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A plant fossil assemblage from the roof shale of the No. 25 anthracite bed in Pennsylvania indicates that the upper part of the Llewellyn Formation is much younger than the lower part of the Allegheny Group or Conemaugh Group correlation that was indicated by Read and Mamay (1960). These results confirm the conclusions of Fontaine and White (1880), White (1900), and Darrah (1969) who suggested that the highest coals of the Llewellyn Formation could be equivalent to the Monongahela Group.
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One of the greatest excitements for a petroleum geologist is to venture into the frontier, to explore and drill "where no man has gone before." Over 50 years ago Bill Rex, a Kansas oilman, was tapped to lead the first oil drilling expedition into the Alaskan Arctic. He successfully assembled and outfitted a Naval Seabee expedition whose mission was to drill the first well north of the Arctic Circle, Umiat #1. The story of Umiat #1 is one of anecdotes and personal accounts. This paper relates the successes and tribulations of that Seabee exploration venture, as told to the writer by some of the participants.
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High-resolution seismic, sidescan-sonar, multibeam bathymetry, and sediment sampling techniques were used to map the surficial geology and shallow subbottom stratigraphy of a segment of the inner shelf and nearshore region of New York-New Jersey metropolitan area. Preliminary analyses of these data provide a sedimentologic framework for addressing a wide range of science and management issues. Principal features identified include: 1) a series of sharply defined, rippled scour depressions in the nearshore areas of Long Island and New Jersey that are thought to be an erosional pattern indicative of storm-induced cross-shelf sediment-transport processes from the shoreface; 2) outcropping Upper Cretaceous to early...
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Ground-water samples from four monitoring well networks in the Hudson River basin were analyzed for pesticides (detection limits from 0.001 to 0.018 ??g/L). The most frequent detections were in samples from shallow depths beneath agricultural areas. Concentrations of pesticides in samples from all four networks were generally below 0.10 ??g/L, and the concentration of only one (cyanazine) exceeded any maximum contaminant levels or health advisory levels set by the U.S. Environmental Protection Agency. The well networks represented two land-use and two well-depth categories as follows: 1. agricultural shallow wells - two springs and 14 wells finished less than 15 m below land surface in unconfined unconsolidated...
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We used sidescan-sonar imagery detailing almost 300 km2 of the sea floor in west-central Long Island Sound in conjunction with bathymetry, sediment samples, bottom video, and seismic data to interpret the area's surficial geology. The distribution of sediments and sedimentary environments interpreted from these data sets represents the Quaternary geology, regional bathymetry, and effects of modern tidal- and wave-driven currents. Four distinct sedimentary environments consisting of 1) fine-grained deposition, 2) sorting and reworking, 3) coarse-grained bedload transport, and 4) erosion or nondeposition, were identified and mapped. Relatively low-energy environments prevail where deposition of clayey silts occurs...
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Palynology of Miocene and Pliocene formations in the Delmarva Peninsula of Maryland and Virginia reveals a significant representation of exotic pollen interspersed in pollen assemblages that are otherwise comparable to those from the modern vegetation of the Mid-Alantic coastal plain region. The late Tertiary arboreal pollen (AP) assemblages are dominated by oak, hickory, pine, birch and alder with minor amounts of mid- and southern coastal tree taxa, as well as minor spruce and hemlock and a trace of fir. Nonarboreal pollen (NAP) include grass, sedge, composite and aquatic taxa. Exotic pollen in these assemblages represent plants now foreign to this region. They may be placed in three categories. First, there are...
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New conodont alteration index (CAI) and vitrinite reflectance (%Ro) data collected from drill holes in the Appalachian basin of New York State allow refinement of thermal maturity maps for Ordovician and Devonian rocks. CAI isotherms on the new maps show a pattern that approximates that published by Harris et al. (1978) in eastern and western New York, but it differs in central New York, where the isotherms are shifted markedly westward by more than 100 km and are more tightly grouped. This close grouping of isograds reflects a steeper thermal gradient than previously noted by Harris et al. (1978) and agrees closely with the abrupt west-to-east increase in thermal maturity across New York noted by Johnsson (1986)....
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This new series of maps enhances previous thermal maturity maps in Pennsylvania by establishing: 1) new subsurface CAI data points for the Ordovician and Devonian and 2) new %Ro and Rock Eval subsurface data points for Middle and Upper Devonian black shale units. Thermal maturity values for the Ordovician and Devonian strata are of major interest because they contain the source rocks for most of the oil and natural gas resources in the basin. Thermal maturity patterns of the Middle Ordovician Trenton Group are evaluated here because they closely approximate those of the overlying Ordovician Utica Shale that is believed to be the source rock for the regional oil and gas accumulation in Lower Silurian sandstones and...
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Abundant Mesoproterozoic A-type granitoid rocks of two intrusive suites underlie approximately 50 percent of the New Jersey Highlands. These rocks, the Byram Intrusive and Lake Hopatcong Intrusive Suites, consist of granite, alaskite, quartz monzonite, monzonite, and minor pegmatite. Byram and Lake Hopatcong rocks, although different mineralogically, are similar geochemically and contain overlapping abundances of most major and trace elements. Petrographic relationships, geochronology, field relationships, and geochemical similarities support a comagmatic origin for both suites. They constitute the here named Vernon Supersuite.
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Seismic-hazard evaluations in the eastern United States must be based on interpretations of the composition and form of Proterozoic basement-rock terranes and overlying Paleozoic strata, and on factors that can cause relative movements among their units, rather than Phanerozoic orogenic structures, which may be independent of modern tectonics. The tectonic-province concept is a major part of both probabilistic and deterministic seismic-hazard evaluations, yet those that have been proposed to date have not attempted to geographically correlate modern earthquakes with regional basement structure. Comparison of basement terrane (megablock) boundaries with the spatial pattern of modern seismicity may lead to the mechanically...
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The Shell 410-1 well is the most downdip (seaward) hydrocarbon exploratory well in the Georges Bank Basin. It was drilled to a total depth of 4745 m RKB, and penetrated a section composed of Middle Jurassic to Quaternary sedimentary rocks. The lithostratigraphy of the section is described. The strata penetrated by the Shell 410-1 well are more marine than rocks at the updip (landward) COST G-1, Exxon 975-1, COST G-2, and Conoco 145-1 well sites. Limestones and calcareous mudstones dominate at the Shell 410-1 site. Dolomite and anhydrite are much more abundant in the Bajocian-Callovian strata of the Shell 410-1 well, which is evidence that the carbonate-bank palaeoenvironments recorded in the Iroquois and Abenaki...
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Felsite dikes in the Rittenhouse Gap iron mine district of the Reading Prong, eastern Pennsylvania, have a close geochemical affinity with the peralkaline Battle Mountain Member of the Robertson River Igneous Suite (RRIS), northern Virginia. These newly recognized Rittenhouse Gap Felsite dikes of the Swabia Creek Igneous Suite (SCIS) of eastern Pennsylvania plot as within-plate, A-type, A1 granites on various discriminant diagrams, but are quite distinct from late Neoproterozoic Catoctin Metarhyolite of Pennsylvania which has lower Ga/Al and Nb, but higher Eu. Newly recognized metadiabase dikes, also found in the Rittenhouse Gap district and proposed as Tunnel Mine Metadiabase of the SCIS, classify as alkali within-plate...
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Pioneers named El Dorado, Kansas, in 1857 for the beauty of the site and the promise of future riches but not until 58 years later was black rather than mythical yellow gold discovered when the Stapleton No. 1 oil well came in on October 5, 1915. El Dorado's leaders were envious when nearby towns found huge gas fields and thrived. John Donley, an El Dorado barber, had tried to find either gas or oil in 1878 at a nearby site selected by a spiritualist. He staked out a townsite, spudded a well and drilled 200 feet before running out of money. Wells in 1879 and 1882 produced only brine. In June, 1914, chafed over discovery of oil in nearby Augusta, El Dorado city fathers contracted with Erasmus Haworth, soon to retire...
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The occurrence, distribution, and temporal patterns of pesticide concentrations were studied in the Hudson River Basin during 1994 - 96. This article presents the results of three separate pesticide studies conducted as part of the U.S. Geological Survey (USGS) National Water Quality Assessment (NAWQA) program. Pesticides were found in all three studies, but rarely at concentrations exceeding any U.S. Environmental Protection Agency drinking-water standards. The highest concentrations were detected during and immediately after the first runoff following pesticide applications in the late spring and early summer. The herbicides atrazine and metolachlor were the most commonly detected pesticides and were present in...
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The Bald Friar Metabasalt (BFM) and Kennett Square Amphibolite (KSA) are basaltic units found in the Piedmont of southeastern Pennsylvania. The BFM is also recognized in northern Maryland. Both are believed to represent fragments of the floor of the Iapetus Ocean, but are not known occur in direct association with one another. The BFM typically occurs as small fragments having typical stratigraphic thicknesses of 2.5 m, and composed of greenish, fine-grained chlorite-epidote-actinolite-albite metabasalt in ophiolite me??lange. One bed of pillow basalt has been found at the type locality, Bald Friar, Cecil County, Maryland. Even though outcrops of BFM are highly discontinuous, they have a remarkable chemical uniformity...
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The bedrock of the Windham quadrangle in southeastern New Hampshire consists of deformed early Palaeozoic crystalline metamorphic and intrusive igneous rocks intruded by Mesozoic igneous dikes. Generally, less common northeast striking, steeply dipping fractures developed sub-parallel to the pre-existing tectonic foliation in the Palaeozoic rocks. Mesozoic lamprophyre and diabase dikes intruded along the northeast trending fractures, utilizing the pre-existing anisotropy in the crystalline rocks. Northwest striking, steeply dipping systematic joints and joint sets are the most prominent fractures in the area and, at least in part, post-date the Mesozoic dikes. Sub-horizontal sheeting joints occur in all rock types....
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Cores collected during recent drilling in western Cape Cod, Massachusetts provide insight into the topography and petrology of the underlying bedrock. 62 drill sites spread over a ???140 km2 study area produced cores of granitoids (31), orthogneisses (20), basalts/diabases (4), amphibolites (3), felsic mylonites (2), and dolomitic rock (2). Granitoid cores range in composition from granite to tonalite to quartz diorite, but are dominated by single-mica granites. Alteration is common in nearly all cores examined in this study, and is evidenced by the secondary growth of chlorite and epidote. The granitoids resemble rocks of the Dedham and Fall River terranes (Wones and Goldsmith 1991). Gneisses from the study area...