A comparison of coupled freshwater-saltwater sharp-interface and convective-dispersive models of saltwater intrusion in a layered aquifer system
Mary C. Hill
1988, Developments in Water Science 211-216
Simulated results of the coupled freshwater-saltwater sharp interface and convective-dispersive numerical models are compared by using steady-state cross-sectional simulations. The results indicate that in some aquifers the calculated sharp interface is located further landward than would be expected....
Generalized potentiometric surface of shallow aquifers in southern Mississippi, 1982
E. H. Boswell, J. K. Arthur
1988, Water-Resources Investigations Report 87-4257
Age and height distribution of holocene transgressive deposits in eastern North Island, New Zealand
Y. Ota, K.R. Berryman, A.G. Hull, T. Miyauchi, N. Iso
1988, Palaeogeography, Palaeoclimatology, Palaeoecology (68) 135-151
Holocene transgressive deposits are frequently exposed near the present-day coastline of the study area along eastern North Island, New Zealand. They occur in sites of former estuaries that were filled during the postglacial rise in sea level. We present one hundred radiocarbon dates of Holocene transgressive deposits from the study...
Wind directions predicted from global circulation models and wind directions determined from eolian sandstones of the western United States - A comparison
Judith T. Parrish, F. Peterson
1988, Sedimentary Geology (56) 261-282
Wind directions for Middle Pennsylvanian through Jurassic time are predicted from global circulation models for the western United States. These predictions are compared with paleowind directions interpreted from eolian sandstones of Middle Pennsylvanian through Jurassic age. Predicted regional wind directions correspond with at least three-quarters of the paleowind data from...
Pennsylvanian to Jurassic eolian transportation systems in the western United States
F. Peterson
1988, Sedimentary Geology (56) 207-260
The direction of sediment transport in eolian sandstones of Pennsylvanian to Jurassic age was interpreted from crossbedding resultants (vector means) obtained from studies of eolian rocks in the western U.S., supplemented by data from the few eolian units of eastern North America. These were compiled from the published or...
Synthesis of late Paleozoic and Mesozoic eolian deposits of the Western Interior of the United States
R.C. Blakey, F. Peterson, G. Kocurek
1988, Sedimentary Geology (56) 3-125
Late Paleozoic and Mesozoic eolian deposits include rock units that were deposited in ergs (eolian sand seas), erg margins and dune fields. They form an important part of Middle Pennsylvanian through Upper Jurassic sedimentary rocks across the Western Interior of the United States. These sedimentary rock units comprise approximately three...
Suspended sediment transport under estuarine tidal channel conditions
R.W. Sternberg, K. Kranck, D.A. Cacchione, D.E. Drake
1988, Sedimentary Geology (57) 257-272
A modified version of the GEOPROBE tripod has been used to monitor flow conditions and suspended sediment distribution in the bottom boundary layer of a tidal channel within San Francisco Bay, California. Measurements were made every 15 minutes over three successive tidal cycles. They included mean velocity profiles from four...
The record of major quaternary sea-level changes in a large coastal plain estuary, Chesapeake Bay, Eastern United States
Steven M. Colman, R. B. Mixon
1988, Palaeogeography, Palaeoclimatology, Palaeoecology (68) 99-116
Seismic-reflection surveys of the Chesapeake Bay, combined with geologic mapping and analysis of boreholes on the Delmarva Peninsula, provide evidence of at least three generations of the Susquehanna River system and three generations of the Chesapeake Bay. The evidence for ancient courses of the Susquehanna River is preserved as three...
Aftershocks of the western Argentina (Caucete) earthquake of 23 November 1977: Some tectonic implications
C.J. Langer, G. A. Bollinger
1988, Tectonophysics (148) 131-146
An aftershock survey, using a network of eight portable and two permanent seismographs, was conducted for the western Argentina (Caucete) earthquake (MS 7.3) of November 23, 1977. Monitoring began December 6, almost 2 weeks after the main shock and continued for 11 days. The data set includes 185 aftershock hypocenters that...
Lacustrine varve formation through time
R.Y. Anderson, W.E. Dean
1988, Palaeogeography, Palaeoclimatology, Palaeoecology (62) 215-235
Studies using sediment traps in lakes reveal that the seasonal flux of sediment regulates both the composition and timing of deposition of materials that reach the bottoms of lakes. If the bottom waters of a lake are partly or totally anoxic, the seasonally deposited materials are preserved as annual groupings...
Seismic anisotropy in mylonites: An example from the Mannin Thrust Zone, southwest Connemara, Ireland
P.N. Chroston, M.D. Max
1988, Tectonophysics (148) 29-39
Mylonites associated with the Mannin Thrust zone of southwesternmost Connemara formed when the high-grade metamorphic rocks typical of most of the Connemara massif were thrust to the southeast over low metamorphic grade (low greenschist facies?) acid volcanics and volcaniclastic sediments, while being metamorphosed in the epidote-amphibolite facies. Triaxial and biaxial...
Fossil diatoms and neogene paleolimnology
Bradbury J. Platt
1988, Palaeogeography, Palaeoclimatology, Palaeoecology (62) 299-316
Diatoms have played an important role in the development of Neogene continental biostratigraphy and paleolimnology since the mid-19th Century. The history of progress in Quaternary diatom biostratigraphy has developed as a result of improved coring techniques that enable sampling sediments beneath existing lakes coupled with improved chronological control (including radiometric...
Paleolimnology of Lake Tubutulik, an iron-meromictic Eocene Lake, eastern Seward Peninsula, Alaska
Kendall A. Dickinson
1988, Sedimentary Geology (54) 303-320
Sideritic lacustrine mudstone was found in drill core from a uranium deposit in the Death Valley area in the eastern part of the Seward Peninsula, Alaska. The precursor sediments for this rock were deposited in an unusual “iron-meromictic” Eocene lake, herein named Lake Tubutulik, which occupied part of the Boulder...
A proposed mechanism for the formation of spherical vivianite crystal aggregates in sediments
J.L. Zelibor Jr., F. E. Senftle, J.L. Reinhardt
1988, Sedimentary Geology (59) 125-142
Vivianite [Fe3(PO4)2·8H2O] is often found in the form of nodules composed of spherical aggregates of crystals. Crystallization of vivianite in agar gels of various concentrations yield crystal aggregates (nodules) that have spherical morphology and a bimodal size distribution. The aggregates were formed under both biotic and abiotic conditions. When special...
Early diagenesis of eolian dune and interdune sands at White Sands, New Mexico
Christopher J. Schenk, S.G. Fryberger
1988, Sedimentary Geology (55) 109-120
The degree of early diagenesis in eolian dune and interdune sands at White Sands, New Mexico, is largely a function of the relationship between sand location and the water table. Most active and vegetation-stabilized dune sands are in the vadose zone, whereas interdune sands are in the capillary fringe and...
Daily cycles in coastal dunes
R. E. Hunter, Bruce M. Richmond
1988, Sedimentary Geology (55) 43-67
Daily cycles of summer sea breezes produce distinctive cyclic foreset deposits in dune sands of the Texas and Oregon coasts. In both areas the winds are strong enough to transport sand only during part of the day, reach a peak during the afternoon, and vary little in direction during the...
Pin stripe lamination: A distinctive feature of modern and ancient eolian sediments
S.G. Fryberger, Christopher J. Schenk
1988, Sedimentary Geology (55) 1-15
Pin stripe laminations are a distinctive feature of modern and ancient eolian sediments. In sets of eolian ripple (or translatent) strata they represent deposition of silt and very fine sand in the troughs of the advancing wind ripples. In sets of avalanche strata they probably result from the downward settling...
An improved dark-object subtraction technique for atmospheric scattering correction of multispectral data
Pat S. Chavez Jr.
1988, Remote Sensing of Environment (24) 459-479
Digital analysis of remotely sensed data has become an important component of many earth-science studies. These data are often processed through a set of preprocessing or “clean-up” routines that includes a correction for atmospheric scattering, often called haze. Various methods to correct or remove the additive haze component have been...
Use of airborne imaging spectrometer data to map minerals associated with hydrothermally altered rocks in the northern Grapevine Mountains, Nevada, and California
F.A. Kruse
1988, Remote Sensing of Environment (24) 31-51
Three flightlines of Airborne Imaging Spectrometer (AIS) data, acquired over the northern Grapevine Mountains, Nevada, and California, were used to map minerals associated with hydrothermally altered rocks. The data were processed to remove vertical striping, normalized using an equal area normalization, and reduced to reflectance relative to an average spectrum...
Refined Proterozoic evolution of the Gawler Craton, South Australia, through U-Pb zircon geochronology
C.M. Fanning, R.B. Flint, A.J. Parker, K.R. Ludwig, A.H. Blissett
1988, Precambrian Research (40-41) 363-386
Through the application of both conventional U-Pb zircon analyses and small-sample U-Pb isotopic analyses, the nature and timing of tectonic events leading to the formation of the Gawler Craton have been defined more precisely. Constraints on deposition of Early Proterozoic iron formation-bearing sediments have been narrowed down to the period...
Precambrian ophiolites of Arabia: Geologic settings, U Pb geochronology, Pb-isotope characteristics, and implications for continental accretion
J.S. Pallister, J. S. Stacey, L. B. Fischer, W. R. Premo
1988, Precambrian Research (38) 1-54
Disrupted ophiolites occur in linear belts up to 900 km long between microplates that collided during the late Proterozoic to form the Arabian Shield. UPb zircon ages and Pb-isotope data from these ophiolitic rocks help constrain the history of accretion of the Arabian Shield and thereby contribute to the definition...
Biological measurements and related chemical features in Soviet and United States regions of the Bering Sea
T.E. Whitledge, R.R. Bidigare, Stephan O. Zeeman, R. N. Sambrotto, Pasquale F. Roscigno, Paul R. Jensen, James M. Brooks, Charles Trees, Denise M. Veldt
1988, Continental Shelf Research (8) 1299-1319
The U.S. results of a joint U.S.-U.S.S.R. expedition to the Bering Sea in 1984 investigated the chemical and biological interactions in the south, east, north and west regions. The nutrients, phytoplankton biomass and primary productivity were enhanced near the ends of a north-south transect of stations. The southern end of...
Lognormal kriging for the assessment of reliability in groundwater quality control observation networks
L. Candela, Ricardo A. Olea, E. Custodio
1988, Journal of Hydrology (103) 67-84
Groundwater quality observation networks are examples of discontinuous sampling on variables presenting spatial continuity and highly skewed frequency distributions. Anywhere in the aquifer, lognormal kriging provides estimates of the variable being sampled and a standard error of the estimate. The average and the maximum standard error within the network can...
Pumping tests in nonuniform aquifers - The radially symmetric case
J.J. Butler Jr.
1988, Journal of Hydrology (101) 15-30
Traditionally, pumping-test-analysis methodology has been limited to applications involving aquifers whose properties are assumed uniform in space. This work attempts to assess the applicability of analytical methodology to a broader class of units with spatially varying properties. An examination of flow behavior in a simple configuration consisting of pumping from...
Experimental studies in stream-aquifer interaction along the Arkansas River in Central Kansas - Field testing and analysis
M. Sophocleous, M.A. Townsend, L.D. Vogler, T.J. McClain, E.T. Marks, G.R. Coble
1988, Journal of Hydrology (98) 249-273
During the last several years, streamflows of a number of Kansas streams have been reduced as a result of groundwater declines. In order to better understand and quantify stream-aquifer interrelationships, an eight-day comprehensive stream-aquifer pumping test, followed by recovery monitoring, was conducted along the Arkansas River near Great Bend, Kansas....
