Origin and Spacing of Cleats in Coal Beds

[+] Author and Article Information
F. T. C. Ting

Department of Geology and Geography, West Virginia University, Morgantown, W.Va.

J. Pressure Vessel Technol 99(4), 624-626 (Nov 01, 1977) (3 pages) doi:10.1115/1.3454584 History: Received June 07, 1977; Online October 25, 2010


Cleats are natural fractures in coal beds resulting from dehydration, devolatilization, and stresses in the earth’s upper crust during coalification. The orientation of these fractures usually parallels that of the fractures (joints) in the associated rocks except that the former is better developed. Spacing of cleats ranges from less than one millimeter to over one meter. The frequency of cleating in coal beds affects not only mining but also the flow of gases in the coal, and the strength of pillars used for roof support. The variation in spacing in controlled primarily by two parameters, namely rank and petrographic composition of the coal. The cleat frequency increases with increasing rank and reaches a maximum at the low-volatile bituminous coal rank. Within the same coal bed at the same mine face, dull coal layers tend to have fewer cleats than bright coal layers. The nature of the cleats is further complicated by local disturbances such as faults, folds, and fissility of bedding planes in the coal seams.

Copyright © 1977 by ASME
Your Session has timed out. Please sign back in to continue.





Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In