Geology topics

Richard L. Konizeski

Publications and source records attributed to Richard L. Konizeski.

3 recordsLinked to original sources

USGS1972

Geology and water resources of the Bitterroot Valley, southwestern Montana, with a section on chemical quality of water

The Bitterroot Valley is a Late Cretaceous structural basin that was partly filled at its deepest point by more than 1,640 feet of Tertiary sediments. These sediments grade valleyward from coarse colluvial deposits along the edges of the valley to fine-grained deposits and then to coarse channel deposits of the ancestral Bitterroot River near the center of the valley. Beneath the flood plain and low terraces of the present Bitterroot River, about 40 feet of Quaternary alluvium overlies the Tertiary sediments. Each spring and summer, at rates greatly exceeding discharge, water infiltrates to the ground-water reservoir in the Tertiary and Quaternary rocks. During the fall and winter, water is released from storage. Net recharge in the spring of 1958 and 1959 was about 90,000 and 82,000 acre-feet, relatively. Net discharge during the rest of each year was about 90,000 and 76,000 acre-feet, respectively. Some surface water available for recharge during high runoff each rejected. During the 1958 and 1959 water years, total surface-water inflow about 1.7 million and 2.0 million acre-feet, respectively. Consumptive use during these water years was about 450,000 and' 400,000 acre-feet, respectively. Move pumping from the ground-water reservoir would provide additional storage space for peak runoff and would increase the potential consumptive use in the valley. Additional wells, capable of yielding more than 250 gpm (gallons per minute), can be constructed on the flood plain of the Bitterroot River and on some of the adjacent low terraces, especially those east of the river. Near Corvallis, on a low terrace, wells capable of yielding 1,000 gpm or more can be constructed. Wells capable of yielding 50 to 250 gpm can be constructed on many of the alluvial fans of the tributary streams. In the remaining area, wells will generally yield only enough water for domestic and stock use. From the hydrologic standpoint, the best use of ground water for irrigation is conjunctive use with surface water. Surface water is adequate early in the season and can be distributed throughout the area. As shortages occur, ground water can be used in areas where it is available in sufficient quantity, allowing the surface water to be used in areas of shortage where ground water is not available. Water in the Bitterroot Valley is of satisfactory chemical quality for domestic, stock, municipal, and most industrial uses. Surface water is softer, as a rule, and contains less dissolved solids than the ground water. Streams heading in the Sapphire Mountains are more mineralized than those heading in the Bitterroot Mountains. Bitterroot River water in October 1955 was about twice as mineralized at Florence, near the outlet of the valley, as it was at Darby, near the inlet, but the difference is not significant in relation to .the usefulness of the water.

Montana↗

USGS1968

Geology and ground-water resources of the Deer Lodge Valley, Montana

The Deer Lodge Valley is a basin trending north-south within Powell, Deer Lodge, and Silver Bow Counties in west-central Montana, near the center of the Northern Rocky Mountains physiographic province. It trends northward between a group of relatively low, rounded mountains to the east and the higher, more rugged Flint Creek Range to the west. The Clark Fork and its tributaries drain the valley in a northerly direction. The climate is semiarid and is characterized by long cold winters and short cool summers. Agriculture and ore refining are the principal industries. Both are dependent on large amounts of water. The principal topographic features are a broad lowland, the Clark Fork flood plain, bordered by low fringing terraces that are in turn bordered by broad, high terraces, which slope gently upward to the mountains. The high terraces have been mostly obscured in the south end of the valley by erosion and by recent deposition of great coalescent fans radiating outward frown the mouths of various tributary canyons. The mountains east of the Deer Lodge Valley are formed mostly of Cretaceous sedimentary and volcanic rocks and a great core of Upper Cretaceous to lower Tertiary granitic rocks; those west of the valley are formed of Precambrian to Cretaceous sedimentary rocks and a core of lower Tertiary granitic rocks. Field relationships, gravimetric data, and seismic data indicate that the valley is a deep graben, which formed in early Tertiary time after emplacement of the Boulder and Philipsburg batholiths. During the Tertiary Period the valley was partly filled to a maximum depth of more than 5,500 feet with erosional detritus that came from the surrounding mountains and was interbedded with minor amounts of volcanic ejecta. This material accumulated in a great variety of local environments. Consequently the resultant deposits are of extremely variable lithology in lateral and vertical sequence. The deposits grade from unconsolidated to well-cemented and from clay to boulder-sized aggregates. Throughout most of the area the strata dip gently towards the valley axis, but along the western margins of the valley they dip steeply into the mountains. In late Pliocene or early Pleistocene the Tertiary strata were eroded to a nearly regular valley divide surface. In the western part of the valley the erosion surface was thinly mantled by glacial debris from the Flint Creek Range. Still later, probably during several interglacial intervals, the Clark Fork and its tributaries entrenched themselves in the Tertiary strata to an average depth of about 150 feet. The resultant erosional features were further modified by Wisconsin to Recent glaciofluvial deposition. Three east-west cross .sections and a corrected gravity map were drawn for the valley. They indicate a maximum depth of fill of more than 5,500 feet in the southern part. Depths decrease to the north to approximately 2,300 feet near the town of Deer Lodge. The principal source of ground water in the Deer Lodge Valley is the upper few hundred feet of unconsolidated valley fill. Most of the wells tapping these deposits range in depth from a few feet to 250 feet. Water levels range from somewhat above land surface (in flowing wells) to about 150 feet below. Yields of the wells range from a few gallons per minute to 1,000 gallons per minute. Generally, wells having the highest yields are on the flood plain of the Clark Fork or the coalescent fans of Warm Springs and Mill Creeks. Discharge of ground water by seepage into streams, by evapotranspiration, and by pumping from wells causes a gradual lowering of the water table. Each spring and early summer, seepage of water from irrigation and streams and infiltration of water from snowmelt and precipitation replenish the ground-water reservoir. Seasonal fluctuation of the water table generally is less than 10 feet. The small yearly water table fluctuation indicates that recharge about balances discharge from th

Water Supply Paper↗

USGS1961

Paleoecology of an early oligocene biota from Douglass Creek Basin, Montana

Douglass Creek basin lies west of the Continental Divide in the northern part of the Rocky Mountain physiographic province. Numerous minor environmental differences exist between the Douglass Creek area and the Pipestone Springs and Canyon Ferry areas east of the Divide. In the 19th century, however, the three areas had identical mammalian species representation, although not equally dense populations. Fossils of an early Oligocene biota have been collected from the Douglass Creek basin . Presence of all but one of the Douglass Creek mammalian species in the Pipestone Springs-Canyon Ferry early Oligocene fauna suggests that the three ancient ecosystems resembled each other in much the same way as the 19th century systems. The early Oligocene deposits and biota of the Douglass Creek basin indicate a moist, temperate climate with seasonal variations. Sediment size and distribution suggest that the cross-valley relief was no greater than it is now. The fish and invertebrate faunas show that a shallow, hard-water lake existed in the area. The flora included a lowland, lake-border association and an upland coniferous forest. Although the ancient Douglass Creek biota doubtless included many species not represented in the fossil collections, most of the mammalian species are probably represented in the combined Douglass Creek , Pipestone Springs, and Canyon Ferry fossil assemblages. If so, the number of mammalian species was about the same as in the 19th century ecosystem.

Montana↗