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Publication Extents

Not all publications have extents, not all extents are completely accurate
Equilibrium coexistence of three amphiboles
P. Robinson, H.W. Jaffe, C. Klein Jr., M. Ross
1969, Contributions to Mineralogy and Petrology (22) 248-258
Electron probe and wet chemical analyses of amphibole pairs from the sillimanite zone of central Massachusetts and adjacent New Hampshire indicated that for a particular metamorphic grade there should be a restricted composition range in which three amphiboles can coexist stably. An unequivocal example of such...
Critical review of some multivariate procedures in the analysis of geochemical data
A.T. Miesch
1969, Journal of the International Association for Mathematical Geology (1) 171-184
Simulation experiments have been conducted to examine the potential usefulness of R-mode and Q-mode factor methods in the analysis and interpretation of geochemical data. The R-mode factor analysis experiment consisted of constructing a factor model, using the model to generate a correlation matrix, and attempting to...
Experimental introduction of excess Ar40 into a granitic melt
W.S. Fyfe, M. A. Lanphere, G. B. Dalrymple
1969, Contributions to Mineralogy and Petrology (23) 189-193
Samples of a Precambrian granite were melted in sealed capsules to produce a radiogenic Ar40 atmosphere over the melt. The amount of Ar40 incorporated in the quenched charge was then determined. Under these experimental conditions the amount of argon dissolved in the quenched melt was appreciable and could...
A Rubidium-Strontium study of the Twilight Gneiss, West Needle Mountains, Colorado
F. Barker, Z. E. Peterman, R.A. Hildreth
1969, Contributions to Mineralogy and Petrology (23) 271-282
The Precambrian trondhjemitic Twilight Gneiss (Twilight Granite of CROSS and HOWE, 1905b) of the West Needle Mountains, southwestern Colorado, and its interlayered amphibolite and metarhyodacite yield a Rb-Sr isochron of 1,805±35 m.y. A low initial Sr87/Sr86 ratio of 0.7015 implies that metamorphism of these rocks to amphibolite facies...
Primitive and contaminated basalts from the Southern Rocky Mountains, U.S.A
B. R. Doe, P. W. Lipman, C. E. Hedge, H. Kurasawa
1969, Contributions to Mineralogy and Petrology (21) 142-156
Basalts in the Southern Rocky Mountains province have been analyzed to determine if any of them are primitive. Alkali plagioclase xenocrysts armored with calcic plagioclase seem to be the best petrographic indicator of contamination. The next best indicator of contamination is quartz xenocrysts armored with clinopyroxene. On the rocks and...
History of the geomagnetic field
Richard R. Doell
1969, Journal of Applied Physics (40) 945-954
Direct measurements of the direction and strength of the earth's magnetic field have provided a knowledge of the field's form and behavior during the last few hundreds of years. For older times, however, it has been necessary to measure the magnetism of certain rocks to learn what the geomagnetic field was like. For example, when a...