CADMIUM GEOCHEMISTRY OF SOILS AND WILLOW IN A METAMORPHIC BEDROCK TERRAIN AND ITS POSSIBLE RELATION TO MOOSE HEALTH, SEWARD PENINSULA, ALASKA

The regional geochemistry of soil and willow over Paleozoic metamorphic rocks in the Seward Peninsula, Alaska is potentially high in cadmium (Cd), and willow, a preferred browse of moose, bioaccumulates Cd. Local moose show clinical signs of tooth wear and breakage and have been declining in population for unknown reasons. Willow leaves (all variants of Salix pulchra) and A-, B-, and C-horizon soils were sampled near 2 mining prospects suspected to be high in Cd. Although Al, Cd, Co, Cu, Fe, Mo, Ni, Pb, and Zn were examined, our focus in this exploratory study was on the level of Cd in the 3 soil horizons and willow between and within the 2 prospects and their vicinity. We used an unbalanced, one-way, hierarchical analysis of variance (ANOVA) to investigate the geochemistry of soils and willow at various distance scales across the 2 prospect areas that were separated by ~80 km; sites within a location were approximately 0.5 km apart and replicate samples were separated by ~0.05 km. Cd concentration was significantly different in willow between and within sites, and within sites for all soil horizons. Specifically, this exploratory study identified highly elevated levels of Cd in willow growing over Paleozoic bedrock in the Seward Peninsula at both prospects and over the Paleozoic geologic unit in general. Potential negative effects for moose are discussed

Has the Largest Field Been Discovered Yet? PETRIMES and GRASP 25 Years Later

Assessment of undiscovered oil and gas resources has been an important component of energy policy for the governments of the United States and Canada for many years. A pool-size-by-rank statistical procedure is a centerpiece of the Geological Survey of Canada’s Petroleum Exploration and Resource Evaluation System (PETRIMES) and of the U.S. Department of Interior’s Geological Resource Assessment Program (GRASP). Both employ discovery process modeling to make inferences about the number of pools in a play and about parameters of the play’s pool size distribution. The pool-size-by-rank procedure implemented in these two systems abandons a key primitive postulate on which modern discovery process models are based—sampling proportional to pool size and without replacement. This logical disjunction has consequences: the predictive distribution of number of pools remaining to be discovered and the predictive distribution of undiscovered pool sizes generated by use of pool-size-by-rank procedures differ substantially in shape, location and spread from predictive distributions that incorporate sampling proportional to size. Uncertainty about total undiscovered oil and gas in a play is diminished