Glaciers and ice sheets are among the world’s most beautiful and fascinating natural wonders. Whereas today glacier ice covers approximately a tenth of Earth’s land surface, during the ice ages of the last few million years, as much as a third of the land surface was covered by glacier ice. Modern glaciers and ice sheets possess many interesting features that reflect their dynamics, their interaction with landscape, rock, sediment and water, and they also inform us about climate change. The legacy of ice masses is reflected in the presence of a variety of landforms and sediments, many of which are also recorded in the rock record. The value of glaciers to society is immense.

Conventional oil and gas are usually found in pore spaces and fracture openings of sandstones, limestones, and dolomite. Shales, although considered to be important in many cases as source rocks and cap rocks for hydrocarbons, usually do not contain commercial oil and gas. In other words, from the standpoint of production, shales are relatively useless rocks.

If, for example, an exploratory well were drilled and a geologist tried to evaluate whether it had penetrated oil and/or gas accumulations, he would first separate the shaly sections as being of no interest, and then try to find out whether the other sections were oil-(and/or gas-) saturated or watersaturated. <...>

Discriminating productive jasperoids associated with economic gold mineralization from barren jasperoids, those with no known gold association, has long been an objective of Great Basin explorationists. Holland et al. (1988) use factor analysis of a multielement geochemical data set to compare jasperoids associated with Carlin-type gold mineralization with jasperoids in barren systems. They go on to propose a genetic model for Carlin-type deposits based on their interpretation of the factor analysis results. There are problems with their approach, several of which the authors acknowledge. The geologic control for their samples is inadequate, the analytical technique used is inaccurate for several critical elements, and their statistical analysis of the data could be much simpler, easier to interpret, and useful.

This paper presents a detailed comparison of the microboudinage of piedmontite in two different mineralogical hosts, a quartz matrix, and albite porphyroblasts in a siliceous schist, with the aim of clarifying the rheological properties of albite in relation to those of quartz. Stress and strain analyses of the microboudinage confirm that the boudinage took place in the retrograde stage of metamorphism during decreasing temperature, and reveal that albite deformed at the same strain rate as quartz above the plastic-brittle transition temperature of albite.