Abstract Burning and evolving for over 50 years, the anthracite coal fire in Centralia, Pennsylvania, has provided researchers with an ideal environment to study how shallow coal fires affect surface vegetation, nutrients and soil, landscape subsidence, organisms, fire migration, as well as human health. Ten years ago, surface temperatures from some gas exhaust vents were measured to be between 456° and 540 °C, and the fire was recorded to be moving rapidly at a rate of 20–22 m/yr. However, the fire has changed considerably since that time. Today, the average annual temperature of surface exhaust vents is ~65 °C, and its rate of movement is nearly unperceivable. In light of the changing parameters of the fire, Centralia continues to provide an interesting environment in which to study the effects of a subsurface anthracite coal fire on the landscape. This field trip will examine the geologic structure of the region, the Buck Mountain coal succession, the geomorphic features produced by the fire, the environmental consequences related to the removal of natural resources like coal, how a government responds to regional environmental disasters like coal fires, and the legacy of a coal fire on a region. Over the past decade, this fire and its influence on the landscape have changed considerably. However, there are still many interesting things to learn from this fire and the surrounding region.

Abstract Centralia is in Pennsylvania’s western middle anthracite field, a large synclinorium in Columbia and Schuylkill Counties. Centralia residents set fire to a landfill at the edge of town in 1962, thereby igniting the Buck Mountain coal bed. Laurel Run is in Pennsylvania’s northern anthracite field, on the northwest-dipping limb of the Wyoming Valley syncline. In 1915, a miner’s abandoned carbide lamp started a fire at Laurel Run, igniting the Red Ash, Top Red Ash, and Bottom Ross coal beds. The Centralia and Laurel Run fires are burning out of control. Subsidence and the venting of toxic gases have destroyed large sections of each community. Because the Centralia fire started in the hinge zone of an anticline separating two synclines in the Western Middle Field, it spread in four directions. The Laurel Run fire occurred on one limb of a syncline, limiting its spread to two directions. At Centralia, the steeper-dipping beds permitted the fire to reach a greater depth more rapidly than at Laurel Run. In addition, the point of origin and steeper dip at Centralia make this fire more difficult to control, even though only one coal bed is burning. A historical and sociological comparison of both communities shows that the people of Laurel Run had greater access to political power and more experience as a community in dealing with crises. Laurel Run secured more government support in combating the fire than Centralia did and so emerged from the fire as a more socially intact community. The present state of each fire further underscores how different geologic settings and social conditions can lead to different outcomes.

Abstract The “sedimentary cover” refers to the stratified rocks of youngest Proterozoic and Phanerozoic age that rest upon the largely crystalline basement rocks of the continental interior. The early chapters of the volume present data and interpretations of the geophysics of the craton and summarize, with sequential maps, the tectonic evolution of the craton. The main body of the text and accompanying plates and figures present the stratigraphy, structural history, and economic geology of specific sedimentary basins (e.g., Appalachian basin) and regions (e.g., Rocky Mountains). The volume concludes with a summary chapter in which the currently popular theories of cratonal tectonics are discussed and the unresolved questions are identified.

Abstract The thickest and most laterally continuous upper Carboniferous molasse in the central Appalachians is located in the Southern Anthracite Field of northeastern Pennsylvania. Substantial deposits extend throughout northeastern Pennsylvania where >90% of the total anthracite (original reserves) in the United States and the thickest coal beds of the eastern United States are located. The abundance of and demand for this resource allowed the region to prosper in the nineteenth and twentieth centuries. In Pottsville, Pennsylvania, the exposed Upper Mississippian to Middle Pennsylvanian molasse reveals a progressive evolution from a semiarid alluvial plain to a semihumid alluvial plain to a humid alluvial plain. The anthracite beds occur and thicken with increased humid conditions. The progression is also exposed in Tamaqua, Pennsylvania, where convenient access to the underlying Lower Mississippian strata is available, thus providing a section of all Carboniferous formations in the region. Finally, in Lansford, Pennsylvania, a renovated deep anthracite mine illustrates the historical methods and working conditions that existed to extract the valuable resource and allow the region to flourish and fuel the Industrial Revolution.

The Upper Jurassic-Lower Cretaceous Mist Mountain Formation in the southeastern Canadian Cordillera is a nonmarine succession up to 670 m thick that includes as many as 15 major seams of high volatile bituminous to semi-anthracite coal. Coals at the base of the formation were deposited in coastal and delta plain environments, whereas those of the upper part are interpreted as upper delta plain and alluvial plain deposits. The coal seams are thicker, more abundant, and laterally less continuous in the upper part of the formation. The geometry of the coal seams is influenced by the presence of adjacent channels that have locally thinned or washed out some seams. The effect of differential compaction on coal seam geometry is variable; some seams thin over paleo-channels, whereas others are thicker and/or contain fewer partings. The ash content of most coals shows no predictable lateral or vertical variation that can be related to the overall sedimentology, nor is there a correlation between seam thickness and ash content. The sulfur content of all seams is low (<1 percent), suggesting the absence of marine influence during peat accumulation. There is a general increase in vitrinite and a decrease in inertinite and semi-fusinite from the base to the top of the formation, which may reflect a greater contribution of herbs to coals formed from coastal marsh-swamp complexes at the base. Variations in roof conditions in underground mines are related to the structural fabric of the coal measures, which in turn reflects the kinematics and dynamics of tectonic deformation and roof rock lithology. In the Vicary Creek Mine, the roof rock comprises two lithofacies: a thin-bedded, very fine grained, carbonaceous sandstone lithofacies interpreted as distal crevasse splay deposits, and a thick-bedded sandstone lithofacies interpreted as proximal splay deposits. The thin-bedded lithofacies includes carbonaceous partings that were preferred horizons for intrastratal slip along which cohesion of the roof rock has been lost. The thick-bedded sandstone lithofacies is well jointed, leading to a blocky roof rock that localized intrastratal slip within the underlying coal seam. In the Balmer North and Five Panel Mines, the roof rock is composed of carbonaceous siltstone and very fine grained sandstone interpreted as crevasse splay and overbank deposits. During flexural-slip folding, slip was localized along carbonaceous partings that have destroyed the cohesion between successive beds in the roof rock. The intersections of slickensided bedding surfaces and major shear and extension fracture systems have resulted in unstable roof rock, particularly in rooms and roadways developed parallel to their intersection.