Mining Publication: Methods of Determining the Orientations of Bedrock Fracture Systems in Southwestern Pennsylvania and Northern West Virginia
Original creation date: January 1977
This Bureau of Mines report describes photo-lineaments obtained from stereoscopic examination of vertical aerial photographs and by the ronchi grating study of aerial photoindex sheets. The photo- lineaments are compared with the trends of oriented fracture systems procured by measuring the compass direction of joints in bedrock. The relative reliability of the methods is shown, and the results are presented in graphical, tabular, and written form. Analyses of field measurements of strikes of bedrock joints in the project area indicate for the most part two intersecting sets of major joints oriented n 76 deg w = n 15 deg e, and n 57 deg w = n 27 deg e. The analyses of lineaments determined by stereoscopic examination of aerial photographs show dominant trends of lineament zones of weakness to be an average of n 65 deg w = n 20 deg e. Analysis of lineaments found by ronchi grid viewing of aerial photoindex sheets indicate dominant trends of n 70 deg w = n 27 deg e. The three methods give similar findings and verify the work of previous authors. The ronchi grid method is a useful guide, but it cannot be substituted for the two more painstaking methods.
Authors: BM Bench, WP Diamond, CM McCulloch
Report of Investigations - January 1977
NIOSHTIC2 Number: 10007787
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, RI 8217, 1977 Jan; :1-35
See Also
- Elastic and Shear Moduli of Coal Measure Rocks Derived from Basic Well Logs Using Fractal Statistics and Radial Basis Functions
- Geologic Factors Causing Roof Instability and Methane Emission Problems: The Lower Kittanning Coalbed, Cambria County, Pa
- Geologic Factors Influencing the Gas Content of Coalbeds in Southwestern Pennsylvania
- Pillar Mechanics of Coal Mine Bursts: A Control Strategy
- Reservoir Rock Properties of Coal Measure Strata of the Lower Monongahela Group, Greene County (Southwestern Pennsylvania), from Methane Control and Production Perspectives
- Roof Support
- Rotary Drilling Techniques Used in the Beckley Coalbed
- Selected Geologic Factors Affecting Mining of the Pittsburgh Coalbed
- Shear Mechanism for Mining-Induced Fractures Applied to Rock Mechanics of Coal Mines
- Spatial Trends in Rock Strength - Can They Be Determined From Coreholes?
- Content source: National Institute for Occupational Safety and Health, Mining Program