Minimum size limits for yellow perch (Perca flavescens) in western Lake Erie
Wilbur L. Hartman, Stephen J. Nepszy, Russell L. Scholl
1980, Technical Report 39
During the 1960's yellow perch (Perca flavescens) of Lake Erie supported a commercial fishery that produced an average annual catch of 23 million pounds, as well as a modest sport fishery. Since 1969, the resource has seriously deteriorated. Commercial landings amounted to only 6 million pounds in 1976, and included...
Rare earth element distribution in some hydrothermal minerals: Evidence for crystallographic control
J. W. Morgan, G.A. Wandless
1980, Geochimica et Cosmochimica Acta (44) 973-980
Rare earth element (REE) abundances were measured by neutron activation analysis in anhydrite (CaSO4), barite (BaSO4), siderite (FeCO3) and galena (PbS). A simple crystal-chemical model qualitatively describes the relative affinities for REE substitution in anhydrite, barite, and siderite. When normalized to ‘crustal’ abundances (as an approximation to the hydrothermal fluid...
Implications of regional gravity for state of stress in the earth's crust and upper mantle
M. McNutt
1980, Journal of Geophysical Research Solid Earth (85) 6377-6396
Topography is maintained by stress differences within the earth. Depending on the distribution of the stress we classify the support as either local or regional compensation. In general, the stresses implied in a regional compensation scheme are an order of magnitude larger than those corresponding to local isostasy. Gravity anomalies,...
Speculations on processes responsible for mesoscale current lineations on the continental shelf, southern California
Herman A. Karl
1980, Marine Geology (34) M9-M18
A side-scan sonar survey of San Pedro shelf, California, reveals areas of mesoscale current lineations oriented approximately north-northeast in water depths of 20-25 m. Widths of sand ribbons range from 40 to 120 m and intervening erosional furrows, from 15 to 50 m. A conceptual model shows that the scale...
Mixing models and ionic geothermometers applied to warm (up to 60°C) springs: Jordan Rift Valley, Israel
E. Mazor, D. Levitte, A.H. Truesdell, J. Healy, A. Nissenbaum
1980, Journal of Hydrology (45) 1-19
Mixing models and evaluation of SiO2 contents of warm-water manifestations in the Jordan—Dead Sea Rift Valley indicate that these waters are fed by aquifers with estimated temperatures of up to 68°C. These calculations and Na/K ratios, concentrations of Na, K and Ca, concentrations of atmospheric Ne, Ar, Kr and Xe;...
Nd-isotopes in selected mantle-derived rocks and minerals and their implications for mantle evolution
A. R. Basu, M. Tatsumoto
1980, Contributions to Mineralogy and Petrology (75) 43-54
The Sm-Nd systematics in a variety of mantle-derived samples including kimberlites, alnoite, carbonatite, pyroxene and amphibole inclusions in alkali basalts and xenolithic eclogites, granulites and a pyroxene megacryst in kimberlites are reported. The additional data on kimberlites strengthen our earlier conclusion that kimberlites are derived from a relatively undifferentiated chondritic...
Crystallization history of Kilauea Iki lava lake as seen in drill core recovered in 1967-1979
Rosalind Tuthill Helz
1980, Bulletin Volcanologique (43) 675-701
Kilauea Iki lava lake formed during the 1959 summit eruption, one of the most picritic eruptions of Kilauea Volcano in the twentieth century. Since 1959 the 110 to 122 m thick lake has cooled slowly, developing steadily thickening upper and lower crusts, with a lens of more molten lava in...
Nearshore current pattern off south Texas: an interpretation from aerial photographs.
R. E. Hunter, G. W. Hill
1980, Remote Sensing of Environment (10) 115-134
Current patterns in a 4-km-wide zone along the south Texas coast were interpreted from patterns of water turbidity visible in aerial photographs taken during a winter day of moderate northerly winds. Features of the turbidity pattern remained recognizable on photographs taken 25 min apart. Currents measured from the movements of...
A three-dimensional model to predict future oil discoveries in spatially connected multiple plays
J.H. Schuenemeyer, L.J. Drew, W.J. Bawiec
1980, Journal of the International Association for Mathematical Geology (12) 459-472
A discovery-process model that had been devised previously to estimate the size distribution of oil and gas fields remaining to be discovered in a single producing horizon was adapted to a basin containing spatially connected multiple plays and producing horizons. This model used the concept of the area of influence...
Small impact craters in the lunar regolith - Their morphologies, relative ages, and rates of formation
H. J. Moore, J. M. Boyce, D.A. Hahn
1980, The Moon and the Planets (23) 231-252
Apparently, there are two types of size-frequency distributions of small lunar craters (???1-100 m across): (1) crater production distributions for which the cumulative frequency of craters is an inverse function of diameter to power near 2.8, and (2) steady-state distributions for which the cumulative frequency of craters is inversely proportional...
Stable isotope and fluid inclusion studies of carbonate deposits from the Tolfa Mountains mining district (Latium, central Italy)
U. Masi, V. Ferrini, J. R. O’Neil, J. N. Batchelder
1980, Mineralium Deposita (15) 351-359
Carbon and oxygen isotope analyses were made of representative samples of calcite and quartz from the carbonate deposits in the Tolfa Mountains mining district. Measurements were also made of hydrogen isotope compositions, filling temperatures and salinities of fluid inclusions in these minerals. There are three stages of mineralization at Tolfa....
Mid- Tertiary climate of southeastern United States, the sporomorph evidence
N. O. Frederiksen
1980, Journal of Paleontology (54) 728-739
Climatic affinities of modern genera represented by late Eocene sporomorphs suggest that the climate of that time in southeastern United States was winter-dry tropical close to the Gulf of Mexico and marginal humid subtropical on the upper Coastal Plain. Lack of change of the sporomorph assemblages suggests that the climate...
Transition of basaltic lava from pahoehoe to aa, Kilauea Volcano, Hawaii: Field observations and key factors
Donald W. Peterson, Robert I. Tilling
1980, Journal of Volcanology and Geothermal Research (7) 271-293
Nearly all Hawaiian basaltic lava erupts as pahoehoe, and some changes to aa during flowage and cooling; factors governing the transition involve certain critical relations between viscosity and rate of shear strain. If the lava slows, cools, and stops in direct response to concomitant increase in viscosity before these critical...
Depositional environments of some Pleistocene coastal terrace deposits, southwestern Oregon - case history of progradational beach and dune sequence.
R. E. Hunter
1980, Sedimentary Geology (27) 241-262
These deposits comprise a basal gravelly unit and 3 overlying sandy units, each with mud beds, a paleosol, or the modern soil in its uppermost part. The gravelly unit is interpreted as a progradational deposit. The main parts of the sandy units are made up of 1) a crossbedded sand...
Modern and ancient submarine fans: Reply
William R. Normark
1980, American Association of Petroleum Geologists Bulletin (64) 1108-1112
No abstract available....
Tertiary δ18O record and glacio-eustatic sea-level fluctuations
R.K. Matthews, R.Z. Poore
1980, Geology (8) 501-504
Previous interpretation of the Tertiary δ18O record of plaiiktic and benthic foraminifers has emphasized comparison to the modern ocean, assumed an ice-free world prior to middle Miocene time, and thereby calculated surprisingly cool temperatures for the tropical sea surface. We propose an alternative...
Faulting caused by groundwater level declines, San Joaquin Valley, California
Thomas L. Holzer
1980, Water Resources Research (16) 1065-1070
Approximately 230 mm of aseismic vertical offset of the land surface across the Pond-Poso Creek fault in the San Joaquin Valley, California, probably is related to groundwater withdrawal for crop irrigation. The scarp is approximately 3.4 km long and occurs in an area where the land subsided more than 1.5...
A model to forecast short-term snowmelt runoff using synoptic observations of streamflow, temperature, and precipitation
Wendell V. Tangborn
1980, Water Resources Research (16) 778-786
Snowmelt runoff is forecast with a statistical model that utilizes daily values of stream discharge, gaged precipitation, and maximum and minimum observations of air temperature. Synoptic observations of these variables are made at existing low- and medium-altitude weather stations, thus eliminating the difficulties and expense of new, high-altitude installations. Four...
Modern and ancient submarine fans: Discussion of papers by Walker and Normark.
Tor H. Nilsen
1980, American Association of Petroleum Geologists Bulletin (64) 1094-1101
No abstract available....
Rate of mercury loss from contaminated estuarine sediments
Michael H. Bothner, R.A. Jahnke, M. L. Peterson, R. Carpenter
1980, Geochimica et Cosmochimica Acta (44) 273-285
The concentration of mercury in contaminated estuarine sediments of Bellingham Bay, Washington was found to decrease with a half-time of about 1.3 yr after the primary anthropogenic source of mercury was removed. In situ measurements of the mercury flux from sediments, in both dissolved and volatile forms, could not account...
Computational methods for inverse problems in geophysics: Inversion of travel time observations
V. Pereyra, H.B. Keller, W.H.K. Lee
1980, Physics of the Earth and Planetary Interiors (21) 120-125
General ways of solving various inverse problems are studied for given travel time observations between sources and receivers. These problems are separated into three components: (a) the representation of the unknown quantities appearing in the model; (b) the nonlinear least-squares problem; (c) the direct, two-point ray-tracing problem used to compute...
Accuracy of an estuarine hydrodynamic model using smooth elements
Roy A. Walters, Ralph T. Cheng
1980, Water Resources Research (16) 187-195
A finite element model which uses triangular, isoparametric elements with quadratic basis functions for the two velocity components and linear basis functions for water surface elevation is used in the computation of shallow water wave motions. Specifically addressed are two common uncertainties in this class of two-dimensional hydrodynamic models: the...
Toxicity of five forest insecticides to cutthroat trout and two species of aquatic invertebrates
D. F. Woodward, W.L. Mauck
1980, Bulletin of Environmental Contamination and Toxicology (25) 846-854
The Northern Rocky Mountain region has had scattered infestation of the western spruce budworm Christoneura occidentalis since the early 1900's (U.S. DEPARTMENT OF AGRICULTURE (USDA) 1976b). On the basis of aerial surveys in 1975, TUNNOCK et al. (1976), estimated that budworm defoliation occurred on 2,278,804 acres of six National Forests...
The behavior of 14C and 13C in estuarine water: Effects of In situ CO2 production and atmospheric exchange
Elliott C. Spiker
1980, Radiocarbon (22) 647-654
The effects of nonconservative sources (inputs) and sinks (outputs) of carbon are indicated by the behavior of Δ14C and δ13C of the total dissolved inorganic carbon (ΣCO2) in San Francisco Bay and Chesapeake Bay. Isotopic distributions and model calculations indicate that in North San Francisco Bay the net CO2 flux to...
Lake trout (Salvelinus namaycush) and sea lamprey (Petromyzon marinus) populations in Lake Michigan, 1971-78
LaRue Wells
1980, Canadian Journal of Fisheries and Aquatic Sciences (37) 2047-2051
Lake trout (Salvelinus namaycush) was exterminated in Lake Michigan by the mid-1950s as a result of the combined effects of an intensive fishery and predation by the sea lamprey (Petromyzon marinus). The widespread application of lampricide in tributary streams had greatly reduced the abundance of lampreys by the early 1960s,...
