McCabe, Peter J (1975) The sedimentology and stratigraphy of the Kinderscout grit group (Namurian, R1) between Wharefdale and Longdendale. Doctoral thesis, Keele University.

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Abstract

The thesis is the result of a sedimentological and stratigraphical survey of the Kinderscoutian (Ri)g Namurian, in the Central Pennine Basin between CThrufe dale and Longdendale. Twenty two facies are described and the relationships between them discussed. Three major "assemblages" are distinguished in the 200 to 570m thick, deltaic sequence.
The, lowest assemblage, A, has sandstones interpreted as turbidites and grain flow deposits. Interbedded with the sandstones is mudrock, representing normal deposition from suspension. The, sandstones thicken, become less parallel sided and became more abundant higher in the sequence. Channels, up to 30m deep are common in the upper part of the sequence. Assemblage A is interpreted as the deposits of submarine fans.
Assemblage B is essentially a coarsening upward sequence, with silt dominant in the lower part and very coarse, pebbly sandsone dominant in the upper part, but shows great lateral variation. Units, up to 14m thick, with beds parallel, to inclined bases, dipping at up to 16°, are interpreted as slope gully deposits. Rippled beds, within these units are thought to be due to deposition under density current flow. Channels-over 9m deep, infilled with coarse sandstone are thought to be due to deposition under density current flow. Channels, over 9m deep, infilled with coarse sandstone are thought to. have been out and infilled by immature turbidity, currents. Overbank deposits from such channels are also recognised. Assemblage B is interpreted as the delta slope sediments.
At the base of Assemblage 0 large channels occur infilled with cross-bed sets up to 35m thick. Unlaminated sandstones occur at the base of the channels. Undulatory bedded sandstone, with crest to crest lengths between 9 and 23m and heights of 1m, occur on some channel sides. The large-scale cross-beds are interpreted as channel infill or bedform features; the majority being thought to be transverse bars. The undulatory beds are thought to be spurs formed by corkscrew vortices in the front of the bedforms with skewed crestlines. The unlaminated sandstones are thought to have formed at the reattachment points of the large bedforms. The remainder of the assemblage consists of; cosets of medium-scale cross bedded, coarse sandstones interpreted as fluviatile deposits; coarsening and fining-upward sequences of mudrock, wavy bedded sandstone and müdrock and ripple laminated sandstones, interpreted as interdistributary bay deposits; and seatearths and coals representing terrestrial conditions. The whole assemblage is interpreted as a delta top sequence with the large channels at the base being the main delta distributaries.
The facies analysis is used as the basis of a new lithostratigraphic subdivision of the Kinderscout Grit Group. The following formations are defined:- Mam Tor Sandstone Formation, Shale Grit Formation, Todmorden Sandstone Formation, Otley Sandstone Formation (all of Assemblage A), Grindslow Shale Formation, Hebden Bridge Shale and Sandstone Formation, Sileden Shale and Sandstone Formation (all of Assemblage B) and the Kinderscout Grit Formation (Assemblage C). Facies equivalent formations are diachranous between Wharfedale and Longdendale, commencing earlier towards the north/northeast.
All the palaeocurrent indicators suggest a current toward the south-southwest. The thickness of Assemblage A and B is thought to reflect the depth of the basin. Both are thickest in the south of the area, apparently due to northward shallowing against the underlying Skipton Moor Grits. The thickness of Assemblage C is thought to reflect the amount of subsidence and compaction during deposition of the assemblage. The assemblage is thickest in the north due to the earlier establishment of terrestrial conditions in the north. Subsidence, apparently at even rate throughout the basin, and compaction are thought'to be the major controlling factors of transgressions in Assemblage C.
The whole sequence is interpreted as the deposits of a river dominated delta entering a partially enclosed basin Which was, for most of the time, of low salinity, although occasionally fully marine conditions were established.

Item Type: Thesis (Doctoral)
Subjects: Q Science > QE Geology
Divisions: Faculty of Natural Sciences > School of Geography, Geology and the Environment
Depositing User: Lisa Bailey
Date Deposited: 06 May 2019 15:59
Last Modified: 06 May 2019 15:59
URI: http://eprints.keele.ac.uk/id/eprint/6272

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