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Monmouth County includes an area of 538 square miles in east-central New Jersey. The climate is characterized by moderate temperature, moderate humidity, and moderate precipitation. The exposed rocks in the area are chiefly sands and clays, which range in age from Late Cretaceous through Recent. The formations strike northeast-southwest and dip...

No abstract available....

From gravity and limited seismic data obtained in 1957, Pakiser and others (1960) reported a thickness of Cenozoic deposits in the deepest part of Mono Basin, California, of 5.5 ± 1.5 km. Later, in 1962, from a series of chemical explosions in the westernmost part of Mono Basin and outside...

Material of obscure structure that forms part of the hanging wall of the great sodium borate ore body at Kramer, Kern County, Calif., is interpreted herein as collapsed insoluble claystone layers left where interbedded borax has been dissolved. Nodular ulexite in such collapsed material is secondary; relationships between primary borax...

Various physical and chemical processes may be envisioned which will cause anomalous pressures on an underground fluid. In order to consider the maintenance of anomalous pressure, it is necessary to consider the problem as one of nonsteady fluid flow. The time rate of pressure change and maintenance depends upon the...

Physico-chemical mechanisms have been suggested to account for anomalous fluid pressures in the geologic environment which require a fluid source at depth. The persistence of anomalous pressure is a problem that involves nonsteady fluid flow. The hydrodynamics and particular boundary conditions control the time rate of pressure change and its...

The Puerto Rico Trench is parallel to and north of Puerto Rico and the Virgin Islands and reaches depths of more than 8000 meters. Puerto Rico, the closest land area, has a central longitudinal core of Cretaceous and early Tertiary volcanic rocks, some serpentinite of undetermined age, and numerous small...

Right-lateral displacement of 80 to 120 miles across the western Great Basin is indicated by the consistent disruption of sedimentary facies and thickness trends of formations ranging in age from late Precambrian to Mesozoic. Some of this displacement occurs as fault slip and some as a more pervasive large-scale drag...

Ammonoid faunas representative of every major part of Triassic time occur at one place or another in the marine Triassic strata of western and arctic North America. Though some intracontinental provincialism is evident, particularly among Lower and Middle Triassic ammonoid faunas, various local sections where parts of the faunal sequence...

Cenozoic deposits of the Silver Peak region, western Nevada, and adjacent California consist principally of continental sedimentary and pyroclastic rocks of the Esmeralda Formation and lavas and tuffs of the Silver Peak volcanic center.The sedimentary rocks comprise several thick sequences of tuffaceous volcanic sandstone and siltstone and interbedded air-fall tuff....

Oxygen isotope analyses have been obtained for coexisting minerals in several blue-schist-facies metamorphic rocks from California, Oregon, and New Caledonia. Detailed isotopic studies were made on a continuous exposure of schist in Ward Creek, California, previously described by Coleman and Lee (1962). The oxygen isotope fractionations among coexisting minerals in...

Five species of shallow neritic Pleistocene mollusks from a central California marine terrace give these Th230/U238 ages: 88,000; 68,000; 76,000; 16,000; 100,000; 91,000 (from data in Blanchard and others, 1967). With one exception, the ages fall between 68,000 and 100,000 years. This broad grouping of ages, its general agreement with dates...

Paleomagnetic and potassium-argon studies support geologic evidence that the lower member of the Bandelier Tuff was deposited 1.4 m.y. ago. The upper member erupted about 1.0 m.y. ago and was followed by caldera collapse which formed the 12- to 14-mile diameter Valles Caldera. Postcaldera activity which resulted in the eruption...

No abstract available. ...

Resurgent cauldrons are defined as cauldrons (calderas) in which the cauldron block, following subsidence, has been uplifted, usually in the form of a structural dome. Seven of the best known resurgent cauldrons are: Valles, Toba, Creede, San Juan, Silverton, Lake City, and Timber Mountain. Geologic summaries of these and Long...

Several metamorphic and plutonic events have been recognized in the Klamath Mountains utilizing potassium-argon and rubidium-strontium mineral and whole-rock ages. The oldest known metamorphic event in the region produced the Abrams Mica Schist and the co-extensive Salmon Hornblende Schist. Strontium evolution diagrams indicate that the age of primary metamorphism of...

Shatter cones abound in the central uplift of Sierra Madera and they occur as far as 6.5 kilometers from the center. Apical angles average near 90 degrees. Whole cones and full cones represented by diversely oriented cone segments in any structural block show relatively uniform orientations of axes and a...

No abstract available....

Polymineralic sulfide grains, composed principally of Fe sulfide and Fe-Cu sulfide, with magnetite, have been studied mineragraphically and by electron probe, and interpreted in terms of experimental data for the system Fe-Ni-Cu-S. The three main phases are monosulfide solid solution, a Cu-Fe sulfide (solid solution) with composition near cubanite, and...

Photographs of a Late Cretaceous species of Aquilapollenites illustrate the usefulness of the scanning electron microscope (SEM) for the study of fossil pollen. The SEM has the advantages of great depth of focus and wide range of magnification; using present techniques, its use for the study of unsectioned specimens is limited to the observation of surface detail....

Thick salt deposits are present in the Middle Pennsylvanian Paradox Member of the Hermosa Formation in the Paradox Basin of southeast Utah and southwest Colorado. Data suggest that the original thickness of these deposits was from 5000-6000 feet. Locally, however, these deposits have been subjected to intense deformation and flow, resulting in thicknesses as great as 14,000 feet. Each salt bed is part of a series of partial and...

Time residuals from 75-km segments of 18 crustal seismic-refraction profiles in the Basin and Range province are used to investigate the validity of the linear-regression model and to make large sample estimates of the variance in the travel time distributions.A formula for unbiased estimates of velocity uncertainty is derived, assuming a...

In the 3000-square-mile area of southeastern Mississippi and northeastern Washington Parish, Louisiana, which has Tatum dome in its center, rocks of known Jurassic to Recent age are more than 20,000 feet thick. They are underlain by an unknown thickness of Louann Salt of Jurassic (?) age. The age, thickness, and nature of the sedimentary rocks between the salt and the basement, as well as the character...

The isotopic composition of lead in feldspar varies widely from pluton to pluton of the Late Cretaceous Boulder batholith, encompassing the following ranges in isotopic values: 16.9-18.1 for Pb 206/Pb 204; 15.4-15.7 for Pb 207/Pb 204; and 37.7-38.5 for Pb 205/Pb 204. Although each pluton has a characteristic isotopic composition, the fact that Pb 206/Pb 204 for the Butte...