Application of borehole geophysics at the Retsof salt-mine collapse site, western New York

Conference · Fri Nov 01 04:00:00 EST 1996

OSTI ID:381515

Williams, J H ^[1]

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1. Geological Survey, Troy, NY (United States)

Borehole-geophysical methods were used in the hydrogeologic characterization of the valley fill and bedrock at the site of the 1994 Retsof salt-mine collapse in western New York. Collapse of the mine roof and fracturing of the overlying bedrock in the southern downdip section of the 10-square-mile salt mine resulted in flow of ground water into the historically dry mine at a rate of more than 15,000 gallons per minute. A suite of borehole- geophysical logs, including caliper, gamma, electromagnetic induction, specific conductance, temperature, acoustic televiewer, video camera, and impeller flowmeter, was collected from 17 test wells. Most of the logged test wells were 700 to 850 feet deep and were completed with steel casing through the valley fill and finished as open hole in the bedrock. The valley-fill sequence at the mine-collapse site was about 500 feet thick and the bedrock sequence, from top of bedrock to the salt mine, was about 600 feet thick. Analysis of the borehole-geophysical logs and correlation with reported drilling logs delineated (1) glaciolacustrine fine-grained sediments that restricted downward flow of surface water and ground water from the overlying alluvium; and (2) ground-water flow zones in glaciofluvial sand and gravel in the mixed deposits of the lower valley fill, near the top of bedrock, and in fracture zones at the limestone-dolomite contact and in the lower part of the dolomite. Fractures that provided the vertical hydraulic connection between the ground-water flow system and the mine were penetrated by several test wells drilled within the collapse. Borehole geophysics proved to be a highly efficient method for obtaining information on the hydrogeology of the valley fill and bedrock at the Retsof salt-mine collapse site. This information was critical in evaluating potential remedial actions at the site and developing a plan of study to assess the effects of the mine collapse on the water resources of the area.

• OSTI ID: 381515
• Report Number(s): CONF-960477--
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
FAILURES
GEOPHYSICAL SURVEYS
MINES
NEW YORK
REMEDIAL ACTION
ROOFS
SALT DEPOSITS
WATER INFLUX