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We present a granulometric study of emerged pebble beach ridges in the Fort Williams Point, Greenwich Island, Antarctic Peninsula. We studied 8 beach ridges from the shore up to 13.5 m above current sea level. The beach ridges are made of volcanic material from the surrounding relief, but also include...

The Pogo lode gold deposit was discovered in eastern Alaska in the early 1990s and provided the opportunity to study elemental distribution and mobility in the natural environment prior to mine development. Studying mineralized systems prior to mining allows us to compare the natural biogeochemical signature in mineralized versus nonmineralized...

No abstract available....

Precambrian rocks at Mt Meredith underwent granulite-facies metamorphism M1. Zircon isotope dating for two orthogneisses revealed the following age signatures: 1294±3 and 957±4Ma; 1105±5 and 887±2Ma. The oldest ages could reflect the time of orthogneiss protolith crystallization and the latest age determinations date Grenvillian metamorphism. The metamorphic rocks were intruded...

The Florida shelf represents a finite source of economic resources, including commercial and recreational fisheries, tourism, recreation, sand and gravel resources, phosphate, and freshwater reserves. Yet the basic information needed to locate resources, or to interpret and utilize existing data, comes from many sources, dates, and formats. A multi-agency effort...

The Terror Rift is a zone of post-middle Miocene faulting and volcanism along the western margin of the West Antarctic Rift System. A new seismic data set from NSF geophysical cruise NBP04-01, integrated with the previous dataset to provide higher spatial resolution, has been interpreted in this study in order...

The contents of this Annual Report summarize results of monitoring and research from the 2006 field season. The report also contains a summary of nuisance grizzly bear (Ursus arctos horribilis) management actions. The Interagency Grizzly Bear Study Team (IGBST) continues to work on issues associated with counts of unduplicated females with...

Many of the nation's estuaries have been environmentally stressed since the turn of the 20th century and will continue to be impacted in the future. Tampa Bay, one the Gulf of Mexico's largest estuaries, exemplifies the threats that our estuaries face (EPA Report 2001, Tampa Bay Estuary Program-Comprehensive Conservation and...

Billions of tons of desert dust move through the atmosphere each year. The primary source regions, which include the Sahara and Sahel regions of North Africa and the Gobi and Takla Makan regions of Asia, are capable of dispersing significant quantities of desert dust across the traditionally viewed oceanic barriers....

More than 50 million ounces of lode gold resources have been defined in the previous 15 years throughout accreted terranes of interior Alaska and in adjacent continental margin rocks of Yukon. The major deposits in this so-called Tintina Gold Province formed around 105 to 90 million years ago in east-central...

Epigenetic mineral deposits in the Tintina Gold Province are generally characterized by high concentrations of arsenic and antimony in their mineral assemblage. A total of 347 samples (ground water, surface water, and stream sediment) were collected to investigate the distribution and mobility of arsenic and antimony in the environment near...

A new stratigraphic model is presented for the evolution of the Cenozoic Victoria Land Basin of the West Antarctic Rift, based on integration of seismic reflection and drilling data. The Early Rift phase (?latest Eocene to Early Oligocene) comprises wedges of strata confined by early extensional faults, and which contain...

Analysis of new multibeam bathymetry data and seismic Chirp data acquired over the Cape Fear Slide complex on the U.S. Atlantic margin suggests that at least 5 major submarine slides have likely occurred there within the past 30,000 years, indicating that repetitive, large-scale mass wasting and associated tsunamis may be...

This study is based on about 8400 km of MCS, magnetic and gravity data as well as 20 sonobuoys collected by the Russian Antarctic Expedition during 2003 and 2004 in the Davis Sea and adjacent areas between 80°E and 102°E. Major tectonic provinces and features are identified and mapped in...

Northern Nevada contains ∼360 igneous intrusions subequally distributed among three age groups: middle Tertiary, Cretaceous, and Jurassic. These intrusions are dominantly granodiorite and monzogranite, although some are more mafic. Major-oxide and trace-element compositions of intrusion age groups are remarkably similar, forming compositional arrays that are continuous, overlapping, and essentially indistinguishable....

Microstructures in natural fractures in core recovered offshore from Cape Roberts, Ross Sea, Antarctica, provide new constraints on the relative timing of faulting and sedimentation in the Victoria Land Basin along the Transantarctic Mountain rift flank. This study characterizes the textures, fabrics and grain-scale structures from thin section analysis of...

A Tsunami Pilot Study was conducted for the area surrounding the coastal town of Seaside, Oregon, as part of the Federal Emergency Management's (FEMA) Flood Insurance Rate Map Modernization Program (Tsunami Pilot Study Working Group, 2006). The Cascadia subduction zone extends from Cape Mendocino, California, to Vancouver Island, Canada. The...

The pressure (P) and temperature (T) conditions during metamorphism of a metapelitic sillimanite-garnet gneiss from Clemence Massif, Antarctic Prince Charles Mountains, are estimated using mineral abundance information and petrogenetic P–T pseudosections computed in the chemical system MnO–N2O–CaO–K2O–FeO–MgO–Al2O3– SiO2–H2O–TiO2–Fe2O3 (MnNCKFMASHTO). Calculated mineral equilibria for the appropriate bulk composition predict that the observed...

Some of the most interesting features of the geomagnetic field and its time variations are displayed in polar areas. Observatory monthly means usually provide an excellent opportunity to study the temporal changes of the magnetic field at a given location. Unfortunately, on the Antarctic continent the distribution of the permanent ground- based observatories...

The West Antarctic rift system (WARS) is the product of multiple stages of intracontinental deformation from Jurassic to Present. The Cretaceous rifting phase accomplished >100 percent extension across the Ross Sea and central West Antarctica, and is widely perceived as a product of pure shear extension orthogonal to the Transantarctic...

We examine seller tactics in 1177 eBay auctions. The largest volume sellers make rather homogeneous choices; smaller sellers are more heterogeneous. Some tactics, such as starting the auction with a ‘Buy it Now’ offer, appear to increase revenue. Perhaps due to intense competition, however, the overall impact of most tactics...

Thick accumulations of ice, called “aufeis,” form during winter along stream and river valleys in arctic and subarctic regions. In high-gradient alpine streams, aufeis forms mostly as a result of ground-water discharge into the stream channel. The ice occludes this discharge, perturbing the steady-state condition, and causing an incremental rise...

The 2006 SHALDRIL II cruise was conducted in the northwestern Weddell Sea, with primary drilling targets in the James Ross Basin. A site drilled along the northern edge of the James Ross Basin sampled either latest Eocene or earliest Oligocene deposits, providing a lower chronostratigraphic benchmark for our seismic stratigraphic...

Using existing and new seismic reflection data, new and updated correlations of late Oligocene-early Miocene RSS-2 strata were made between the southern parts of Ross Sea basins. Previous studies documented Cretaceous extension across much of Ross Sea. We interpret that Cenozoic extension also occurred across Ross Sea. Subsidence during and...

Recent works show that organic matter accumulation in some soils from coastal Antarctica is higher than previously expected. The objective of the present work was to estimate the organic C stocks for soils from maritime Antarctica. Cryosols from subpolar desert landscapes presented the lowest organic C stocks. Ornithogenic soils are...