta
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Geologie und Paläontologie
,
Physik
Notizen:
Abstract An ultra-high-resolution seismic study of the eastern Bengal Shelf with the parametric narrow-beam echosounder Parasound allows the interpretation of late Quaternary depositional patterns in terms of seismic stratigraphy. Accommodation space was still present on the outer shelf during the last lowstand, where a prograding delta developed in the western survey area. Oolitic beach ridges were later formed on top of this lowstand delta. Farther east, large parts of the shelf were exposed to subaerial erosion and a river system extended seaward across the area. A subaqueous highstand delta prograded southwards following the maximum transgression about 7,000 years ago. Its foreset beds exhibit acoustic voids very likely generated by sediment liquefaction, possibly caused by episodic energetic events such as major cyclones and/or earthquakes. Bottomset sediments extend seaward close to the shelf break in the west, whereas no Holocene sediments cover the outer shelf in the east.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1004375908399
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