Imperial College London
Alternate

Emeritus ProfessorHowardJohnson

Faculty of Engineering, Department of Earth Science & Engineering

Emeritus Professor of Reservoir Geology
 
 
 
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Contact

 

+44 (0)20 7594 6450h.d.johnson

 
 
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Location

 

3.48Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Jackson:2009:10.1016/j.sedgeo.2009.04.008,
author = {Jackson, CA-L and Johnson, HD},
doi = {10.1016/j.sedgeo.2009.04.008},
journal = {Sedimentary Geology},
pages = {77--96},
title = {Sustained turbidity currents and their interaction with debrite-related topography; Labuan Island, offshore NW Borneo, Malaysia},
url = {http://dx.doi.org/10.1016/j.sedgeo.2009.04.008},
volume = {219},
year = {2009}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The Temburong Fm (Early Miocene), Labuan Island, offshore NW Borneo, was deposited in a lower-slope to proximal basin-floor setting, and provides an opportunity to study the deposits of sustained turbidity currents and their interaction with debrite-related slope topography. Two main gravity-flow facies are identified; (i) slump-derived debris-flow deposits (debrites) - characterised by ungraded silty mudstones in 1.5 to >60 m thick beds which are rich in large (>5 m) lithic clasts; and (ii) turbidity current deposits (turbidites) - characterised by medium-grained sandstone in beds up to 2 m thick, which contain structureless (Ta) intervals alternating with planar-parallel (Tb) and current-ripple (Tc) laminated intervals. Laterally discontinuous, cobble-mantled scours are also locally developed within turbidite beds. Based on these characteristics, these sandstones are interpreted as having been deposited from sustained turbidity currents. Cobble-mantled scours indicate periods of intense turbidity current waxing. The sustained turbidity currents are interpreted to have been derived from retrogressive collapse of sand-rich mouth bars (breaching) or directly from river effluent (hyperpycnal flow). Analysis of the stratal architecture of the two facies indicates that routing of the turbidity currents was influenced by topographic relief developed at the top of underlying debrite Turbidite beds are locally eroded at the base of an overlying debrite, possibly due to clast-related substrate ‘ploughing’ during the latter flow event. This study highlights the difficulty in constraining the origin of sustained turbidity currents in ancient sedimentary sequences. In addition, this study documents the importance large debrites may have in generating topography on submarine slopes and influencing routing of subsequent turbidity current and the geometry of their associated deposits.
AU  - Jackson,CA-L
AU  - Johnson,HD
DO  - 10.1016/j.sedgeo.2009.04.008
EP  - 96
PY  - 2009///
SP  - 77
TI  - Sustained turbidity currents and their interaction with debrite-related topography; Labuan Island, offshore NW Borneo, Malaysia
T2  - Sedimentary Geology
UR  - http://dx.doi.org/10.1016/j.sedgeo.2009.04.008
VL  - 219
ER  -
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