Hydrogeologic and water-quality data for the East Management Unit of Dover Air Force Base, Kent County, Delaware, 1995-96
Explore the source record for details and available documents.
Open-File Report↗
Geology topics
V. C. Smith
Publications and source records attributed to V. C. Smith.
Precambrian petrochemistry of the northern Park Range, Colorado, and its implications for studies of crustal derivation
Explore the source record for details and available documents.
Professional Paper↗
Quantitative chemical analysis of lunar samples
In three lunar samples the high titanium contents previously reported were confirmed. Water and ferric oxide were absent.
Science↗
Biotites from granitic rocks of the central Sierra Nevada batholith, California
Biotites from plutonic rocks of the central Sierra Nevada and Inyo Mountains, California, have been examined and characterized by powder X-ray diffraction and optical and chemical methods. Compositions of the biotites define a trend in the compositional triangle Fe+3 Fe+2Mg. When related to the experimentally studied ternary system KFe 3 +3AlSisO 12 H- 1 -KFe 3 +2 AlSi 3 O 10 (OH) 2 -KMg 3 AlSi 3 O 10 (OH) 2 and coupled with the estimated positions of biotite solid solutions for different oxygen buffers, the trend suggests that oxygen fugacities in magmas during biotite crystallization were slightly higher than those defined by the Ni-NiO buffer. The compositional data also suggest that magmas were ‘buffered’ with respect to oxygen by oxides existing within the magmas themselves. Correlation between the Fe/(Fe+Mg) ratio, an inferred temperature indicator, and other elements is generally poor, which suggests that factors other than temperature at the time of crystallization exerted an important influence on compositions.
California↗
Loss of halogens from crystallized and glassy silicic volcanic rocks
One hundred and sixty-four F and Cl analyses of silicic welded tuffs and lavas and glass separates are presented. Comparison of the F and Cl contents of crystallized rocks with those of nonhydrated glass and hydrated glassy rocks from the same rock units shows that most of the halogens originally present were lost on crystallization. An average of about half of the F and four-fifths of the Cl originally present was lost. Analyses of hydrated natural glasses and of glassy rocks indicate that in some cases significant amounts of halogens may be removed from or added to hydrated glass through prolonged contact with ground water. The data show that the original halogen contents of the groundmass of a silicic volcanic rock can be reliably determined only from nonhydrated glass.
Geochimica et Cosmochimica Acta↗
Diabase sheets of the Taylor Glacier region, Victoria Land, Antarctica, with sections on petrography and sections on chemistry
Explore the source record for details and available documents.
Professional Paper↗
Spectrophotometric determination of fluorine in silicate rocks
The rock powder is sintered with a sodium carbonate flux containing zinc oxide and magnesium carbonate, the sinter-cake leached with water and the resulting solution filtered. Fluorine is separated from the acidified filtrate by steam distillation and determined spectrophotometrically by means of a zirconium-SPADNS reagent. If a multiple-unit distillation apparatus is used, 12 determinations can be completed per man-day.
Talanta↗