Techniques and tests for measuring joint intensity
Anomalous intense jointing has been cited as a reason for gas production from fractured shales, coal mine roof falls, some construction problems, and increased water-well yields. The Parsons lineament in West Virginia, was chosen to develop and test field and analytical methods for measuring joint intensity. Rocks of the Middle and Upper Devonian Chemung Group and Catskill Formation, and the Mississippian Pocono Formation along the Allegheny Front, were studied to determine how the fracturing effects of the Petersburg lineament varies with depth and with different lithologies. In the Plateau province, rocks of the Lower and Middle Pennsylvanian Pottsville Group and Allegheny Formation were measured to determine the westward extent of the lineaments. A large roadcut in northern West Virginia was chosen to study the effects of a stream channel on coal cleat intensities. Joint spacing was found to be the only necessary measurement, other than strike and dip, to determine joint intensity. Rocks inside the Parsons and Petersburg lineaments were found to be more intensely jointed than rocks adjacent to the lineaments. Along the Allegheny Front, the Petersburg lineament affects rock at least one half mile below ground level. Farther west in the Plateau province, joint intensities measured indicate that the high-intensity joint systems of the Parsons and Petersburg lineaments are disrupted or terminated. Air photograph and LANDSAT lineaments may be an aid in locating structural lineaments or areas of intense jointing, but do not necessarily define or bound such areas.
- Research Organization:
- West Virginia Univ., Morgantown (USA). Dept. of Geology and Geography
- DOE Contract Number:
- AC21-76ET12138
- OSTI ID:
- 6429105
- Report Number(s):
- DOE/ET/12138-1275; ON: DE83009587
- Country of Publication:
- United States
- Language:
- English
Similar Records
Method to identify zones of intense jointing with application to the Parsons Lineament, West Virginia
Bedding-orientation contours of Middle Devonian shales exposed in the Middle Mountain syncline, Valley and Ridge province, West Virginia
Related Subjects
03 NATURAL GAS
FRACTURING
MEASURING METHODS
GEOLOGIC FISSURES
BLACK SHALES
DEPTH
FRACTURES
ROCKS
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHATTANOOGA FORMATION
COMMINUTION
DIMENSIONS
ENERGY SOURCES
FAILURES
FOSSIL FUELS
FUELS
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
MATERIALS
OIL SHALES
580100* - Geology & Hydrology- (-1989)
030200 - Natural Gas- Reserves
Geology
& Exploration