Publications

Raman spectroscopy is a powerful method for the determination of CO2 densities in fluid inclusions, especially for those with small size and/or low fluid density. The relationship between CO2 Fermi diad split (Δ, cm−1) and CO2 density (ρ, g/cm3) has been documented by several previous studies. However, significant discrepancies exist among these studies mainly because of inconsistent...

The surface exposure of the Paleocene Wilcox Group in northeast Texas varies in width from 9 to 27 mi along an arcuate outcrop that extends southwest approximately 156 mi from the Texas-Arkansas State line to 32° latitude. Parts of Bowie, Camp, Cass, Franklin, Henderson, Hopkins, Morris, Navarro, Rains, Titus, Van Zandt, and Wood Counties are included in this outcrop belt (Figure 1)...

The Wilcox Group of central Texas contains shallow (less than 500 ft) coal deposits that are mined for use in mine-mouth electric power generating plants. These coal deposits range in apparent rank from lignite to sub-bituminous (Pierce et al., 2011) and are similar in rank and composition to shallow coal deposits in the northeast and south Texas areas (Figure 1). The coal zones and...

This review of the lignite deposits of western Tennessee and the Jackson Purchase area in western Kentucky (Figure 1) is an updated report on part of the U.S. Geological Survey's National Coal Resource Assessment of the Gulf Coastal Plain Coal Province (see Ruppert et al., 2002; Hackley et al., 2006; Dennen, 2009; and other chapters of this publication). Lignite deposits of western...

The Wilcox Group of northeast Texas contains shallow (less than 500 ft) coal deposits that are mined for use in mine-mouth electric power generating plants. The coal deposits, which are lignite in apparent rank (Pierce et al., 2011), are separated from similar shallow coal deposits in the Sabine uplift area by the East Texas Basin (Figure 1). The coal zones and associated strata in the...

Three sides of the Canada Basin are bordered by high-standing, conjugate rift shoulders of the Chukchi Borderland, Alaska and Canada. The Alaska and Canada margins are mantled with thick, growth-faulted sediment prisms, and the Chukchi Borderland contains only a thin veneer of sediment. The rift-margin strata of Alaska and Canada reflect the tectonics and sediment dispersal systems of...

Tourmaline is a widespread mineral in the Mesoproterozoic Blackbird Co–Cu–Au–Bi–Y–REE district, Idaho, where it occurs in both mineralized zones and wallrocks. We report here major-element and B-isotope compositions of tourmaline from stratabound sulfide deposits and their metasedimentary wallrocks, from mineralized and barren pipes of tourmaline breccia, from late barren quartz veins...

The Bolsovian (Middle Pennsylvanian) Peach Orchard coal bed is one of the splint coals of the Central Appalachians. Splint coal is a name for the dull, inertinite-rich lithologies typical of coals of the region. The No. 3 Split was sampled at five locations in Magoffin County, Kentucky and analyzed for petrography and major and minor elements. The No. 3 Split coals contain semifusinite...

The National Coal Resource Assessment (NCRA) project of the U.S. Geological Survey (USGS) has assessed the quantity and quality of the nation's coal deposits that potentially could be mined during the next few decades. For eight years, geologic, geochemical, and resource information was collected and compiled for the five major coal-producing regions of the United States: the Appalachian...

No abstract available.

A common practice for characterizing uncertainty in coal resource assessments has been the itemization of tonnage at the mining unit level and the classification of such units according to distance to drilling holes. Distance criteria, such as those used in U.S. Geological Survey Circular 891, are still widely used for public disclosure. A major deficiency of distance methods is that...

Tourmaline occurs in diverse types of hydrothermal mineral deposits and can be used to constrain the nature and evolution of ore-forming fl uids. Because of its broad range in composition and retention of chemical and isotopic signatures, tourmaline may be the only robust recorder of original mineralizing processes in some deposits. Microtextures and in situ analysis of compositional and...