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Potassium-argon dates for major igneous rock types in the Bingham mining district, Utah, range from 39 to 32 m.y. and suggest that:(1) Plutonism, volcanism, and hydrothermal activity were sequential stages in a magmatic history of about 7 m.y. duration.(2) Latitic volcanic rocks, in part, postdate emplacement of the Last Chance...

This paper presents data on the distribution of minor elements in ore and gangue minerals and in adjacent host rock from the Illinois-Kentucky fluorite district and Upper Mississippi Valley zinc-lead district. Comparisons are made of the minor-element abundances between districts and within the paragenetic sequence in individual districts.The ore of...

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Both megafossils and fossil Foraminifera have been obtained from unconsolidated sediments of the Wicomico Formation, which underlies the Penholoway terrace, a coastal feature that formed when the shoreline of the Atlantic Ocean stood about 70 feet higher than at present. Some of the fossils are Tertiary species and are assumed to have been derived from rocks...

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Metallic sulfides, fluorite, barite, and celestite are widespread in the sedimentary rocks of the central United States. Many occurrences are epigenetic concentrations either in known major mineral districts or in clusters of deposits that warrant further exploration for potential ore. Evaluation of trace-element composition, of fluid inclusions, of depositional temperature, and of isotopic composition of sulfur may help discriminate potentially economic deposits from even more...

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A ground-water flow system in southwestern Minnesota illustrates water movement between geologic units and between the land surface and the subsurface. The flow patterns indicate numerous zones of ground-water recharge and discharge controlled by topography, varying thicknesses of geologic units, variation in permeabilities, and the configuration of the basement rock...

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"Colloform" ores have generally been considered to have been deposited as colloidal sulfide gels, and even transported as colloidal "sols." However, studies of doubly polished plates of "colloform" sphalerite-wurtzite assemblages from various deposits reveal crystal growth features that cannot have been formed by crystallization from gels, and indicate that most, and perhaps all, grew directly as minute...

Although the Pine Point ore is relatively poor in useable fluid inclusions, some sphalerite crystals from replacements, vugs, and from " colloform" crusts were found to contain primary or pseudosecondary liquid-gas inclusions adequate for study. Most (132 of 133) of these had low freezing temperatures, indicating exceedingly saline brines. The 112 inclusions suitable for filling-temperature determination homogenized at +51° to...

This report was prepared as a part of the study of the water resources of Clinton, Eaton and Ingham Counties being made for the Tri-County Planning Commission by the Water Resources Division of the U. S. Geological Survey. The report describes one phase of the investigation, that is, the projections...

A possible glacial boulder of undeformed and unmetamorphosed siltstone containing Middle Pennsylvanian plant fossils was recovered from the Bronx. The rock cannot be explained by known geologic relations and suggests the possibility of undetected outliers of Pennsylvanian rocks in the Hudson valley....

The granodioritic Rader Creek pluton of the composite Boulder batholith contains microperthitic alkali feldspar of bulk composition Or65 to Or86 with a structurally variable potassic phase. Complete cell parameters, 2V measurements, and bulk composition are given for 11 feldspar samples. The 131 and 131 reflections for these and 58 additional samples show...

A sensitive resettable odometer reading to 0.01 mile facilitated censusing breeding male redwinged blackbirds (Agelaius phoeniceus) from a vehicle. Territorial males along roadsides were 'marked' with recorded mileage readings rather than with landmarks of the types employed by Hewitt for censuses based on the Lincoln index principle. Sensitive odometers that...

Volcanic glass in marine sediments off Oregon and Washington correlates with continental deposits of Mount Mazama ash by stratigraphic position, refractive index, and radiocarbon dating. Ash deposited in the abyssal regions by turbidity currents is used for tracing of the dispersal routes of postglacial sediments and for evaluation of marine...

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Cracks were observed forming at the surface of Makaopuhi lava lake during the March 1965 Kilauea eruption, and were studied by repeated mapping and observations of this lake; the 1963 Alae lava lake was similarly studied. Cracks open within a minute after molten lava is exposed at the surface, and form either random or oriented orthogonal networks which outline...

Sixteen new chemical analyses of the later rocks of Haleakala Volcano, on the island of Maui, Hawaii, add to the differentiation picture for that volcano. The early rocks of the volcano are tholeiitic. These are followed by dominant hawaiites with less abundant alkalic olivine basalts, picrite-basalts of ankaramite type, and a few mugearites. Still later rocks, separated from...

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Measurements of the rates of population increase, reproduction, and mortality together with an observed age ratio, were used to analyze the population of the Herring Gull in New England. Data from sporadic censuses prior to this study, aerial censuses by the authors, and National Audubon Society Christmas Bird Count indicated...

Many cores raised from the Drake Passage are characterized by alternating zones of foraminiferal ooze and sandysilt. Cores raised from the East Pacific Rise are foraminiferal ooze or alternating siliceous and carbonate ooze. The uranium and thorium concentrations and isotopic ratios in foraminifers separated from these cores were measured by...

Water well drillers gather information essential to recovery tests as part of normal procedure. Added effort could yield additional valuable information. More care in measurement of water levels both before and after a period of pumping can be used with ground‐water formulae to determine approximate well efficiency. A relationship exists between the ability of...