Mineral resources of the Diablo Mountain Wilderness Study Area, Lake County, Oregon
No abstract available.
Oregon↗
Geology topics
Research about Lake County, Oregon
Source-linked reports with geographic coverage including Lake County, Oregon.
Interstitial brines in playa sediments
Study of several closed drainages in the Great Basin has shown that the interstitial solutions of shallow, fine-grained playa deposits store a large quantity of dissolved solids and are often more concentrated than associated lakes and ponds, except in peripheral zones of stream or ground-water inflow. These interstitial fluids, when compared with local runoff, impoundments, or spring waters, commonly have a distinctive ionic composition which sometimes cannot be explained by either simple mixing of surface and subsurface inflow or by evaporative concentration. At Abert Lake, Oregon, the interstitial solute concentrations increased with depth to values as much as five times greater than the lake, except where springs indicate significant ground-water input. Where Na + , Cl, and CO 2 species constitute more than 90% of the solutes, Na + Cl − "> Na+Cl− ratios in the lake water are lower than in interstitial solutions of bottom cores and higher than in playa fluids. At the same time, Na + K + "> Na+K+ ratios are highest in the fluids of lake bottom muds and lowest in playa interstitials. In deeper playa profiles, interstitial Na + Cl − "> Na+Cl− tended to decrease with depth (5 ft. maximum). In the Abert Lake area, as in other parts of the western Great Basin, Na + Cl − "> Na+Cl− ratios are indicative of total CO 2 in solution and the effects of organic decay in surficial sediments. These ratios, coupled with data on silica and bulk density, show that higher P CO2 accompanying decay promotes silicate dissolution and hydrogen ion exchange, stripping alkalis from sediment which had preferentially adsorbed K + when entering the lake. On subsequent loss of pore fluid in the playa regime, silica initially released to solution in the lake environment is readsorbed on dissolution products.
Oregon↗
Mineral appraisal of the Poker Jim Ridge and Fort Warner areas of the Hart Mountain National Antelope Refuge, Lake County, Oregon
The Poker Jim Ridge and Fort Warner areas, which are candidate areas for inclusion in the National Wilderness Preservation System, are in the Hart Mountain National Antelope Refuge in east-central Lake County, south-central Oregon. The two areas form part of an upraised and tilted fault block--a structural element that is typical of the northern part of the Great Basin province. Rocks in the two areas are principally volcanic in origin. They have been faulted, uplifted, and tilted eastward, the older rocks having been more strongly deformed than the younger ones.
Oregon↗
Occurrence of ground water near Ana Springs, Summer Lake Basin, Lake County, Oregon
Ana Springs are near the north end of Summer Lake Basin, a closed fault-block basin in Lake County Oregon. The water of the springs rises by artesian pressure from lava-rock aquifers through about 150 feet of overlying thinly bedded lake deposits to discharge at the bottom of an impounding reservoir, the spring orifices being beneath 30 to 36 feet of water. On the valley floor less than a mile south and southwest of the reservoir artesian wells appear to tap the same lava rock from which the waters of the springs arise. Observations of the piesometric surface of the artesian water during flow tests show that three artesian wells, 30/16-1R1, 30/17-7D1, and -7F1, are hydraulically connected with a fourth, 30/16-1R2, and that well 30/16-1R2 is hydraulically connected with Ana Springs. A fifth artesian well, 30/16-12A1, did not show hydraulic connection with the other four wells during the short-term tests made. Mathematical constant derived from the tests permit calculations which indicate that the four wells, 30/16-1R1, -1R2, 30/17-7D1, and -7F1, when flowing at a combined rate of 4,600 gpm for 100 days, may lower the pressure head on Ana Springs by an amount equal to 2.7 feet of water, This lowering in pressure may cause a decrease in the rate of discharge of Ana Springs by about 4.4 cubic feet per second, or about 5 percent of the present wintertime rate of discharge. This diversion (5 percent) would be within the limit of error of single measurement of the the spring discharge. Chemical and temperature characteristics of thew Ana Spring water indicate it is similar to the water of the five lava-rock wells.
Oregon↗