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USGS1953

A preliminary report of geochemical investigations in the Blackbird District

This paper reviews an experimental geochemical prospecting survey in the Blackbird cobalt-copper mining district. The district is in east-central Idaho, about 20 miles west-southwest of Salmon. The area is one of deeply weathered nearly flat-topped upland surfaces cut by steep-walled valleys which are tributary to the canyon of Panther Creek. Most of the area has a relatively heavy vegetative cover, and outcrops are scarce except on the sides of the steeper valleys* Because of the importance of the surficial deposits and soils and the physiographic history of the region on the interpretation of the geochemical data, a separate chapter on this subject by Gerald H. Richmond follows the following brief description of the geology of the district.

Idaho↗
USGS1954

Progress report on studies of salt-water encroachment on Long Island, New York, 1953

Nearly all the water used on Long Island, N. Y., is derived by wells from the thick and extensive water-bearing formations that underlie and compose the entire island. The unconsolidated deposits, consisting of sand, gravel, and clay, range in thickness from a few feet in northern Queens County to more than 2,000 feet in southern Suffolk County. Four main and relatively distinct aquifers, all interconnected hydraulically to a greater or lesser degree, have been recognized and delineated at least in a general way. They are, from younger to older, the upper Pleistocene deposits, in which the ground water is mainly unconfined, and three formations in which the water is generally confined - the Jameco gravel, of Pleistocene age, and the Magothy (?) formation and the Lloyd sand member of the Rartian formation, both of Lake Cretaceous age. Except for some artificial recharge, these aquifers are replenished entirely by infiltration of precipitation. Under natural conditions, the fresh water moves into and through the formations, discharging into the sea. With the growth of population on Long Island and the continuously increasing use of water over the years, not only has the infiltration of precipitation been seriously impeded at places, but the withdrawals from the ground-water reservoir have increased markedly. These factors have upset the natural balance between the fresh surface and ground water of the island and the surrounding sea water, and with increased use of water will do so more and more, thus leading to salt-water encroachment. In a sense, the whole problem of utilization of ground water on Long Island is one of determining how much ground water can be withdrawn without serious salt-water encroachment.

New York↗