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William J. Perry

Publications and source records attributed to William J. Perry.

At least 19 recordsLinked to original sources
USGS2021

Recursive Bayesian computation facilitates adaptive optimal design in ecological studies

Optimal design procedures provide a framework to leverage the learning generated by ecological models to flexibly and efficiently deploy future monitoring efforts. At the same time, Bayesian hierarchical models have become widespread in ecology and offer a rich set of tools for ecological learning and inference. However, coupling these methods with an optimal design framework can become computationally intractable. Recursive Bayesian computation offers a way to substantially reduce this computational burden, making optimal design accessible for modern Bayesian ecological models. We demonstrate the application of so-called prior-proposal recursive Bayes to optimal design using a simulated data binary regression and the real-world example of monitoring and modeling sea otters in Glacier Bay, Alaska. These examples highlight the computational gains offered by recursive Bayesian methods and the tighter fusion of monitoring and science that those computational gains enable.

Ecology↗
USGS2021

Loss of ice cover, shifting phenology, and more extreme events in Northern Hemisphere lakes

Long-term lake ice phenological records from around the Northern Hemisphere provide unique sensitive indicators of climatic variations, even prior to the existence of physical meteorological measurement stations. Here, we updated ice phenology records for 60 lakes with time-series ranging from 107–204 years to provide the first re-assessment of Northern Hemispheric ice trends since 2004 by adding 15 additional years of ice phenology records and 40 lakes to our study. We found that, on average, ice-on was 11.0 days later, ice-off was 6.8 days earlier, and ice duration was 17.0 days shorter per century over the entire record for each lake. Trends in ice-on and ice duration were six times faster in the last 25-year period (1992–2016) than previous quarter centuries. More extreme events in recent decades, including late ice-on, early ice-off, shorter periods of ice cover, or no ice cover at all, contribute to the increasing rate of lake ice loss. Reductions in greenhouse gas emissions could limit increases in air temperature and abate losses in lake ice cover that would subsequently limit ecological, cultural, and socioeconomic consequences, such as increased evaporation rates, warmer water temperatures, degraded water quality, and the formation of toxic algal blooms.

Journal of Geophysical Research: Biogeosciences↗
USGS2004

Tertiary thrust systems and fluid flow beneath the Beaufort coastal plain (1002 area), Arctic National Wildlife Refuge, Alaska, U.S.A.

Beneath the Arctic coastal plain (commonly referred to as "the 1002 area") in the Arctic National Wildlife Refuge, northeastern Alaska, United States, seismic reflection data show that the northernmost and youngest part of the Brookian orogen is preserved as a Paleogene to Neogene system of blind and buried thrust-related structures. These structures involve Proterozoic to Miocene (and younger?) rocks that contain several potential petroleum reservoir facies. Thermal maturity data indicate that the deformed rocks are mature to overmature with respect to hydrocarbon generation. Oil seeps and stains in outcrops and shows in nearby wells indicate that oil has migrated through the region; geochemical studies have identified three potential petroleum systems. Hydrocarbons that were generated from Mesozoic source rocks in the deformed belt were apparently expelled and migrated northward in the Paleogene, before much of the deformation in this part of the orogen. It is also possible that Neogene petroleum, which was generated in Tertiary rocks offshore in the Arctic Ocean, migrated southward into Neogene structural traps at the thrust front. However, the hydrocarbon resource potential of this largely unexplored region of Alaska's North Slope remains poorly known. In the western part of the 1002 area, the dominant style of thin-skinned thrusting is that of a passive-roof duplex, bounded below by a detachment (floor thrust) near the base of Lower Cretaceous and younger foreland basin deposits and bounded above by a north-dipping roof thrust near the base of the Eocene. East-west-trending, basement-involved thrusts produced the Sadlerochit Mountains to the south, and buried, basement-involved thrusts are also present north of the Sadlerochit Mountains, where they appear to feed displacement into the thin-skinned system. Locally, late basement-involved thrusts postdate the thin-skinned thrusting. Both the basement-involved thrusts and the thin-skinned passive-roof duplex were principally active in the Miocene. In the eastern part of the 1002 area, a northward-younging pattern of thin-skinned deformation is apparent. Converging patterns of Paleocene reflectors on the north flank of the Sabbath syncline indicate that the Aichilik high and the Sabbath syncline formed as a passive-roof duplex and piggyback basin, respectively, just behind the Paleocene deformation front. During the Eocene and possibly the Oligocene, thin-skinned thrusting advanced northward over the present location of the Niguanak high. A passive-roof duplex occupied the frontal part of this system. The Kingak and Hue shales exposed above the Niguanak high were transported into their present structural position during the Eocene to Oligocene motion on the long thrust ramps above the present south flank of the Niguanak high. Broad, basement-cored subsurface domes (Niguanak high and Aurora dome) formed near the deformation front in the Oligocene, deforming the overlying thin-skinned structures and feeding a new increment of displacement into thin-skinned structures directly to the north. Deformation continued through the Miocene above a detachment in the basement. Offshore seismicity and Holocene shortening documented by previous workers may indicate that contractional deformation continues to the present day.

Alaska↗
USGS2002

Late Cenozoic deformation by evaporite tectonism in the Grand Hogback monocline, southwest of the White River uplift, Colorado

Along 50 km of the complex, southwest-dipping, Laramide Grand Hogback monocline, which wraps around the southwest flank of the White River uplift in westcentral Colorado, detailed mapping provides evidence of late Cenozoic collapse that resulted from subsurface flow, diapirism, and dissolution of Pennsylvanian Eagle Valley Evaporite. Numerous discontinuous, small-amplitude, strike-parallel folds and steeply dipping faults that overlie the evaporite are interpreted as the result of both flow-induced and dissolution-induced collapse and diapirism concentrated along cross-strike, radial valleys draining the uplift. Folding of an immature Pliocene conglomerate into a tight syncline by collapse into an underlying diapir emphasizes the young age of evaporite tectonism. Major evaporite diapirs in valleys penetrate overlying Pennsylvanian Eagle Valley and Pennsylvanian-Permian Maroon Formations. In the absence of a Miocene basaltic datum used to quantify collapse elsewhere in west-central Colorado, we quantify removal of evaporite by contrasting estimated original evaporite thicknesses with thicknesses of remaining evaporite based on surface structural control and cross section construction. We estimate that ∼40 km3 of evaporite were removed along the southwest flank, the majority of which came from cross-strike valleys and a minority from intervening drainage divides. The mechanism for initiation of flow of evaporite is interpreted to be late Cenozoic regional uplift and accompanying deep incision of valleys draining the White River uplift. Unloading of evaporite beneath these valleys channeled evaporite to flow northward up dip to diapirically extrude from overlying Maroon and Eagle Valley Formations. Laramide monoclinal structures change gradually along strike from a single monocline, which produced a complexly folded back thrust, to double monoclines stacked on one another, which are located close to bends in the flank of the uplift.

Colorado↗
USGS2002

Implications for evaporite tectonism in the Carbondale and Eagle collapse centers of west-central Colorado, based on reprocessed seismic reflection data

Reprocessing of approximately 64 km of seismic reflection data along five seismic lines has led to new interpretations of evaporite tectonism associated with the Pennsylvanian Eagle Valley Evaporite of the central Colorado trough. Evidence of the oldest evaporite tectonism in the region, imaged by the seismic data, occurs in the Eagle collapse center at Hardscrabble Mountain. Here, the Triassic-Permian State Bridge Formation is abnormally thick, reflecting an outflow of underlying evaporite. On the west side of the Carbondale collapse center, structural wedging formed the west-dipping Grand Hogback monocline during early Tertiary Laramide deformation close to the western margin of the late Paleozoic central Colorado trough. Uplimb thrusts beneath the steep face of the monocline provide evidence of backthrusting. The presence of the Roaring Fork diapir proximal to the point of greatest curvature of the Grand Hogback monocline at the Leadville reflector level suggests that diapirism may have begun during formation of the monocline. Evidence for late Cenozoic evaporite tectonism is observed in all the seismic lines in spite of the difficulty of imaging shallow, young deposits that record evidence of abundant late Cenozoic evaporite tectonism observed during geologic mapping.

Colorado↗
USGS2002

Evaporite tectonism in the lower Roaring Fork River valley, west-central Colorado

Evaporite tectonism in the lower Roaring Fork River valley in west-central Colorado has caused regional subsidence of a differentially downdropped area in the southern part of the Carbondale collapse center during the late Cenozoic. A prominent topographic depression coincides with this collapse area, and drainage patterns within the collapse area contrast sharply with those outside of it. Miocene volcanic rocks are downdropped as much as 1220 m in the collapse area. Much of the structural lowering occurred along the margins of the collapse area. Major Laramide-age structures bound the east and west sides of the collapse area, but movement on these structures during late Cenozoic collapse was in an opposite direction to their Laramide movement. Within the interior part of the collapse area faults and folds have as much as 300 m of structural relief. Large blocks of rock may be rafting into the Roaring Fork River valley as underlying evaporite flows toward the valley. Sinkholes are common in the collapse area, as are closed, or nearly closed, structurally controlled topographic depressions that are formed in both surficial deposits and bedrock. Upper Cenozoic deltaic and lacustrine deposits preserved on ridgelines and mesas document the positions of former structural depressions that were initially filled with sediments and later breached by erosion. At least 450 m of syn-collapse sediments accumulated in a collapse depression on the north side of Mount Sopris. Complexly deformed and brecciated deposits in the interior parts of the collapse center are interpreted as collapse debris. Evaporite flow is an important element in the collapse process, and during early stages of collapse it was perhaps the primary means of deformation. Flow by itself, does not remove evaporite from the collapse area. Dissolution and accompanying transport of dissolved constituents by groundwater and surface water are the ultimate means by which evaporite exits the collapse area. Collapse continues today, as evidenced by historic sinkholes and modern high-salinity loads in rivers and thermal springs. Thick evaporite deposits still underlie much of the collapse area, so collapse will likely continue in the future.

Colorado↗
USGS2000

Geologic map of the Lima 30’ x 60’ quadrangle, southwest Montana

This geologic map represents a compilation of mostly previously unpublished maps by numerous authors. The map is divided into three areas of responsibility: 1) the Tendoy Mountains and western Centennial Mountains, mapped and compiled by Betty Skipp, Susanne Janecke, and Bill Perry (Part A); 2) the Snowcrest Range, mapped by Edward T. Ruppel (Part B), and 3) the remainder of the area, including the Sage Creek basin, the Red Rock Hills, the Blacktail Range, and the Upper Blacktail Deer Creek valley, compiled and mapped by Jeff Lonn and Jim Sears, with data also contributed by Bill Fritz, Hugh Hurlow, and Rob Thomas (Part C). Figure 1 shows mapping responsibilities. The geologic map (Plate 1) is accompanied by this text pamphlet describing map units for each of the three areas. The same lithologic distinctions among units and the same unit labels were used where possible, usually where formal stratigraphic nomenclature existed, but each area has its own informal Tertiary and Quaternary stratigraphy. References are also given separately in each section. However, correlation diagrams for each of the three areas are shown in a single Correlation Chart for the whole quadrangle (Figure 2). Plate 2, at the same scale, is provided in order to show more readily the names being applied to specific faults and folds, particularly in the Tendoy Mountains and western Centennial Mountains.

Montana↗
USGS1996

Possible continuous-type (unconventional) gas accumulation in the Lower Silurian "Clinton" sands, Medina Group and Tuscarora Sandstone in the Appalachian Basin; a progress report of the 1995 project activities

INTRODUCTION: In the U.S. Geological Survey's (USGS) 1995 National Assessment of United States oil and gas resources (Gautier and others, 1995), the Appalachian basin was estimated to have, at a mean value, about 61 trillion cubic feet (TCF) of recoverable gas in sandstone and shale reservoirs of Paleozoic age. Approximately one-half of this gas resource is estimated to reside in a regionally extensive, continuous-type gas accumulation whose reservoirs consist of low-permeability sandstone of the Lower Silurian 'Clinton' sands and Medina Group (Gautier and others, 1995; Ryder, 1995). Recognizing the importance of this large regional gas accumulation for future energy considerations, the USGS initiated in January 1995 a multi-year study to evaluate the nature, distribution, and origin of natural gas in the 'Clinton' sands, Medina Group sandstones, and equivalent Tuscarora Sandstone. The project is part of a larger natural gas project, Continuous Gas Accumulations in Sandstones and Carbonates, coordinated in FY1995 by Ben E. Law and Jennie L. Ridgley, USGS, Denver. Approximately 2.6 man years were devoted to the Clinton/Medina project in FY1995. A continuous-type gas accumulation, referred to in the project, is a new term introduced by Schmoker (1995a) to identify those natural gas accumulations whose reservoirs are charged throughout with gas over a large area and whose entrapment does not involve a downdip gas-water contact. Gas in these accumulations is located downdip of the water column and, thus, is the reverse of conventional-type hydrocarbon accumulations. Commonly used industry terms that are more or less synonymous with continuous-type gas accumulations include basin- centered gas accumulation (Rose and others, 1984; Law and Spencer, 1993), tight (low-permeability) gas reservoir (Spencer, 1989; Law and others, 1989; Perry, 1994), and deep basin gas (Masters, 1979, 1984). The realization that undiscovered gas in Lower Silurian sandstone reservoirs of the Appalachian basin probably occurs in a continuous accumulation rather than in conventionally trapped, discrete accumulations represents a significant departure from the 1989 National Assessment (Mast and others, 1989; deWitt, 1993). In 1989, a direct assessment (field-size distributions required for play analysis were unavailable) of the Lower Silurian sandstone play gave, at a mean value, about 1.7 TCF of gas. The 1995 estimate (~30 TCF of gas) is so much greater than the 1989 estimate (~1.7 TCF of gas) because of the interpreted continuous nature of the accumulation and the assessment methodology applied. The methodology for continuous hydrocarbon accumulations assumes that the reservoirs in the accumulation are gas-saturated and takes into account: 1) estimated ultimate recovery (EUR) per well probability distributions, 2) optimum area that a well can drain (spacing), 3) number of untested drill sites having the appropriate spacing area, 4) success ratio of previously drilled holes, and 5) risk (Schmoker, 1995b). Davis (1984), Zagorski (1988, 1991), and Law and Spencer (1993) were among the first petroleum geologists to suggest that gas in the 'Clinton' sands and Medina Group sandstones was trapped in a basin-centered/deep basin accumulation. They recognized many of the earmarks of a basin-centered/deep basin accumulation such as low-permeability reservoirs, abnormally low formation pressure, coalesced gas fields, gas shows or production in most holes drilled, low water yields, and a general lack of structural control on entrapment. Ryder (1995) adopted this interpretation by defining four continuous-type gas plays (6728-6731) in the 'Clinton' sands-Medina Group interval (fig.1). Play 6728 (Clinton/Medina sandstone gas high potential) covers a 17,000 sq mi region of western New York, northwestern Pennsylvania, eastern Ohio, and a small part of westernmost West Virginia that is very favorable for future gas resources (fig.1). Also, this play includes a l

Open-File Report↗
USGS1989

Structural evolution of the southeastern portion of the Anadarko Basin region

Field investigations in the Lake Classen-Turner Falls, Oklahoma, area of the northern Arbuckle anticline, on the southeastern margin of the Anadarko basin, indicate that transpressional (oblique compressional) deformation of Late Pennsylvanian age dominated the structural development of this area. The Arbuckle anticline is detached along the NW -trending, SW -dipping, left-reverse Arbuckle fault and is thrust obliquely onto the margin of the Tishomingo block to the east. Paleostress analysis of slip lines on mesoscopic faults along the northeastern limb of the Arbuckle anticline, associated in style and geometry with oblique Arbuckle thrusting, indicates compression directed N. 35-60° E.

Oklahoma↗
USGS1978

Mineral resources of the Cranberry Wilderness Study Area, Pocahontas and Webster counties, West Virginia

Cranberry Wilderness Study Area comprises 14,702 ha in the Monongahela National Forest, Pocahontas and Webster Counties, east-central West Virginia. The area is in the Yew Mountains of the Appalachian Plateaus and is at the eastern edge of the central Appalachian coal fields. Cranberry Glades, a peatland of botanical interest lies at the southern end of the study area. All surface rights in the area are held by the U. S. Forest Service; nearly 90 percent of the mineral rights are privately-owned or subordinate to the surface rights.

West Virginia↗
USGS1975

Palynological and stratigraphic investigations of four deep wells in the Salisbury Embayment of the Atlantic Coastal Plain

Use of palynological zones defined by Brenner and Doyle from the Cretaceous outcrop belt in Maryland, Delaware, and New Jersey permit correlation of the Cretaceous section in four wells drilled to basement in the Salisbury Embayment in the Eastern Shore of Maryland and in Accomack Co., Virginia. These correlations, supplemented by electric log correlations between wells, clarify the Mesozoic depositional history of the outer margin of the Atlantic Coastal Plain. The bulk of the Cretaceous section consists of continental to marginal is marine sediments correlative with and probably older than the outcrop Potomac Group (Aptian-lower Cenomanian?). Lower Cretaceous palynlogical assemblages also occur in at least the top of basal "red beds" considered Triassic or Jurassic by earlier authors. Dinoflagellates and lithological criteria indicate several transgressive-regressive cycles within the generally transgressive Potomac sequence, with maximum marine incursions in the Late Albian and the Early Cenomanian. Equivalents of the lower Raritan Formation of New Jersey (middle-upper Cenomanian?), absent at the Maryland outcrop, are recognized for the first time in the Taylor and Bethards wells. Potomac and lower Raritan equivalents are separated from overlying Magothy equivalents (upper Santonian-lower Campanian) by a major regional unconformity. Well data suggest that further downdip, under the continental shelf, most of the formations should be marine and contain abundant organic matter. Given sufficient heat and trapping structures, oil and gas may have accumulated.

Open-File Report↗
USGS1975

Tectonics of the western Valley and Ridge foldbelt, Pendleton County, West Virginia - a summary report

A belt of high anticlines, the Nittany anticlinorium, occupies the western Valley and Ridge foldbelt in the central Appalachians. It extends southwestward from the Nittany arch of central Pennsylvania into the Virginias. An investigation of the tectonics of this anticlinorium in Pendleton County, W. Va., rules out active basement involvement in the deformation of the area. Cross-sectional models consistent with the accumulated data show that Middle Cambrian through Middle Ordovician carbonate rocks are technically stacked, shingle-fashion, from southeast to northwest below predominantly folded younger strata that have undergone less lateral shortening. Differential shortening in this area is of the proper order to balance cover deformation in the Allegheny synclinorium to the west. Field relations suggest a long period of abnormally high fluid pressures in Lower Devonian and older strata during deformation. At this time, the area was under sufficient northwest, near-horizontal compressive stress for abundant quartz deformation lamellae to form. Gravity sliding is ruled out as the deforming mechanism for this part of the Appalachian foldbelt. No significant tectonism appears to have occurred prior to Pennsylvanian time in this area.

West Virginia↗