Idealized debris flow in flume with bed driven by a conveyor belt
Chi-Hai Ling, Cheng-lung Chen
1989, Conference Paper
The generalized viscoplastic fluid (GVF) model is used to derive the theoretical expressions of two-dimensional velocities and surface profile for debris flow established in a flume with bed driven by a conveyor belt. The rheological parameters of the GVF model are evaluated through the comparison of theoretical results with measured...
An attempt to obtain a detailed declination chart from the United States magnetic anomaly map
L.R. Alldredge
1989, Journal of Geomagnetism & Geoelectricity (41) 549-563
Modern declination charts of the United States show almost no details. Greater detail may be of value to surveyors trying to follow old land deed descriptions, or to pilots of small planes or small pleasure boats operating in inland waterways. It would be extremely expensive to make adequate...
Style of extensional tectonism during rifting, Red Sea and Gulf of Aden
R. G. Bohannon
1989, Journal of African Earth Sciences (8) 589-602
Models describing the development of the Red Sea and the Gulf of Aden, prior to the present periods of sea-floor spreading, include those that use block faulting on steep normal faults, uniform diffuse shear in continental crust, simple shear on large detachment faults that cut the entire lithosphere, combinations involving...
The competition between thermal contraction and differentiation in the stress history of the Moon
Randolph L. Kirk, David J. Stevenson
1989, Journal of Geophysical Research B: Solid Earth (94) 12133-12144
The scarcity of both extension and compression features on the Moon strongly constrains the history of the lunar radius—to variations of less than ±1 km over the past 3.8 Gyr. This limit has traditionally been interpreted as requiring a delicate balance between thermal contraction of the near‐surface and expansion of...
Petrology of the zoned calcalkaline magma chamber of Mount Mazama, Crater Lake, Oregon
T. H. Druitt, C. R. Bacon
1989, Contributions to Mineralogy and Petrology (101) 245-259
Evolution of the magma chamber at Mount Mazama involved repeated recharge by two types of andesite (high-Sr and low-Sr), crystal fractionation, crystal accumulation, assimilation, and magma mixing (Bacon and Druitt 1988). This paper addresses the modal compositions, textures, mineral chemistry and magmatic temperatures of (i) products of the 6845±50 BP...
Hydrologic effects of climate change in the Delaware River basin
Gregory J. McCabe, Mark A. Ayers
1989, Water Resources Bulletin (25) 1231-1242
The Thornthwaite water balance and combinations of temperature and precipitation changes representing climate change were used to estimate changes in seasonal soil-moisture and runoff in the Delaware River basin. Winter warming may cause a greater proportion of precipitation in the northern part of the basin to fall as rain, which...
Petrology and age of alkalic lava from the Ratak Chain of the Marshall Islands
A. S. Davis, M. S. Pringle, L.-B.G. Pickthorn, D.A. Clague, W. C. Schwab
1989, Journal of Geophysical Research Solid Earth (94) 5757-5774
Volcanic rock dredged from the flanks of four volcanic edifices in the Ratak chain of the Marshall Islands consist of alkalic lava that erupted above sea level or in shallow water. Compositions of recovered samples are predominantly differentiated alkalic basalt and hawaiite but include strongly alkalic melilitite. Whole rock 40Ar/39Ar total...
Origin of Sr, Nd and Pb isotopic systematics in high-Sr basalts from central Arizona
J.H. Wittke, D. Smith, J. L. Wooden
1989, Contributions to Mineralogy and Petrology (101) 57-68
Alkalic and tholeiitic basalts were erupted in the central Arizona Transition Zone during Miocene-Pliocene time before and after regional faulting. The alkalic lava types differ from the subalkaline lavas in Sr, Nd and Pb isotopic ratios and trace element ratios and, despite close temporal and spatial relationships, the two types...
Distillation irrigation: A low-energy process for coupling water purification and drip irrigation
Jim Constantz
1989, Agricultural Water Management (15) 253-264
A method is proposed for combining solar distillation and drip irrigation to simultaneously desalinize water and apply this water to row crops. In this paper, the basic method is illustrated by a simple device constructed primarily of sheets of plastic, which uses solar energy to distill impaired water and apply...
Oligocene caldera complex and calc-alkaline tuffs and lavas of the Indian Peak volcanic field, Nevada and Utah
M. G. Best, E. H. Christiansen, H. R. Blank Jr.
1989, Geological Society of America Bulletin (101) 1076-1090
The Indian Peak volcanic field is representative of the more than 50,000 km3 of ash-flow tuff and tens of calderas in the Great Basin that formed during the Oligocene-early Miocene "ignimbrite flareup" in southwestern North America. The field formed about 32 to 27 Ma in the southeastern Great Basin and consists...
Manganese oxidation model for rivers
Glen W. Hess, Byung R. Kim, Philip J.W. Roberts
1989, Water Resources Bulletin (25) 359-365
The presence of manganese in natural waters (>0.05 mg/L) degrades water-supply quality. A model was devised to predict the variation of manganese concentrations in river water released from an impoundment with the distance downstream. The model is one-dimensional and was calibrated using dissolved oxygen, biochemical oxygen demand, pH, manganese, and...
Assessment of the U-Th-Pb system in two Archean metabasalts: Deciphering the complex histories of sulphides and silicates using acid leaching methods
P. E. Smith, R.M. Farquhar, M. Tatsumoto
1989, Geochimica et Cosmochimica Acta (53) 2051-2068
A U-Th-Pb study of Archean metabasalts from two greenstone belts in the eastern Wawa Subprovince of the Canadian shield indicated variable disturbances had occurred in both whole rock systems. Changes in the Pb content appear to predominate over loss of parent elements, and meaningful Pb isochron ages could not be...
The role of catastrophic geomorphic events in central Appalachian landscape evolution
R. B. Jacobson, A.J. Miller, J. A. Smith
1989, Geomorphology (2) 257-284
Catastrophic geomorphic events are taken as those that are large, sudden, and rare on human timescales. In the nonglaciated, low-seismicity central Appalachians, these are dominantly floods and landslides. Evaluation of the role of catastrophic events in landscape evolution includes assessment of...
Viking landing sites, remote-sensing observations, and physical properties of Martian surface materials
H. J. Moore, B. M. Jakosky
1989, Icarus (81) 164-184
Important problems that confront future scientific exploration of Mars include the physical properties of Martian surface materials and the geologic processes that formed the materials. The design of landing spacecraft, roving vehicles, and sampling devices and the selection of landing sites, vehicle traverses, and sample sites will be, in part,...
Reactive iron transport in an acidic mountain stream in Summit County, Colorado: A hydrologic perspective
Diane M. McKnight, K.E. Bencala
1989, Geochimica et Cosmochimica Acta (53) 2225-2234
A pH perturbation experiment was conducted in an acidic, metal-enriched, mountain stream to identify relative rates of chemical and hydrologic processes as they influence iron transport. During the experiment the pH was lowered from 4.2 to 3.2 for three hours by injection of sulfuric acid. Amorphous iron oxides are abundant...
The campi flegrei (Italy) geothermal system: A fluid inclusion study of the mofete and San Vito fields
Vivo B. de, H. E. Belkin, M. Barbieri, W. Chelini, P. Lattanzi, A. Lima, L. Tolomeo
1989, Journal of Volcanology and Geothermal Research (36) 303-326
A fluid inclusion study of core from the Mofete 1, Mofete 2, Mofete 5, San Vito 1, and San Vito 3 geothermal wells (Campi Flegrei, Campania, Italy) indicates that the hydrothermal minerals were precipitated from aqueous fluids (??CO2) that were moderately saline (3-4 wt.% NaCl equiv.) to hypersaline (> 26...
Convergance experiments with a hydrodynamic model of Port Royal Sound, South Carolina
J. K. Lee, R.W. Schaffranek, R.A. Baltzer
1989, Conference Paper
A two-demensional, depth-averaged, finite-difference, flow/transport model, SIM2D, is being used to simulate tidal circulation and transport in the Port Royal Sound, South Carolina, estuarine system. Models of a subregion of the Port Royal Sound system have been derived from an earlier-developed model of the entire system having a grid size...
Large-scale magnetic field perturbation arising from the 18 May 1980 eruption from Mount St. Helens, Washington
R.J. Mueller, M.J.S. Johnston
1989, Physics of the Earth and Planetary Interiors (57) 23-31
A traveling magnetic field disturbance generated by the 18 may 1980 eruption of Mount St. Helens at 1532 UT was detected on an 800-km linear array of recording magnetometers installed along the San Andreas fault system in California, from San Francisco to the Salton Sea. Arrival times of the disturbance...
Review of magnetic and electric field effects near active faults and volcanoes in the U.S.A.
M.J.S. Johnston
1989, Physics of the Earth and Planetary Interiors (57) 47-63
Synchronized measurements of geomagnetic field have been recorded along 800 km of the San Andreas fault and in the Long Valley caldera since 1974, and during eruptions on Mount St. Helens since 1980. For shorter periods of time, continuous measurements of geoelectric field measurements have been made on Mount St....
The nature of the crust in the Yukon-Koyukuk province as inferred from the chemical and isotopic composition of five Late Cretaceous to Early Tertiary volcanic fields in western Alaska
E. Moll-Stalcup, Joseph G. Arth
1989, Journal of Geophysical Research Solid Earth (94) 15989-16020
Late Cretaceous and early Tertiary volcanic and plutonic rocks in western Alaska comprise a vast magmatic province extending from the Alaska Range north to the Arctic Circle, south to Bristol Bay, and west to the Bering Sea Shelf. The chemical and isotopic composition of five of these Late Cretaceous to...
Comparison of seismic waveform inversion results for the rupture history of a finite fault: Application to the 1986 North Palm Springs, California, earthquake
S. Hartzell
1989, Journal of Geophysical Research Solid Earth (94) 7515-7534
The July 8, 1986, North Palm Springs earthquake is used as a basis for comparison of several different approaches to the solution for the rupture history of a finite fault. The inversion of different waveform data is considered; both teleseismic P waveforms and local strong ground motion records. Linear parametrizations for slip...
Problems of snowmelt runoff modelling for a variety of physiographic and climatic conditions
G.H. Leavesley
1989, Hydrological Sciences Journal (34) 617-634
Problems include: a) definition of the spatial and temporal distribution of model input; b) measurement or estimation of snow accumulation, snowmelt, and runoff process parameters for a range of applications and scales; and c) development of accurate short term and long term snowmelt runoff forecasts. Procedures being investigated to solve...
Patterns of sediment accumulation in the tidal marshes of Maine
M.E. Wood, J. T. Kelley, D. F. Belknap
1989, Estuaries (12) 237-246
One year's measurements of surficial sedimentation rates (1986-1987) for 26 Maine marsh sites were made over marker horizons of brick dust. Observed sediment accumulation rates, from 0 to 13 mm yr-1, were compared with marsh morphology, local relative sea-level rise rate, mean tidal range, and ice rafting activity. Marshes with...
Accounting for intracell flow in models with emphasis on water table recharge and stream-aquifer interaction: 1. Problems and concepts
Donald G. Jorgensen, Donald C. Signor, Jeffrey L. Imes
1989, Water Resources Research (25) 669-676
Intracell flow is important in modeling cells that contain both sources and sinks. Special attention is needed if recharge through the water table is a source. One method of modeling multiple sources and sinks is to determine the net recharge per cell. For example, for a model cell containing both...
Morphology and stratigraphy of small barrier-lagoon systems in Maine
W. Duffy, D. F. Belknap, J. T. Kelley
1989, Marine Geology (88) 243-262
The coast of Maine contains over 200 individual barrier-lagoon systems, most quite small, with an aggregate length of nearly 100 km. Although they represent less than 5% of the tidally influenced coastline of Maine, they are widely distributed and occur in...
