Publications

No abstract available.

Over 62 percent of the 193,000 metric tons of gold discovered to date is located in four countries and more than 68 percent occurs in four types of mineral deposits. About 55 percent of the 1,740,000 metric tons of silver found is in four countries and 45 percent is in four types of deposits. Fifty-six percent of the 1.52 billion metric tons of discovered copper is from four countries and four typ

The determination of the total age coverage of pelagic bedded chert is particularly important in studies of ancient accretionary complexes because the time span represents the minimum travel time of an oceanic plate before accretion at an island arc or continental margin. The Yolla Bolly terrane of the Franciscan Complex consists of rare metabasalt overlain by bedded radiolarian chert which in tur

Several ophiolitic assemblages occur in the southern New England orogen. The development of these rocks and their relations to the rest of the orogen have major implications for the tectonic evolution of eastern Gondwana. A major, narrow but elongate belt of Early Cambrian suprasubduction zone ophiolite crops out along and near the PeelManning Fault System and is juxtaposed against younger arc and

No abstract available.

No abstract available.

This collection of 19 papers continues the annual series of U.S. Geological Survey reports on geologic investigations in Alaska. Contributions include 14 Articles and 5 shorter Geologic Notes that report results from all corners of the State.USGS activities in Alaska cover a broad spectrum of earth science topics, including the environment, hazards, resources, and geologic framework studies. Three

The Exploratory Studies Facility is a major part of the site characterization activities at Yucca Mountain, Nevada, and the north ramp is the first phase of construction. The N61W trending north ramp will transect the Bow Ridge and Drill Hole Wash faults and numerous minor faults, and traverses two thick welded tuffs and several nonwelded tuff units. A preliminary cross section along the north ram

Alaska is the eastern, subaerial part of a large subcontinent of distinctive tectonic character that serves as an isthmus between nuclear North America, with its fringing belt of allochthonous terranes, and the accreted terranes and volcanic belts that constitute northeastern Russia. Physiographically, this subcontinent, which we name Denalia, is a bulge in the continental platform in the vicinity

South-central Alaska is defined as the region bounded by the Kuskokwim Mountains to the northwest, the basins north of the Alaska Range to the north, the Canadian border to the east, and the Chugach Mountains to the south (Fig. 1). This region, hereafter called the study area, includes the Alaska Range, the Wrangell, Nutzotin, and Talkeetna mountains, the Copper River and the Susitna basins, the n

No abstract available.

No abstract available.