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The relation between fresh and salty ground water in southern Nassau and southeastern Queens counties, Long Island, New York

An investigation of the geology and ground - water conditions in a part of southwestern Long Island , including the construction of 8 deep and 5 shallow test and observation wells, has been completed by the Geological Survey in cooperation with the Nassau County Department of Public Works and the New York State Water Power and Control Commission. In this area are four main water -bearing units of Late Cretaceous and Pleistocene age. Ground water having a higher than normal salt content is encountered in some wells that penetrate the upper three units. Although the presence of this water constitutes a potential threat, existing fresh - water supplies apparently are in little immediate danger under present conditions. The " salty " ground water has chloride concentrations ranging from about 40 to 18,000 ppm (parts per million), generally more than about 2,000 ppm. It occurs in several bodies, seaward of and beneath the fresh water in the respective aquifers, and is in contact with the fresh water through zones of diffusion. The largest salt- water body, confined under artesian pressure, is in the Jameco gravel and the Magothy (?) formation beneath extreme southwestern Nassau County and adjoining southeastern Queens County . This body is thought to have occupied a substantial part of its present extent since at least 1895. It probably has been and is now encroaching, very slowly, because of increased pumping from the fresh - water bodies and possibly as a result of a postglacial rise of sea level. The rate of encroachment under present conditions probably is less than 100 feet per year. Application of the Ghyben-Herzberg principle to compute depths to the contact between salty and fresh ground water was found to give erroneous results. More accurate depths and a clearer understanding of the relation between heads in adjoining bodies of fresh and salty ground water are obtained by use of a formula adapted from one given by M. King Hubbert.

New York

Hydrogeology of the West Branch Delaware River basin, Delaware County, New York

In 2009, the U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, began a study of the hydrogeology of the West Branch Delaware River (Cannonsville Reservoir) watershed. There has been recent interest by energy companies in developing the natural gas reserves that are trapped within the Marcellus Shale, which is part of the Hamilton Group of Devonian age that underlies all the West Branch Delaware River Basin. Knowing the extent and thickness of stratified-drift (sand and gravel) aquifers within this basin can help State and Federal regulatory agencies evaluate any effects on these aquifers that gas-well drilling might produce. This report describes the hydrogeology of the 455-square-mile basin in the southwestern Catskill Mountain region of southeastern New York and includes a detailed surficial geologic map of the basin. Analysis of surficial geologic data indicates that the most widespread surficial geologic unit within the basin is till, which is present as deposits of ablation till in major stream valleys and as thick deposits of lodgment till that fill upland basins. Till and colluvium (remobilized till) cover about 89 percent of the West Branch Delaware River Basin, whereas stratified drift (outwash and ice-contact deposits) and alluvium account for 8.9 percent. The Cannonsville Reservoir occupies about 1.9 percent of the basin area. Large areas of outwash and ice-contact deposits occupy the West Branch Delaware River valley along its entire length. These deposits form a stratified-drift aquifer that ranges in thickness from 40 to 50 feet (ft) in the upper West Branch Delaware River valley, from 70 to 140 ft in the middle West Branch Delaware River valley, and from 60 to 70 ft in the lower West Branch Delaware River valley. The gas-bearing Marcellus Shale underlies the entire West Branch Delaware River Basin and ranges in thickness from 600 to 650 ft along the northern divide of the basin to 750 ft thick along the southern divide. The depth to the top of the Marcellus Shale ranges from 3,240 ft along the northern basin divide to 4,150 ft along the southern basin divide. Yields of wells completed in the aquifer are as high as 500 gallons per minute (gal/min). Springs from fractured sandstone bedrock are an important source of domestic and small municipal water supplies in the West Branch Delaware River Basin and elsewhere in Delaware County. The average yield of 178 springs in Delaware County is 8.5 gal/min with a median yield of 3 gal/min. An analysis of two low-flow statistics indicates that groundwater contributions from fractured bedrock compose a significant part of the base flow of the West Branch Delaware River and its tributaries.

New York

Zirconium and hafnium in the southeastern Atlantic States

The principal source of zirconium and hafnium is zircon, though a minor source is baddeleyite, mined only in Brazil. Zircon is an accessory mineral in igneous, metamorphic, and sedimentary rocks, but rarely occurs in hardrock in minable quantities. The principal sources of zircon are therefore alluvial deposits, which are mined in many countries of five continents. The principal commercial deposits in the United States are in Florida, though others exist elsewhere in the southeastern Coastal Plain. The evidence indicates that conditions for the accumulation of workable deposits of heavy minerals were more favorable during the interglacial stages of the Pleistocene epoch than during Recent time. Therefore detrital ores of large volume and high tenor are more likely to be found in the terrace deposits than along the present beaches. Other concentrations of heavy minerals, however, are possible at favored sites close to the Fall Line where the Tuscaloosa formation rests upon the crystalline rocks of the Piedmont province. A score of heavy and semiheavy minerals occur in the detrital deposits of Florida, but the principal salable minerals are ilmenite, leucoxene, rutile, and zircon, though monazite and staurolite are saved at some mining plants. Commercial deposits of heavy minerals are generally required to have a tenor of 4 percent, though ores with a lower tenor can be mined at a profit if the content of monazite is notably high. The percentages of zircon in the concentrates ranges from 10 to 16 percent, and in eastern Florida from 13 to 15 percent. Thus the tenor in zircon of the ore-bearing sands ranges from 0.4 to 0.6 percent. The content of hafnium in zircon is immaterial for many uses, but for some purposes very high or very low tenors in hafnium are required. Alluvial zircon cannot be separated into such varieties, which, if needed, must be obtained from sources in bedrock. It thus becomes necessary to determine the Hf : Zr ratios in zircon from many kinds of bedrock. Granitic rocks are the principal sources of zircon, though not the best sources of zircon with a high tenor in hafnium. A general study by the Geological Survey of the granitic rocks of the Southeastern Atlantic States has been in progress for 10 years, and hundreds of samples of granitic accessory minerals have been acquired. Thirty samples of zircon from these collections were selected for spectrographic and X-ray determinations of their tenors in hafnium. Nine other samples of alluvial zircon were included, of which three are from Florida and six from foreign countries. No domestic zircon was discovered with very high or very low tenors in hafnium. The volume of zircon in the southeastern Coastal Plain is enormous, but most of it is not recoverable. The minable reserves of heavy minerals, however, are very large, and from these it is estimated conservatively that 10 million short tons of zircon can be obtained. The corresponding amounts of zirconium and hafnium, using the mean Hf:Zr ratio of the deposits in Florida, are 4,868,000 and 112,000 tons, respectively. These reserves could be delivered, if needed, at the rate of 100,000 tons a year.

Florida, Georgia, North Carolina, South Carolina,

Methods used to reconstruct historical daily streamflows in northern New Jersey and southeastern New York, water years 1922–2010

A study was conducted by the U.S. Geological Survey, in cooperation with the New Jersey Department of Environmental Protection, to reconstruct streamflows for use in the RiverWare model. Methods and data used to estimate daily reconstructed streamflows at 53 sites in selected subbasins in northern New Jersey and southeastern New York are presented in the report. These subbasins contain one or more surface-water diversions that are operated or have been operated in the past by water purveyors or the New Jersey Department of Environmental Protection. Reconstructed streamflows are estimates of those streamflows that would have occurred without the effects of changes in reservoir storage or surface-water diversions by water purveyors. Reconstructed flows at 47 sites were determined from monthly observed streamflows, changes in reservoir storage, and surface-water diversions. Monthly reconstructed streamflows were calculated directly for those months with sufficient data. Missing monthly reconstructed flows were estimated from relations between selected calculated values of monthly reconstructed flows and monthly observed flows at selected index gages. Daily reconstructed flows were determined from the disaggregation of monthly reconstructed flows on the basis of daily observed flows at selected streamgages. At six sites, reconstructed flows were determined from relations between discrete measurements of observed streamflows and daily observed streamflows at selected index gages.

New Jersey, New York

Permafrost and ground-water conditions in the Glennallen area, Alaska

This report is an outgrowth of permafrost and geologic field studies now in progress in the southeastern Copper River basin, Alaska and is in response to inquiries for information on permafrost and ground-water conditions. Various private and governmental groups have encountered severe differential settlement of building foundations on permafrost, and consequent maintenance problems. Settlement and expansion of communities in the area also have been retarded by the apparent lack of a ready and large source of potable water. The information below is presented to make available data on permafrost and ground-water conditions for the benefit of those undertaking construction projects in the area.

Alaska

Petrographic and trace-element data on rocks from the Yemen Arab Republic

Petrographic descriptions are given for rocks in the Yemen Arab Republic (YAR), including mainly Precambrian igneous and metamorphic rocks from the southeastern part of the country, which previously was geologically undescribed. Also included are descriptions of Cretaceous and/or Tertiary lavas of the Yemen Volcanics, Miocene(?) alkali granite, Pliocene caprock of the Guma salt dome, and late Pleistocene and Holocene basalts of the Aden Volcanic Series (?). The petrographic studies permitted the selection of 11 samples of rock for future use in obtaining isotopic analyses for age determinations. Analyses of these rock specimens for trace amounts of gold, indium, mercury, selenium, and thallium completed the geochemical studies. Results of these analyses are interpreted to show that regional geochemical exploration should be undertaken for base and precious metals near Jibal Hufash, the Manakhah area, the region around Al Bayda, the Sa'dah-Majadh area, and the Wadi Jawf area. Additional studies of trace elements in commercial salt deposits of the YAR should be made to evaluate the amounts of mercury and selenium in this industrial raw material.

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