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Page 6487, results 162151 - 162175

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Publication Extents

Not all publications have extents, not all extents are completely accurate
Ecological relationships of breeding blue-winged teal to prairie potholes
Rod C. Drewien, P. F. Springer
1969, Report Series 6
Ecology of breeding blue-winged teal (Anas discors) was studied on the Waubay Study Area in Day County, South Dakota, in 1965 and 1966. Breeding pair use of the wetland habitat and importance of Type 1 ponds in the wetland complex were evaluated. Changes in breeding pair densities and wetland habitat...
Aging small Canada geese by neck plumage
K.F. Higgins, L.J. Schoonover
1969, Journal of Wildlife Management (33) 212-214
The neck plumage method, a new technique for separating immature from adult Canada geese (Branta canadensis) in the hand, was evaluated by comparison with the notched tail feather and cloacal examination methods. Two (1.4 percent) of 141 geese examined were misaged, resulting in a 6 percent error in the immature-adult...
Etching fission tracks in zircons
C. W. Naeser
1969, Science (165) 388-388
A new technique has been developed whereby fission tracks can be etched in zircon with a solution of sodiuim hydroxide at 220°C. Etching...
Thermochemical study of the system Fe-As-S
P. B. Barton Jr.
1969, Geochimica et Cosmochimica Acta (33) 841-857
The results of Toulmin and Barton (1964) for the Fe-S system have been combined with a series of new measurements on As-bearing assemblages in the 500°–850°C temperature range to derive data on the free energies, enthalpies, and entropies of formation for arsenopyrite, loellingite, orpiment, realgar,...
Some triple-filament lead isotope ratio measurements and an absolute growth curve for single-stage leads
J. S. Stacey, M.E. Delevaux, T.J. Ulrych
1969, Earth and Planetary Science Letters (6) 15-25
Triple-filament analyses of three standard lead samples are used to calibrate a mass spectrometer in an absolute sense. The bias we measure is 0.0155 percent per mass unit, and the precision (for 95% confidence limits) is ±0.13% or less for all ratios relative to204Pb. Although its precision is not quite...
40Ar/36Ar analyses of historic lava flows
G. B. Dalrymple
1969, Earth and Planetary Science Letters (6) 47-55
The ratio40Ar/36Ar was measured for 26 subaerial historic lava flows. Approximately one-third of the samples had40Ar/36Ar ratios either higher or lower than the atmospheric value of 295.5 at the 95% confidence level. Excess radiogenic40Ar in five flows ranged from about 1 ×...
The determination of the acoustic parameters of volcanic rocks from compressional velocity measurements
R. D. Carroll
1969, International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts (6) 557-579
A statistical analysis was made of the relationship of various acoustic parameters of volcanic rocks to compressional wave velocities for data obtained in a volcanic region in Nevada. Some additional samples, chiefly granitic rocks, were also included in the study to extend the range of parameters and the variety of...
Planktonic diatoms of Lake Ontario
Jerry F. Reinwand
1969, Technical Report 14
The major species of diatoms in surface collections from Lake Ontario in September 1964 were Asterionella formosa, Fragilaria crotonensis, and Tabellaris fenestrata. Dominant species in the deep-water samples were Stephanodiscus astraea, S. astraea var. mintula, and F. crotonensis. The diatom flora in surface collections varied among several stations in the...
Lake Ontario phytoplankton, September 1964
Roann E. Ogawa
1969, Technical Report 14
Phytoplankton counts on samples collected in Lake Ontario on September 8-18, 1964, showed that green algae were the dominant plankters and diatoms were of secondary importance. The greatest abundance of phytoplankton was close to shore from Toronto, along the southern shore of the lake, and up the eastern shore to...
Rearing of sea lamprey, Petromyzon marinus, embryos in distilled water
George W. Piavis, John H. Howell
1969, Copeia (1969) 204-205
Most embryological studies of lampreys in the Great Lakes have been conducted with filtered water from Lake Huron. Although this water was entirely satisfactory for the earlier work, the present need for knowledge of the effects of various compounds on embryological development requires that the initial medium be sterile....