Please use this identifier to cite or link to this item: https://hdl.handle.net/1959.11/18471
Title: Thrust-related permeability in the South Wales Coalfield
Contributor(s): Hathaway, Tanya  (author); Gayer, R A (author)
Publication Date: 1996
DOI: 10.1144/gsl.sp.1996.109.01.09
Handle Link: https://hdl.handle.net/1959.11/18471
Abstract: The South Wales Coalfield is a Variscan foreland basin extensively deformed by both linked and isolated thrusts in response to regional NW-SE compressive stress. Thrusts normally strike NE-SW, but transpression has caused a variable dextral rotation of the thrusts to strike E-W and even NW-SE. The range in orientation has allowed thrust-related fractures locally to be opened within the neotectonic stress field in which 0'1 is oriented NW-SE. It is argued that similar thrust-related permeability should be developed in other coal-bearing foreland basins both associated with the Late Carboniferous Variscan/ Appalachian orogeny and with younger compressional tectonic systems. The dominant meso- to major-scale structures formed during the compression of coalbearing sequences are thrusts and folds. Strains at leading and trailing tip-lines of isolated thrusts and in the immediate hanging wall and footwall generate tension cracks which may act as methane conduits. Unsealed, these allow permeability parallel to thrust strike. Decollements form as bed-parallel detachments within coals, developing as pervasive shear zones, characterized by cleavage duplexes and C-S fabrics in which a penetrative new hinterland-dipping fabric is formed. This fabric, under changing regional stress conditions, may be opened to form a highly effective gas migration pathway. Coal-bearing strata develop chevron folds with flexural slip in fold limbs and tension gashes in competent strata, generating porosity and permeability parallel to the strike of fold limbs. Incompetent coal seams are strongly sheared, producing cleavage duplexes with contrasting vergence in opposing limbs.
Publication Type: Book Chapter
Source of Publication: Coalbed Methane and Coal Geology, p. 121-132
Publisher: Geological Society Publishing House
Place of Publication: United Kingdom
ISBN: 189779956X
9781897799567
Field of Research (FOR): 040312 Structural Geology
Socio-Economic Outcome Codes: 970104 Expanding Knowledge in the Earth Sciences
HERDC Category Description: B1 Chapter in a Scholarly Book
Other Links: http://trove.nla.gov.au/version/46590680
Series Name: Geological Society Special Publication
Series Number : 19
Statistics to Oct 2018: Visitors: 61
Views: 63
Downloads: 0
Appears in Collections:Book Chapter

Files in This Item:
3 files
File Description SizeFormat 
Show full item record

SCOPUSTM   
Citations

3
checked on Nov 26, 2018

Page view(s)

86
checked on May 3, 2019
Google Media

Google ScholarTM

Check

Altmetric


Items in Research UNE are protected by copyright, with all rights reserved, unless otherwise indicated.