Geology of south-central Alaska
Warren J. Nokleberg, George Plafker, Frederic H. Wilson
1994, Book chapter, The geology of Alaska: Volume G-1 of Decade of North American Geology
South-central Alaska is defined as the region bounded by the Kuskokwim Mountains to the northwest, the basins north of the Alaska Range to the north, the Canadian border to the east, and the Chugach Mountains to the south (Fig. 1). This region, hereafter called the study area, includes the Alaska...
Geology of Seward Peninsula and Saint Lawrence Island
Alison B. Till, Julie A. Dumoulin
1994, Book chapter, The geology of Alaska: Volume G-1 of Decade of North American Geology
Seward Peninsula (Fig. 1) may be divided into two geologic terranes (Fig. 2) on the basis of stratigraphy, structure, and metamorphic history. The Seward terrane, an area 150 by 150 km in the central and eastern peninsula, is dominated by Precambrian(?) and early Paleozoic blueschist-, greenschist-, and amphibolite-facies schist and...
Use of boreal forested wetlands by Pacific loons (Gavia pacifica Lawrence) and horned grebes (Podiceps auritus L.): Relations with limnological characteristics
P.J. Heglund, J.R. Jones, L.H. Fredrickson, M.S. Kaiser
1994, Book chapter, Developments in Hydrobiology: Aquatic birds in the trophic web of lakes: Proceedings of a symposium held in Sackville, New Brunswick, Canada, in August 1991
Our objective was to determine if the occurrence and abundance of Pacific loons (Gavia pacifica Lawrence) and horned grebes (Podiceps auritus L.) on 123 wetlands of Yukon Flats National Wildlife Refuge in east central Alaska were related to the limnological characteristics of those wetlands. Aquatic bird-wetland...
Relaxation of the south flank after the 7.2-magnitude Kalapana earthquake, Kilauea Volcano, Hawaii
John J. Dvorak, Fred W. Klein, Donald A. Swanson
1994, Bulletin of the Seismological Society of America (84) 133-141
An M = 7.2 earthquake on 29 November 1975 caused the south flank of Kilauea Volcano, Hawaii, to move seaward several meters: a catastrophic release of compression of the south flank caused by earlier injections of magma into the adjacent segment of a rift zone. The focal mechanisms of the...
Tonsteins and clay-rich layers in coal-bearing intervals of the Eocene Manning formation, east-central Texas
Leslie F. Ruppert, Peter D. Warwick, Sharon S. Crowley, James Pontolillo
1994, Gulf Coast Association of Geological Societies Transactions (44) 649-656
Six samples from clay-rich intervals in the coal-bearing upper part of the Eocene Manning Formation were analyzed by scanning-electron microscopy and energy-dispersive X-ray fluorescence to determine the origin of minerals in the samples. Two samples were from surface-mine exposures of the 3500 coal bed near Bryan, Texas, and the remaining...
Seismic images of a tectonic subdivision of the Greenville Orogen beneath lakes Ontario and Erie
D. A. Forsyth, Bernd Milkereit, A. Davidson, S. Hanmer, Deborah R. Hutchinson, W. J. Hinze, R.F. Mereu
1994, Canadian Journal of Earth Sciences (31) 229-242
New seismic data from marine air-gun and Vibroseis profiles in Lake Ontario and Lake Erie provide images of subhorizontal Phanerozoic sediments underlain by a remarkable series of easterly dipping reflections that extends from the crystalline basement to the lower crust. These reflections are interpreted as structural features of crustal-scale subdivisions...
Deep structure beneath Lake Ontario: Crustal-scale Grenville subdivisions
D. A. Forsyth, Bernd Milkereit, Colin A. Zelt, D. J. White, R. M. Easton, Deborah R. Hutchinson
1994, Canadian Journal of Earth Sciences (31) 255-270
Lake Ontario marine seismic data reveal major Grenville crustal subdivisions beneath central and southern Lake Ontario separated by interpreted shear zones that extend to the lower crust. A shear zone bounded transition between the Elzevir and Frontenac terranes exposed north of Lake Ontario is linked to a seismically defined shear...
Chaotic deposition by a giant wave, Molokai, Hawaii
J.G. Moore, W.B. Bryan, K.R. Ludwig
1994, Geological Society of America Bulletin (106) 962-967
A coral-basalt breccia-conglomerate is exposed >60m above present sea level and nearly 2km inland from the present shoreline on the southwest side of East Molokai Volcano. This deposits was apparently laid down by a giant wave that broke over an outer reef, similar to the present fringing reef, and advanced...
Late Mesozoic and possible early Tertiary accretion in western Washington State: The Helena-Haystack mélange and the Darrington-Devils Mountain fault zone
R. W. Tabor
1994, Geological Society of America Bulletin (106) 217-232
The Helena-Haystack mélange (HH mélange) and coincident Darrington-Devils Mountain fault zone (DDMFZ) in northwestern Washington separate two terranes, the Northwest Cascade System (NWCS) and the western and eastern mélange belts (WEMB). The two terranes of Paleozoic and Mesozoic rocks superficially resemble each other but record considerable differences in structural and...
Atmospheric circulation and snowpack in the Gunnison River Basin
Gregory J. McCabe
1994, Conference Paper, Proceedings of the 21st Annual Conference on Water Policy and
Winter mean 700-millibar height anomalies over the eastern North Pacific Ocean and the western United States are related to variability in snowpack accumulations measured on or about April 1 in the Gunnison River Basin in Colorado. Higher-than-average snowpack accumulations are associated with negative 700-millibar height anomalies (anomalous cyclonic circulation) over...
Zinc, copper, and lead in mid-ocean ridge basalts and the source rock control on Zn/Pb in ocean-ridge hydrothermal deposits
B. R. Doe
1994, Geochimica et Cosmochimica Acta (58) 2215-2223
The contents of Zn, Cu, and Pb in mid-ocean ridge basalts (MORB) and the MORB source-rock control on Zn/Pb in ocean-ridge hydrothermal deposits are examined. The values of Zn, Cu, and Pb for submarine mid-ocean ridge basalts (MORB) are, respectively (in ppm): average MORB—75, 75, and 0.7; West Valley, Juan...
Origin of phenocrysts and compositional diversity in pre-Mazama rhyodacite lavas, Crater Lake, Oregon
S. Nakada, C. R. Bacon, A.E. Gartner
1994, Journal of Petrology (35) 127-162
Phenocrysts in porphyritic volcanic rocks may originate in a variety of ways in addition to nucleation and growth in the matrix in which they are found. Porphyritic rhyodacite lavas that underlie the eastern half of Mount Mazama, the High Cascade andesite/dacite volcano that contains Crater Lake caldera, contain evidence that...
Dissolution of bedded rock salt: A seismic profile across the active eastern margin of the Hutchinson Salt Member, central Kansas
N.L. Anderson, J. Hopkins, A. Martinez, R.W. Knapp, P. A. Macfarlane, W.L. Watney, R. Black
1994, Computers & Geosciences (20) 889-903
Since late Tertiary, bedded rock salt of the Permian Hutchinson Salt Member has been dissolved more-or-less continuously along its active eastern margin in central Kansas as a result of sustained contact with unconfined, undersaturated groundwater. The associated westward migration of the eastern margin has resulted in surface subsidence and the...
Two episodes of meltwater influx from glacial Lake Agassiz into the Lake Michigan basin and their climatic contrasts
Steven M. Colman, L.D. Keigwin, R. M. Forester
1994, Geology (22) 547-550
Two episodes of meltwater influx from glacial Lake Agassiz are recorded as prominent sedimentologic, isotopic, magnetic, and faunal signatures in southern Lake Michigan profundal sediments. As a tributary to the main path of eastward Lake Agassiz flow, southern Lake Michigan recorded only the largest, catastrophic discharges. The distinctive Wilmette Bed,...
In search of earthquake-related hydrologic and chemical changes along Hayward Fault
C.-Y. King, D. Basler, T. S. Presser, William C. Evans, L. D. White, A. Minissale
1994, Applied Geochemistry (9) 83-91
Flow and chemical measurements have been made about once a month, and more frequently when required, since 1976 at two springs in Alum Rock Park in eastern San Jose, California, and since 1980 at two shallow wells in eastern Oakland in search of earthquake-related changes. All sites are on or...
Submerged and eroded drumlins off northeastern Massachusetts
R. N. Oldale, H.J. Knebel, Michael H. Bothner
1994, Geomorphology (9) 301-309
Streamlined, oval-shaped, oriented topographic highs in Massachusetts Bay are identified as the erosional remnants of drumlins. The topographic highs correlate with outlines of lag gravel deposits on the sea floor and both the highs and lag gravel seafloor footprint have a distinct east-southeast long axis trend. This trend is similar...
The geologic framework of southern Lake Michigan
D.S. Foster, D. W. Folger
1994, Journal of Great Lakes Research (20) 44-60
The bathymetry is controlled by the underlying bedrock. Bedrock comprises Silurian dolomite and Devonian limestone and shale. Quaternary sediment, 10 to 40 m thick, overlies bedrock. From Waukegan, Illinois, south to Indiana Harbor, the bottom is floored by till, sand, pebbles, and cobbvles. The lake floor is erosional or nondepositional...
Unusual ice diamicts emplaced during the December 15, 1989 eruption of Redoubt volcano, Alaska
R. B. Waitt, C. A. Gardner, T.C. Pierson, J. J. Major, C.A. Neal
1994, Journal of Volcanology and Geothermal Research (62) 409-428
Ice diamict comprising clasts of glacier ice and subordinate rock debris in a matrix of ice (snow) grains, coarse ash, and frozen pore water was deposited during the eruption of Redoubt Volcano on December 15, 1989. Rounded clasts of glacier ice and snowpack are as large as 2.5 m, clasts...
Coal resources, production, and quality in the Eastern kentucky coal field: Perspectives on the future of steam coal production
J.C. Hower, J.K. Hiett, G.D. Wild, C.F. Eble
1994, Nonrenewable Resources (3) 216-236
The Eastern Kentucky coal field, along with adjacent portions of Virginia and southern West Virginia, is part of the greatest production concentration of high-heating-value, low-sulfur coal in the United States, accounting for over 27% of the 1993 U.S. production of coal of all ranks. Eastern Kentucky's production is spread among...
Testing an automated method to estimate ground-water recharge from streamflow records
A. T. Rutledge, C.C. Daniel
1994, Groundwater (32) 180-189
The computer program, RORA, allows automated analysis of streamflow hydrographs to estimate ground-water recharge. Output from the program, which is based on the recession-curve-displacement method (often referred to as the Rorabaugh method, for whom the program is named), was compared to estimates of recharge obtained...
Deglaciation, lake levels, and meltwater discharge in the Lake Michigan basin
Steven M. Colman, J.A. Clark, L. Clayton, A.K. Hansel, C.E. Larsen
1994, Quaternary Science Reviews (13) 879-890
The deglacial history of the Lake Michigan basin, including discharge and routing of meltwater, is complex because of the interaction among (1) glacial retreats and re-advances in the basin (2) the timing of occupation and the isostatic adjustment of lake outlets and (3) the depositional and erosional processes that left...
Lead isotope compositions as guides to early gold mineralization: The North Amethyst vein system, Creede district, Colorado
Nora K. Foley, Robert A. Ayuso
1994, Economic Geology (89) 1842-1859
The North Amethyst vein system, which is hosted by approximately 27 Ma Carpenter Ridge Tuff and approximately 26 Ma Nelson Mountain Tuff, has two mineral associations separated by brecciation and sedimentation in the veins. The early association consists of quartz, rhodonite, hematite, magnetite, electrum (Au (sub 0.3-0.5) Ag (sub...
Climate, interseasonal storage of soil water, and the annual water balance
P. C. D. Milly
1994, Advances in Water Resources (17) 19-24
The effects of annual totals and seasonal variations of precipitation and potential evaporation on the annual water balance are explored. It is assumed that the only other factor of significance to annual water balance is a simple process of water storage, and that the relevant storage capacity is the plant-available...
Geochemistry of tectonically expelled fluids from the northern Coast ranges, Rumsey Hills, California, USA
M.L. Davisson, T. S. Presser, R.E. Criss
1994, Geochimica et Cosmochimica Acta (58) 1687-1699
Tectonic compression has created abnormally high pressure on deep basinal fluids causing their expulsion from areally exposed Upper Cretaceous rock along the eastern margin of the California Coast ranges. The fluids emerge as near-neutral, perennial sodium chloride springs at high elevations with flow rates as high as 10 L per...
Principal facts for gravity data in the Bethel and Russian Mission 1 degree x 3 degrees quadrangles, Alaska
Robert L. Morin
1994, Open-File Report 94-14-A
Bethel and Russian Mission 1° x 3° quadrangles are located in southwestern Alaska near the mouth of the Kuskokwim River. The Russian Mission quadrangle now has about 266 gravity stations and the Bethel quadrangle has about 485 gravity stations.Riverboat traverses along the Yukon River in the northern part of the...
