A number of small lead/zinc occurrences are hosted by grey plant-debris-rich sandstone of the Late Carboniferous of the Canadian Maritimes. This paper documents field observations on the geological environment of one of these occurrences at Meadowville, Nova Scotia. The aim of the paper is to comment on the possible extent of this occurrence, to provide field criteria for exploration for Carboniferous sandstone lead/zinc deposits, and to provide data for genetic modelling of this type of deposit.

The final year of the Nechako NATMAP project to study the geology of central British Columbia was used to research information collected in the field & laboratory, and to compile & document the study results. This article includes a review of upcoming publications & other products, by type of product: maps, journal articles, conference presentations, and computer products, as well as ongoing research on petrology, palaeontology, terrane characterization, tectonics & structure, and Quaternary geology.

Describes a geologic mapping project in the area of the Nechako reservoir in central interior British Columbia. Includes description of regional geology, stratigraphic units, volcanic & plutonic rocks, and geologic structure. Evidence for two periods of deformation of Hazelton Group rocks in the study area is discussed.

This book constitutes the thoroughly refereed first three workshops on Uncertainty Reasoning for the Semantic Web (URSW), held at the International Semantic Web Conferences (ISWC) in 2005, 2006, and 2007. The 22 papers presented are revised and strongly extended versions of selected workshops papers as well as invited contributions from leading experts in the field and closely related areas. The present volume represents the first comprehensive compilation of state-of-the-art research approaches to uncertainty reasoning in the context of the semantic Web, capturing different models of uncertainty and approaches to deductive as well as inductive reasoning with uncertain formal knowledge.

As the importance and dependence of specific mineral commodities increase, so does concern about their supply. The United States is currently 100 percent reliant on foreign sources for 20 mineral commodities and imports the majority of its supply of more than 50 mineral commodities. Mineral commodities that have important uses and face potential supply disruption are critical to American economic and national security. However, a mineral commodity's importance and the nature of its supply chain can change with time; a mineral commodity that may not have been considered critical 25 years ago may be critical today, and one considered critical today may not be so in the future. The U.S. Geological Survey has produced this volume to describe a select group of mineral commodities currently critical to our economy and security. For each mineral commodity covered, the authors provide a comprehensive look at (1) the commodity's use; (2) the geology and global distribution of the mineral deposit types that account for the present and possible future supply of the commodity; (3) the current status of production, reserves, and resources in the United States and globally; and (4) environmental considerations related to the commodity's production from different types of mineral deposits. The volume describes U.S. critical mineral resources in a global context, for no country can be self-sufficient for all its mineral commodity needs, and the United States will always rely on global mineral commodity supply chains. This volume provides the scientific understanding of critical mineral resources required for informed decisionmaking by those responsible for ensuring that the United States has a secure and sustainable supply of mineral commodities.