Publications

No abstract available.

Single-channel seismic reflection profiles show evidence for areas of significant gas accumulation at the head of the Cape Fear Slide on the continental rise oft North Carolina. Gas accumulation appears to occur beneath a gas hydrate seal in landward-dipping strata and in domed strata associated with diapirism. In addition, gas venting may have occurred near diapirs located at the head...

No abstract available.

We have modelled stratigraphic sequences to aid in deciphering the sedimentary response to sea-level change. Sequence geometry is found to be most sensitive to sea level, but other factors, including subsidence rate and sediment supply, can produce similar changes. Sediment loading and compaction also play a major role in generating accommodation, a factor often neglected in sequence...

A bypass system for postspawned American shad Alosa sapidissima began operation in 1980 on the Connecticut River canal system at Holyoke Dam. The purpose of the bypass was to enable downstream migrants that enter the canal to exit and avoid death due to delay or passage through hydroelectric turbines at water use facilities. The bypass system had the following elements: (1) an underwater...

The 40Ar/39Ar ages of a sanidine clast from a melt-matrix breccia of the Manson, Iowa, impact structure (MIS) indicate that the MIS formed 73.8 ± 0.3 million years ago (Ma) and is not coincident with the Cretaceous-Tertiary boundary (64.43 ± 0.05 Ma). The MIS sanidine is 9 million years older than 40Ar/39Ar age spectra of MIS shock-metamorphosed microcline and melt-matrix breccia...

Low annual survival of hatching-year (HY) females is a critical management concern for canvasbacks (Aythya valisineria), and may contribute substantially to reduced reproductive potential and the male-biased sex ratio of the species. To evaluate the contribution of mortality on a traditional wintering area to low annual survival, we estimated survival rates of HY female canvasbacks...

Phenacosaurus neblininus, new species, was discovered during the 1984-1985 expedition to Cerro de la Neblina on the Venezuelan-Brazilian border. It was found at several highland camps (> 1600 m) but seems unaccountably rare, with only six specimens collected. The closest relative of this lizard may be another new species (Williams et al., MS) known from a single specimen from Chimanta...

Transmission risk of Lyme disease at a site can be estimated using the probability of exposure (P1 = probability of being bitten by at least one infected tick); P1 =1 - (1 - kt)n, where n = number of tick bites per person and kt = spirochete prevalence in questing ticks. This probability is more directly related to the likelihood of acquiring Lyme disease than the standard measure of...

Northern pintails (Anas acuta) exist as a single circumpolar breeding population but display weak fidelity to given breeding sites. If fidelity to wintering areas is strong, management on wintering grounds may allow local winter populations to increase. Thus, I delineated reference areas for wintering areas based on recovery data for pintails banded during the winter (Dec-Feb) in the...

From 1950 through 1988, the continental breeding population of northern pintails (Anas acuta) varied from 2.0 million to 9.9 million. Because pintails have high fidelity to certain wintering grounds along coasts and large bodies of water, management on these wintering areas may increase population size if changes in winter survival rate are related to changes in population size. I used...

No abstract available.