Imperial College London
Portrait Picture

Professor Gary Hampson

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Sedimentary Geology
 
 
 
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Contact

 

+44 (0)20 7594 6475g.j.hampson Website

 
 
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Location

 

1.42Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Hampson:2017:10.2110/jsr.2017.55,
author = {Hampson, GJ and Premwichein, K},
doi = {10.2110/jsr.2017.55},
journal = {Journal of Sedimentary Research},
pages = {951--966},
title = {Sedimentologic character of ancient muddy subaqueous-deltaic clinoforms: Down Cliff Clay Member, Bridport Sand Formation, Wessex Basin, UK},
url = {http://dx.doi.org/10.2110/jsr.2017.55},
volume = {87},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Muddy subaqueous clinoforms are a common feature of many modern deltas, particularly those developed in basins with strong waves, tides, or oceanographic currents. Ancient examples have only rarely been reported, implying that they are under-recognized. Herein, the sedimentological characteristics of muddy subaqueous-deltaic clinoforms from the Lower Jurassic Down Cliff Clay Member of the Bridport Sand Formation, Wessex Basin, UK, are described and interpreted, as a reference to re-evaluate other ancient shallow-marine mudstone successions.Deposits below the Down Cliff Clay clinoforms consist of erosionally based, bioclastic sandy limestone beds intercalated with upward-thickening fossiliferous claystones and siltstones (facies association A), which record upward-increasing water depth under conditions of minor input of clastic sediment and reworking by storm waves. These deposits are downlapped by foreset-to-toeset deposits of the subaqueous-deltaic clinoforms, which comprise claystones and siltstones that contain calcareous nodules and are variably bioturbated by a low-diversity trace-fossil assemblages dominated by Chondrites (facies association B). These foreset-to-toeset deposits record slow deposition (undecompacted sediment accumulation rate of c. 4.4 m/Myr) from suspension fall-out and distal sediment gravity flows under conditions of intermittent and/or poor oxygenation of bottom waters. Clinoform foreset deposits dip paleoseaward at 2°, and consist of siltstones and sandy siltstones that are moderately to completely bioturbated by a high-diversity trace-fossil assemblage (facies association C). Thin (< 1 cm), erosionally based, parallel-laminated and current-ripple cross-laminated siltstone and very fine-grained sandstone beds in the foreset deposits record episodic sediment gravity flows and tractional currents. Foreset deposits record relatively rapid deposition (undecompacted sediment accumulation rate of c. 194 m/Myr) above effective storm wave
AU  - Hampson,GJ
AU  - Premwichein,K
DO  - 10.2110/jsr.2017.55
EP  - 966
PY  - 2017///
SN  - 1527-1404
SP  - 951
TI  - Sedimentologic character of ancient muddy subaqueous-deltaic clinoforms: Down Cliff Clay Member, Bridport Sand Formation, Wessex Basin, UK
T2  - Journal of Sedimentary Research
UR  - http://dx.doi.org/10.2110/jsr.2017.55
UR  - http://hdl.handle.net/10044/1/50364
VL  - 87
ER  -
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