Abstract The U.S. Geological Survey (USGS) operates the Core Research Center (CRC) in Denver, Colorado, USA, a public access repository of rock cores from over 9800 wells and drill cuttings from over 53 000 wells, primarily from states in or adjacent to the Rocky Mountain Region. Annually, approximately 1400 visitors use the collection for traditional and innovative research. The CRC has an online, searchable database which includes downloadable core photos, analytical data, and thin-section images. When visitors sample for analyses, the results must be returned to the CRC for public dissemination providing immediate, free access to users while sparing the finite, irreplaceable collection from redundant testing. A representative quantity of every core depth is preserved in perpetuity. Studies on CRC materials, paired with new extraction methods, have unlocked new productive deposits. Materials drilled and curated decades ago remain in high demand while materials receiving little attention today may be crucial for future research. The collection provides immediate, inexpensive access to subsurface materials at a fraction of the cost of new drilling, sparing money, time and environmental impacts.

Concentrations of radon-222 in soil gas measured over about 1 yr at a monitoring site in Denver, Colorado, vary by as much as an order of magnitude seasonally and as much as severalfold in response to changes in weather. The primary weather factors that influence soil-gas radon concentrations are precipitation and barometric pressure. Soil characteristics are important in determining the magnitude and extent of the soil’s response to weather changes. The soil at the study site is clay rich and develops desiccation cracks upon drying that increase the soil’s permeability and enhance gas transport and removal of radon from the soil. A capping effect caused by frozen or unfrozen soil moisture is a primary mechanism for preventing radon loss to the atmosphere.

Abstract Questions relating to the past distribution of faunas, floras and sediments, the meaning of distributional patterns, and causes of changes in past distributions have greatly interested many scientists for more than a century. These problems take on added importance when viewed in the context of recent theories of plate tectonics and redistribution of crustal blocks. This volume presents the results of a Research Symposium, which was given at the annual meeting of SEPM in Denver, Colorado on April 18, 1972. The resulting papers view paleogeographic provinces and provinciality over a broad spectrum. The papers are so completely diverse in their approaches to the subject that their concepts and terminologies commonly contrast strongly, the culmination of which should be the vigorous rejuvenation and reexamination of concepts and hypotheses in paleogeography and provinciality.