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Donald C. Noble

Publications and source records attributed to Donald C. Noble.

12 recordsLinked to original sources
USGS1978

Comendite (peralkaline rhyolite) and basalt in the Mitu Group, Peru: Evidence for Permian-Triassic lithospheric extension in the central Andes

The Mitu Group consists of generally coarse clastic strata and volcanic rock of Permian and (or) Triassic age filling elongate basins that parallel the general structural trend of the Peruvian Andes. Volcanic rocks of the Mitu Group include peralkaline and nonperalkaline rhyolite and subalkaline basalt. To our knowledge, the peralkaline rhyolites are the first of this rock type reported from South America. The presence of appreciable volumes of peralkaline rhyolite and basalt, supports the interpretation that the Mitu Group was deposited in major graben structures that resulted from lithospheric extension produced by rifting or possible backarc extension.

central Andes Mountains↗
USGS1973

Reconnaissance study of the strontium isotopic composition of Cenozoic volcanic rocks in the northwestern Great Basin

Sixteen mafic and intermediate lava flows of Eocene to Pleistocene age from the northwestern Great Basin have initial Sr 87 /Sr 86 ratios of from 0.7029 to 0.7047. Seven upper Miocene mafic and intermediate lava flows have initial ratios of from 0.7037 to 0.7041, suggesting a common source for the Steens Basalt and contemporaneous rocks of the northwestern Great Basin. Values of 0.7047 and 0.7033 obtained on olivine basalts of early Miocene and Quaternary ages, respectively, suggest that these lavas were derived from different source materials than were the late Miocene rocks. Unusually low values of 0.7029 obtained on two specimens of andesite from the Eocene Cedarville Series of Russell (1928) suggest that these lava flows were derived from still another source material. Ten silicic volcanic rocks, most from widespread and voluminous ash-flow sheets and lava complexes, have initial ratios of approximately 0.7023 to 0.7057. Some of the more radiogenic values, obtained on very highly differentiated and strontium-poor rock units, provide only an upper limit for the initial Sr 87 /Sr 86 ratios of the parent magmas. The close similiarity of the strontium isotopic composition of the silicic rocks to those of spatially and temporally associated intermediate lavas supports the concept that the widespread Miocene silicic volcanic rocks of the northwestern Great Basin were produced by the fractional crystallization of enormous volumes of mantle-derived mafic magma. The data also provide indirect support for the interpretation that the relatively radiogenic character of many salic volcanic rocks from other parts of the Great Basin largely reflects the presence of an unusually radiogenic mantle rather than the involvement of crustal material.

California, Idaho, Nevada, Oregon↗
USGS1971

Upper Cenozoic basalts with high Sr87/Sr86 and Sr/Rb ratios, southern Great Basin, western United States

Upper Cenozoic basalts from southwestern Nevada and east-central California are unusually rich in both strontium (~ 1,200 ppm) and Sr 87 (initial Sr 87 /Sr 86 ~ 0.707). The average Rb/Sr ratio of these basalts is too low to have generated the observed Sr 87 /Sr 86 ratio during the 4.6 b.y. of the Earth's existence, and the high strontium contents and low Rb/Sr ratios effectively rule out introduction to the basalts of the high Sr 87 /Sr 86 values through contamination by more radiogenic material during ascent through the crust. Instead, the basalts must have been derived from unusual mantle material in which an originally high Rb/Sr ratio was markedly lowered during an earlier phase of magmatic activity.

Arizona, California, Nevada, Utah↗
USGS1969

Minor-element and revised major-element contents of some Mediterranean pantellerites and comendites

Optical emission spectrographic analysis of three pantellerites from Pantelleria and two comendites from Sardinia show high concentrations of B, Be, Ga, La, Mo, Nb, Sn, Y, Yb, and Zt and low contents of Ba, Co, Cr, Ni, Sr, and V. Minor-element trends of these specimens are very similar to those of pantellerites from southern Nevada and New Zealand and other peralkaline silicic rocks from various localities. Fluorine contents of the Pantellerian specimens range from 0.19 to 0.32 per cent by weight resulting in abnormally high Cl to F ratios. New analyses for MgO, Na 2 O, and K 2 O are almost identical with the values obtained by Zies. Revised major-element compositions and calculated glass-phase compositions for the three Pantellerian specimens are given.

Pantelleria, Sardinia↗