Stratigraphic and structural synthesis of a Miocene extensional terrane, southeast California and west-central Arizona
Jane E. Nielson, Kathi K. Beratan
1995, Bulletin of the Geological Society of America (107) 241-252
Detailed stratigraphy and isotopic dating of stratigraphic sections in the Colorado River extensional corridor support a regional correlation of highly faulted Tertiary stratigraphic sequences and provide a chronologic framework for interpreting the evolution of low-angle normal (detachment) faults. On the basis of this correlation, we define six tilting domains in...
Upper Eocene impactites of the U.S. East Coast; depositional origins, biostratigraphic framework, and correlation
C. Wylie Poag, Marie-Pierre Aubry
1995, Palaios (10) 16-43
Similar successions of planktonic foraminifera, calcareous nannofossils, and bolboformids document coeval deposition of the Exmore impact breccia (Virginia Coastal Plain) and an impact ejecta layer at DSDP Site 612 (New Jersey Continental Slope). Both impactites accumulated in the late Eocene during the early part of biochrons P15 (planktonic foraminifera) and...
Spatial and temporal patterns of late quaternary eolian deposition, Eastern Colorado, U.S.A
Richard F. Madole
1995, Quaternary Science Reviews (14) 155-177
Eolian sediment covers about 60% of Colorado east of the Rocky Mountains; about 30% of the sediment is sand and 70% is loess. Initially, flood plains were the principal sources of eolian sediment, but during the Holocene, dunes formed from older eolian sand and alluvium on uplands. Since latest Pleistocene...
Petrology of Submarine Lavas from Kilauea's Puna Ridge, Hawaii
D. A. Clague, James G. Moore, J.E. Dixon, W.B. Friesen
1995, Journal of Petrology (36) 299-349
We have studied 30 quenched tholeiitic lava flows recovered by 20 dredge hauls and one submersible dive along Puna Ridge, the submarine part of the East Rift Zone of Kilauea Volcano, Hawaii Glass grains from numerous additional flows were recovered in turbidite sands cored in the Hawaiian Trough. These quenched...
The Pennsylvanian Fire Clay tonstein of the Appalachian basin—Its distribution, biostratigraphy, and mineralogy: Discussion and reply
William Outerbridge, C. L. Rice, Harvey E. Belkin, T.W. Henry, Michael J. Kunk
1995, GSA Bulletin (108) 120-125
No abstract available....
Composition of biotite phenocrysts in Ordovician tephras casts doubt on the proposed trans-Atlantic correlation of the Millbrig K-bentonite (United States) and the Kinnekulle K-bentonite (Sweden)
John T. Haynes, W.G. Melson, Michael J. Kunk
1995, Geology (23) 847-850
Biotite phenocryst compositions in three thick, widespread Ordovician K-bentonites, the Deicke and Millbrig from Big Ridge, Alabama, and the Kinnekulle from Mossen, Västergötland, Sweden, fall into three distinct groups, and so the proposed intercontinental correlation of the Millbrig and the Kinnekulle is suspect. Because the biotites are nearly pristine compositionally,...
Mudflow generated by retrogressive slope failure, Santa Barbara Basin, California continental borderland
Brian D. Edwards, Homa J. Lee, Michael E. Field
1995, Journal of Sedimentary Research (A65) 57-68
The morphology and internal geometry of a mudflow deposit on the mainland slope of the Santa Barbara Basin are defined using high-resolution seismic-reflection data in combination with core samples. Sediment failure occurred on a 4 degrees slope in the uppermost part of late Quaternary well-bedded slope deposits. The failure zone...
Age of the Cenomanian-Turonian boundary in the Western Interior of the United States
B. J. Kowallis, Eric H. Christiansen, Alan L. Deino, Michael J. Kunk, L. Heaman
1995, Cretaceous Research (16) 109-129
High precision 40Ar/39Ar laser-microprobe ages of individual sanidines,40Ar/39Ar plateau age spectra on bulk sanidine concentrates, U-Pb zircon ages, and zircon and apatite fission-track ages from three bentonites bracketing the Cenomanian-Turonian boundary in the Western Interior of the United States suggest an age for the boundary of 93.1 ± 0.3 (2σ. The...
Metamorphic and structural history of continental crust at a Mesozoic collisional margin, the Ruby terrane, central Alaska
S. M. Roeske, Cynthia Dusel-Bacon, John N. Aleinikoff, L.W. Snee, Marvin A. Lanphere
1995, Journal of Metamorphic Geology (13) 25-40
The Ruby terrane is an elongate fragment of continental crustal rocks that is structurally overlain by thrust slices of oceanic crust. Our results from the Kokrines Hills, in the south‐central part of the Ruby terrane, demonstrate that the low‐angle schistose fabric formed under high‐P/low‐T conditions, at peak conditions of 10.8‐13.2 kbar...
Middle Tertiary extension recorded by lacustrine fan-delta deposits, Plush Ranch Basin, western Transverse Ranges, California
Ronald B. Cole, Richard G. Stanley
1995, Journal of Sedimentary Research (65) 455-468
The Plush Ranch Formation (upper Oligocene and lower Miocene) consists of more than 1800 m of nonmarine sedimentary and volcanic rocks that record the history of an extensional basin referred to here as the Plush Ranch basin. Distinctive depositional facies, provenance, and sediment transport directions along each basin margin suggest...
Plutonism at the interior margin of the Jurassic magmatic arc, Mojave Desert, California
Miquette E. Gerber, Calvin F. Miller, Joseph L. Wooden
David M. Miller, Cathy Busby, editor(s)
1995, Book chapter, Jurassic magmatism and tectonics of the North American cordillera
The inland edge of the Jurassic magmatic belt passes through the eastern Mojave Desert, where it was emplaced in ancient continental crust. Three intrusive units exposed there—the Ship and Clipper Mountains plutons and a dike swarm in the Old Woman and Piute Mountains and Kilbeck Hills—are broadly similar to each...
Jurassic tectonics of northeastern Nevada and northwestern Utah from the perspective of barometric studies
David M. Miller, Thomas D. Hoisch
Cathy Busby, editor(s)
1995, Book chapter, Jurassic magmatism and tectonics of the North American cordillera
Jurassic tectonism in the northeastern Great Basin produced varied structures, many closely associated with widespread magmatism at ca. 155–165 Ma and with local metamorphism. Many of the plutons are of suitable mineralogy for Al-in-hornblende barometry, providing the potential for depth data. We have studied conditions of metamorphism in the Pilot...
Preliminary development of the LBL/USGS three-dimensional site-scale model of Yucca Mountain, Nevada
1995, Book
A three-dimensional model of moisture flow within the unsaturated zone at Yucca Mountain is being developed at Lawrence Berkeley Laboratory (LBL) in cooperation with the U.S. Geological Survey (USGS). This site-scale model covers and area of about 34 km2 and is bounded by major faults to the north, east and...
Timing of emplacement of the Haypress Creek and Emigrant Gap plutons: Implications for the timing and controls of Jurassic orogenesis, northern Sierra Nevada, California
Gary H. Girty, Richard E. Hanson, Melissa S. Girty, Richard A. Schweickert, David S. Harwood, Aaron S. Yoshinobu, Kevin A. Bryan, June E. Skinner, Chris A. Hill
David M. Miller, Cathy Busby, editor(s)
1995, Book chapter, Jurassic magmatism and tectonics of the North American cordillera
Pre-Cretaceous rocks in the northern Sierra Nevada are subdivided from west to east into the Smartville, central, Feather River peridotite, and eastern belts. Cretaceous and younger sedimentary rocks form the western boundary of the Smartville belt, but various reverse-fault segments of the Foothills fault system separate the other belts. The...
Evolution of tholeiitic diabase sheet systems in the eastern United States: examples from the Culpeper Basin, Virginia-Maryland, and the Gettysburg Basin, Pennsylvania
Laurel G. Woodruff, A.J. Froelich, Harvey E. Belkin, D. Gottfried
1995, Journal of Volcanology and Geothermal Research (64) 143-169
High-TiO2, quartz-normative (HTQ) tholeiite sheets of Early Jurassic age have intruded mainly Late Triassic sedimentary rocks in several early Mesozoic basins in the eastern US. Field observations, petrographic study, geochemical analyses and stable isotope data from three HTQ sheet systems were used to develop a general model of magmatic differentiation...
Geologic and societal factors affecting the international oceanic transport of aggregate
W. H. Langer
1995, Nonrenewable Resources (4) 303-309
Crushed stone and sand and gravel are the two main sources of natural aggregate, and together comprise approximately half the volume and tonnage of mined material in the United States. Natural aggregate is a bulky, heavy material without special or unique properties, and it is commonly used near its source...
Relations between atmospheric circulation and mass balance of South Cascade Glacier, Washington, USA
G. J. McCabe Jr., A. G. Fountain
1995, Arctic and Alpine Research (27) 226-233
The yearly net mass balance of South Cascade Glacier, Washington, has decreased since the mid-1970s. Results show that the decrease is primarily caused by a significant decrease in the winter mass balance. The decrease in winter mass balance is caused, in part, by changes in winter mean atmospheric circulation that...
Basement and cover-rock deformation during Laramide contraction in the northern Madison Range (Montana) and its influence on Cenozoic basin formation
Karl S. Kellogg, C. J. Schmidt, S. W. Young
1995, American Association of Petroleum Geologists Bulletin (79) 1117-1137
Two major Laramide fault systems converge in the northwestern Madison Range: the northwest-striking, southwest-vergent Spanish Peaks reverse fault and the north-striking, east-vergent Hilgard thrust system. Analysis of foliation attitudes in basement gneiss north and south of the Spanish Peaks fault indicates that the basement in thrusted blocks of the Hilgard...
High-pressure amphibolite facies dynamic metamorphism and the Mesozoic tectonic evolution of an ancient continental margin, east- central Alaska
Cynthia Dusel-Bacon, V. L. Hansen, J.A. Scala
1995, Journal of Metamorphic Geology (13) 9-24
Ductilely deformed amphibolite facies tectonites comprise two adjacent terranes in east-central Alaska: the northern, structurally higher Taylor Mountain terrane and the southern, structurally lower Lake George subterrane of the Yukon-Tanana terrane. The pressure, temperature, kinematic and age data are interpreted to indicate that the metamorphism of the Taylor Mountain terrane...
Superposed local and regional paleostresses: fault-slip analysis of Neogene extensional faulting near coeval caldera complexes, Yucca Flat, Nevada
S.A. Minor
1995, Journal of Geophysical Research (100) 10507-10528
Numerous reduced stress tensors are computed by multiple inversions of 906 temporally and spatially partitioned fault-slip data from the Yucca Flat region in the southwest Nevada volcanic field to constrain the Neogene paleostress and faulting history and to investigate how the regional tectonic stress field...
Geologic framework of a transect of the central Brooks Range: Regional relations and an alternative to the Endicott Mountains allochthon
John S. Kelley, W. P. Brosge
1995, American Association of Petroleum Geologists Bulletin (79) 1087-1115
This paper evaluates the geologic framework and tectonic development of the central Brooks Range based on a transect through the range and Arctic foothills. A geologic cross section constructed through the transect is confirmed by comparing the retrodeformed section with the regional distribution of lithofacies in the central Brooks Range....
Relations between winter atmospheric circulation and annual streamflow in the western United States
G. J. McCabe Jr.
1995, Climate Research (5) 139-148
Winter mean 700 millibar (700 mb) height anomalies, representing the average atmospheric circulation during the snow season, were compared with annual streamflow measured at 140 stream gauges in the western United States. Correlation analysis was used to identify relations between winter mean atmospheric circulation and annual streamflow, and to quantify...
Tectonic setting of the Portland-Vancouver area, Oregon and Washington: Constraints from low-altitude aeromagnetic data
R.J. Blakely, R.E. Wells, T.S. Yelin, I. P. Madin, M.H. Beeson
1995, Geological Society of America Bulletin (107) 1051-1062
Seismic activity in the Portland-Vancouver metropolitan area may be associated with various mapped faults that locally offset volcanic basement of Eocene age and younger. This volcanic basement is concealed in most places by young deposits, vegetation, and urban development. The U.S. Geological Survey...
Giant blocks in the South Kona landslide, Hawaii
J.G. Moore, W.B. Bryan, M.H. Beeson, W. R. Normark
1995, Geology (23) 125-128
A large field of blocky sea-floor hills, up to 10 km long and 500 m high, are gigantic slide blocks derived from the west flank of Mauna Loa volcano on the island of Hawaii. These megablocks are embedded in the toe of the...
Sediment resuspension mechanisms in Old Tampa Bay, Florida
D. H. Schoellhamer
1995, Estuarine, Coastal and Shelf Science (40) 603-620
The mechanisms that resuspend bottom sediments in Old Tampa Bay, a shallow, microtidal, subtropical estuary in west-central Florida, were determined by analysing data collected during several periods from 1988 to 1990. Hydrodynamic and suspended-solids concentration data were collected at a relatively deep (4 m) site where a permanent platform was built...
