Publications

The adsorption of Se by goethite was studied as a function of time (10 min–24 h), temperature (295.5 and 303.5 K), pH (4–11), particle concentration (3–300 mg/L), total Se concentration (0.02–5 × 10−5 M), oxidation state [Se(IV) and Se(VI)], and competing anion concentration [(anion)/(Se(IV) = 0.25 to 50 000] in order to assess the influence of these factors on Se mobility. The data indicate that

The stable isotopes of carbon and sulfur in a major marine sedimentary phosphate deposit from the northwestern United States (the Phosphoria Formation of Permian age) characterize the chemical properties of the depositional environment. The δ34S and δ13C analyses suggest deposition under conditions of variable redox from a solution the acidity of which was controlled by reaction with carbonate roc

No abstract available.

Seismic‐reflection profiles over the sediment‐filled Escanaba Trough at the southern Gorda Ridge reveal a series of volcanic centers that pierce the sediment. The volcanic edifices are 3 to 6 km in diameter and are spaced at 15 to 20 km intervals along the axis of the trough. The volcanic intrusions have uplifted the sediment as much as 100 m, and in places fresh basaltic flows are exposed at the

Alluvium deposited in a reservoir from 1937 to 1976 records the sediment-yield history of a small (2.8 km2), high-relief basin in semiarid southern Utah. Stratification in the alluvium shows that sediment was deposited in the reservoir only 21 times in 38 yr, a runoff recurrence interval of 1.8 yr. Thus, on average, the particular combination of rainfall intensity, duration, and antecedent moistur

Michael Fuller, author of a similar overview four years ago, concluded that “...the next quadrennium promises to be a most interesting one, with plenty to keep us busy.” The 11 review papers that follow support his prediction; research in geomagnetism and paleomagnetism indeed has flourished over the last four years. In this brief overview, I will attempt to summarize what I perceive as important

No abstract available.

The stable isotopes of carbon and sulfur in a major marine sedimentary phosphate deposit from the northwestern United States (the Phosphoria Formation of Permian age) characterize the chemical properties of the depositional environment. The δ34S and δ13C analyses suggest deposition under conditions of variable redox from a solution the acidity of which was controlled by reaction with carbonate roc

Common lead isotopic compositions have been determined on feldspars from meta-igneous rocks from nine tectono-stratigraphic terranes or subterranes in east-central Alaska. Most of the terranes have distinct and well-defined signatures in terms of isotopic composition; thus, most can be distinguished on conventional lead isotopic diagrams. Lead isotopic ratios provide evidence for (1) possible sour

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No abstract available.

No abstract available.