Origin of magnetite and pyrrhotite in carbonaceous chondrites
J.M. Herndon, M.W. Rowe, E.E. Larson, D.E. Watson
1975, Nature (253) 516-518
CARBONACEOUS chondrites, although comprising only about 2% of known meteorites, are extremely interesting for scientific investigation. Their mineral constitution, and the correspondence between their bulk chemical composition and the solar abundance of condensable elements, indicate that minimum chemical fractionation and thermal alteration have occurred. The mineral...
Analysis of the rate of wildcat drilling and deposit discovery
L.J. Drew
1975, Journal of the International Association for Mathematical Geology (7) 395-414
The rate at which petroleum deposits were discovered during a 16-yr period (1957–72) was examined in relation to changes in a suite of economic and physical variables. The study area encompasses 11,000 mi2 and is located on the eastern flank of the Powder River Basin. A two-stage...
Oats may grow better in water depleted in oxygen 18 and deuterium
Jim D. Gleason, Irving Friedman
1975, Nature (256) 305
WHILE growing oats at different temperatures in water of different 18O and deuterium (D) abundances, we noticed that oats grown in Antarctic water in which is depleted in 18O and D by −49‰ and −400‰, relative to standard mean ocean water (SMOW used as a comparative reference in...
A major geothermal anomaly in the Gulf of California
L.A. Lawver, D.L. Williams, R. P. Von Herzen
1975, Nature (257) 23-28
We have mapped a 3-km wide, high heat flow anomaly with a maximum value of 30 μcalorie cm −2 s−1 within a zone of seafloor extension in the central Gulf of California. From seismic reflection data and thermal modelling we suggest that the anomaly is caused by a 1-km wide...
Geologic setting of Boulder 1, Station 2, Apollo 17 landing site
E.W. Wolfe
1975, The Moon (14) 307-314
Boulder 1 at Station 2 is one of three boulders sampled by Apollo 17 at the base of the South Massif, which rises 2.3 km above the floor of a linear valley interpreted as a graben formed by deformation related to the southern Serenitatis impact. The...
Two models for earthquake forerunners
V.I. Mjachkin, W.F. Brace, G.A. Sobolev, James H. Dieterich
1975, Pure and Applied Geophysics PAGEOPH (113) 169-181
Similar precursory phenomena have been observed before earthquakes in the United States, the Soviet Union, Japan, and China. Two quite different physical models are used to explain these phenomena. According to a model developed by US seismologists, the so-called dilatancy diffusion model,...
Ages of fossil bones from British interglacial sites
Barney J. Szabo, D. Collins
1975, Nature (254) 680-682
THE time gap between the upper limit of radiocarbon dating (≈60,000 yr BP) and the lower limit of dates generally obtainable using the K–Ar method (≈250,000 yr BP) accounts for the scarcity of dates for the last two interglaciations (the Ipswichian and Hoxnian of Britain; the...
U-Th-Pb systematics of selected samples from Apollo 17, Boulder 1, Station 2
P.D. Nunes, M. Tatsumoto
1975, The Moon (14) 463-471
Nine U-Th-Pb whole-rock analyses of selected brecciated materials from sample 72215 and one analysis of a pigeonite basalt clast from 72275 are presented. Both samples are from Boulder 1, Apollo 17. These data supplement previous Boulder 1 U-Th-Pb analyses of samples 72275 and 72255. U and Th concentrations indicate that...
Recent sedimentary history of Lake Monona, Wisconsin
Gilbert C. Bortleson, G.F. Lee
1975, Water, Air, & Soil Pollution (4) 89-98
Chemical analyses from two short cores in Lake Monona show that pronounced changes in chemical stratigraphy have occurred since white man moved into Madison and southern Wisconsin and began modifying the area. Since the mid to late 1800's, there has been an appreciable increase in P,...
The orthoenstatite to clinoenstatite transformation by shearing and reversion by annealing: Mechanism and potential applications
R. S. Coe, Stephen H. Kirby
1975, Contributions to Mineralogy and Petrology (52) 29-55
Clinoenstatite (CE) was produced by deforming single-crystal specimens of ortho-enstatite (OE) in several different sorta of experiments. Examination with light and trans-mission electron microscopes shows that the transformation is coherent and involves a macroscopic shear on (100) [001] through an angle of 12.8±1.3 °, in good...
Anomalous delays of teleseismic P waves in Yellowstone National Park
H.M. Iyer
1975, Nature (253) 425-427
TELESEISMIC P waves recorded by a short-period seismic network, comprising 12 stations, in Yellowstone National Park, show anomalous delays of 1–2 s in their travel times in the central region of the park relative to the surrounding area. To explain this phenomenon, I propose that a...
Stable sliding preceding stick-slip on fault surfaces in granite at high pressure
J.D. Byerlee, R. Summers
1975, Pure and Applied Geophysics (113) 63-68
The distance of stable sliding before sudden slip on fault surfaces in granite decreases rapidly as the confining pressure is increased. At a pressure of 6 kb the amount of stable creep is very small or absent. Two orders of magnitude change in strain rate has...
Compositional evidence regarding the influx of interplanetary materials onto the lunar surface
J. T. Wasson, W. V. Boynton, C. L. Chou, Philip A. Baedecker
1975, The Moon (13) 121-141
Siderophilic element/Ir ratios are higher in mature lunar soils from highlands sites than in those from mare sites. We infer that the population of materials responsible for the early intense bombardment of the Moon had high ratios, and that the population responsible for the essentially constant flux has low ratios....
The nature of surface tilt along 85 km of the San Andreas fault-preliminary results form a 14-instrument array
C.E. Mortensen, M.J.S. Johnston
1975, Pure and Applied Geophysics PAGEOPH (113) 237-249
The continuous monitoring of surface deformation near active faults is clearly necessary for an understanding of elastic strain accumulation and elastic and anelastic strain release associated with earthquakes. Fourteen 2-component tiltmeters have been installed in shallow boreholes along 85 km of the currently most active section...
Lead isotope relations in oceanic Ridge basalts from the Juan de Fuca-Gorda Ridge area N.E. Pacific Ocean
S. E. Church, M. Tatsumoto
1975, Contributions to Mineralogy and Petrology (53) 253-279
Lead isotopic analyses of a suite of basaltic rocks from the Juan de Fuca-Gorda Ridge and nearby seamounts confirm an isotopically heterogeneous mantle known since 1966. The process of mixing during partial melting of a heterogeneous mantle necessarily produces linear data arrays that can be interpreted...
Lava flows in mare imbrium: An evaluation of anomalously low earth-based radar reflectivity
G. G. Schaber, T.W. Thompson, S.H. Zisk
1975, The Moon (13) 395-423
The lunar maria reflect two to five times less Earth-based radar power than the highlands, the spectrally blue maria surfaces returning the lowest power levels. This effect of weakening signal return has been attributed to increased signal absorption related to the electrical and magnetic characteristics of...
Arctic palaeosalinities during late Cainozoic time
Y. Herman, J. R. O’Neil
1975, Nature (258) 591-595
DURING the late Cainozoic, alternations between interglacial and glacial conditions, manifested by waning and waxing of continental ice sheets coincided with the rise and fall of seawater temperatures. Our palaeontological and oxygen isotope data indicate that although the major oceans and low latititude seas underwent large...
Lunar magnetic anomalies and the Cayley formation
D.E. Stuart-Alexander
1975, Nature (253) 658
[No abstract available]...
Effects of environmental pollutants on Connecticut and Maryland ospreys
Stanley N. Wiemeyer, P.R. Spitzer, W.C. Krantz, T. G. Lamont, E. Cromartie
1975, Journal of Wildlife Management (39) 124-139
Osprey (Pandion haliaetus) eggs were exchanged between Connecticut and Maryland osprey nests in 1968 and 1969 to test the hypothesis that the decline in reproductive success of Connecticut ospreys was caused by something within the external environment of the eggs. Incubation of 30 Connecticut osprey eggs by Maryland ospreys did...
[Book review] Helping and communal breeding in birds: ecology and evolution by Jerram L. Brown
C.S. Robbins
1975, American Birds (29) 301
[Book review] Birds and Marshes of the Chesapeake Bay Country, by B. Meanley
Matthew C. Perry
1975, Maryland Birdlife (31) 125
Notes on winter feeding behavior and molt in Wilson's phalaropes
J. Burger, M. Howe
1975, The Auk (92) 442-451
Wilson's Phalaropes, Steganopus tricolor, migrate in late summer from the prairie regions of North America to their wintering grounds in the highlands of Peru and the inland and coastal waters of Chile, Bolivia, Paraguay, Uruguay, and Argentina (Holmes 1939, Meyer de Schauensee 1970). Reports on these birds from their wintering...
Emperor penguins nesting on Inaccessible Island
G.M. Jonkel, G.A. Llano
1975, Antarctic Journal of the United States (9) 93-95
Emperor penguins were observed nesting on Inaccessible I. during the 1973 winter. This is the southernmost nesting of emperor penguins thus far recorded; it also could be the first record of emperors attempting to start a new rookery. This site, however, may have been used by emperors in the past....
Recovery planning for the California condor
S.R. Wilbur
1975, Outdoor California (36) 10-11
California condor plumage and molt as field study aids
S.R. Wilbur
1975, California Fish and Game (61) 144-148
An analysis is made of the reliability of plumage and molt characteristics of the California condor for estimating age and identifying individual birds. Neither character seems sufficiently reliable to use in more than a general way....
