MBMG-1845

Montana Bureau of Mines and Geology

Located in Prairie County, Montana, this groundwater monitoring location is associated with a water well in the Lower Tertiary aquifers.

Well Construction

Depth Description
0.0-340.0 ft 4.0 in diameter pvc-sched40 casing
243.0-330.0 ft 4.0 in diameter saw slots screen
Depth Lithology Description
0.0-19.0 ft unknown SAND;YELLOW-SOFT VFG-SILTY-POORLY CONSOLIDATED.
19.0-20.0 ft unknown COAL SOFT
20.0-28.0 ft unknown CLAY; SOFT MED GRAY W/CARBONACEOUS STREAKS- BENT.
28.0-32.0 ft unknown COAL; SOFT
32.0-41.0 ft unknown CLAY; AS ABOVE
41.0-42.0 ft unknown COAL
42.0-46.0 ft unknown CLAY; LT-MED. GRAY AS ABOVE
46.0-59.0 ft unknown CLAY; MED. GRAY- SOFT V SILTY
59.0-60.0 ft unknown COAL
60.0-65.0 ft unknown CLAY; AS ABOVE- BENTONITIC
65.0-68.0 ft unknown COAL; HARD
68.0-70.0 ft unknown CLAY; AS ABOVE
70.0-80.0 ft unknown SAND; LT GRAY- VFG- SILTY- SOFT
80.0-91.0 ft unknown CLAY; MED GRAY- W/CARBONACEOUS STREAKS- BENTONITIC SOFT
91.0-100.0 ft unknown COAL
100.0-133.0 ft unknown SILTSTONE- V HARD
133.0-142.0 ft unknown CLAY; AS ABOVE
142.0-150.0 ft unknown SHALE; GREEN GRAY- V SILTY- FIRM
150.0-156.0 ft unknown SILT; GRAY- P CONSOLIDATED- CLAYEY
156.0-157.0 ft unknown SILTSTONE; V HARD- GRAY-BROWN
157.0-178.0 ft unknown SHALE; LT GRAY- BROWN- PART CARBONACEOUS- PART V BENTONITIC
178.0-182.0 ft unknown COAL; VERY HARD
182.0-199.0 ft unknown SHALE; GRAY-GREEN V SILTY
199.0-203.0 ft unknown SILT; SOFT- V CLAYEY
203.0-210.0 ft unknown SHALE; GRAY-GREEN V SILTY
210.0-213.0 ft unknown COAL
213.0-227.0 ft unknown SILT; LIGHT GRAY- PART V CLAYEY
227.0-228.0 ft unknown SILTSTONE; GREEN- V HARD
228.0-245.0 ft unknown SHALE; GRAY-GREEN GRAY-BROWN PART CARBONACEOUS PART BENTONITIC
245.0-288.0 ft unknown SAND; VERY-FINE-GRAINED AND SILT; GRAY- POORLY CONSOLIDATED
288.0-291.0 ft unknown SHALE; SOFT CARBONACEOUS
291.0-305.0 ft unknown SAND; GRAY- VERY-FINE-GRAINED- VERY SILTY
305.0-340.0 ft unknown SHALE; DARK GRAY- BROWN- CARBONACEOUS- INTERBEDDED WITH THIN SILT BEDS

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