Relationship between paleotemperatures of metamorphic dolomites and ESR determined Mn(II) partitioning ratios

An Electron Spin Resonance (ESR) study of the distribution of Mn(II) between Mg sites and Ca sites in 28 contact metamorphic dolomite samples suggests that the distribution is temperature sensitive. The data can be modelled by alternative interpretations. In the first a polynomial equation approximates the trend of the data suggesting an exponential relation with Mn(II) ratios decreasing to a stable value of 10 with increasing temperature (to near 900°C). The second suggests two groups of dolomites. One group, close to the intrusion (< 100 m), has a low partitioning ratio (10 to 30), possibly increasing linearly with increasing distance from the intrusive contact. The second group (100 to 400 m) increases in scatter and distribution ratio (20 to 215) with increasing distance. Whatever the detailed relationship, we conclude that Mn partitioning is related to the thermal halo of the intrusion and that lower ratios result from higher temperatures. Mn(II) partitioning ratios may yield absolute paleotemperature data when calibrated against other techniques.     

Climatic variations in north-central Chile from 1866 to 1971

Climatic variations in north-central Chile during the period 1866–1971 are depicted by plotting annual rainfall and other climatic data as cumulative departures from the mean. The variations are compared with world wide climatic fluctuations and a possible intensifying of existing drought conditions is forecast. The effects of decrease in precipitation over the last decade on water supplies are discussed in relation to agriculture and the processing of copper ore.     

The ecological role of fire in the Jackson Hole area,northwestern Wyoming

Fire-history investigations in the Jackson Hole area of northwestern Wyoming reveal that most current stands of aspen and lodgepole pine regenerated following extensive fires between 1840 and 1890 and that widespread fires occurred in the 1600s and 1700s. White man's major effect on the fire incidence has been the successful suppression during the past 30–80 yr. Successional changes in the absence of fire include the deterioration of aspen stands, massive invasions of subalpine fir in lodgepole pine stands, great increase in conifer cover, heavy fuel buildups in lodgepole pine and Douglas fir stands, and increase in sagebrush and other shrubs. Steps are being taken, starting in 1972, to allow fire to play a more natural role in Grand Teton and Yellowstone National Parks. Teton National Forest plans experimental prescribed burning to determine whether fire can stimulate successful aspen regeneration in the presence of large numbers of wintering elk.     

Predicted CO2 emissions from maceral concentrates of high volatile bituminous Kentucky and Illinois coals

A large collection of well-characterized coals, documented in the Center for Applied Energy Research's (CAER) database, was used to estimate the CO₂ content of maceral concentrates from Kentucky and Illinois high volatile bituminous coals. The data showed no correlation between CO₂ versus coal ranks and between CO₂ versus maceral content. Subsequently, eight sets of low-ash density-gradient centrifugation (DGC) maceral concentrates from five coal beds were examined, spanning in the high volatile rank range. Heating value was not determined on the concentrates, but instead was calculated using the Mott–Spooner formula. There was a good correlation between predicted CO₂ and maceral content for the individual iso-rank (based on vitrinite reflectance, analyzed on whole (parent) coal) sets. In general, the predicted CO₂ increases from liptinite-rich through vitrinite-rich to inertinite-rich concentrates (note: no “concentrates” are absolutely monomaceral).