Abstract This guidebook complements the field trips offered during the 42nd Annual Meeting of the GSA North-Central Section, held in Evansville, Indiana. Topics include analysis and correlation of Silurian depositional sequences across the Cincinnati Arch in Ohio, Kentucky, and Indiana; conodonts and Pennsylvanian stratigraphy in southwestern Indiana; relationships between tectonism, igneous activity, and fluorite mineralization within the Illinois-Kentucky Fluorite District; characteristics and origin of the highly eroded Pennsylvanian sandstones at the Garden of the Gods in Illinois; use of filled-fracture features as indicators of seismicity within the lower Wabash and Ohio River valleys; and hydrogeology of an abandoned mine site in Indiana, with applications to planning for disposal of coal-combustion products. Two chapters focus on the history of New Harmony, Indiana, which served as headquarters for the pioneering naturalists who worked to characterize and map this country's interior. Another chapter relates the history of Evansville to the availability and use of geologic materials, with discussions on the characteristics and origins of building stones, building techniques, and architectural styles. References to mining history, with respect to building stone, coal, and fluorite, are made throughout.

Abstract The purposes of this trip are to assist in interpreting the complexities of Pennsylvanian stratigraphy and sedimentation and to collect representative conodonts. The first stop is the West Franklin Limestone Member of the Shelburn Formation, which represents the Desmoinesian-Missourian boundary and the second is the Atokan Lead Creek Limestone Member of the Mansfield Formation. To help provide a general overview of the somewhat repetitive Pennsylvanian rock sequences in southwestern Indiana, we will visit two coal mines, each displaying several hundred feet of Desmoinesian rocks. We will be able to collect conodonts at all stops except Stop 3.

Abstract Minerals have been extracted from the Illinois-Kentucky Fluorite District for over 170 years. Theories concerning the inter-relationship between the fluorite mineralization, tectonism, and igneous activity will be discussed by several geologists during this field trip. The Columbia mine (vein deposit) will be visited in Kentucky, and the only mine currently producing fluorite in this district, the Hastie Limestone Quarry (strata-bound deposit), will be visited in Illinois. The mining history of this region will be explained at the American Fluorite Museum, where numerous mineral specimens can be examined. The Hicks Dome, a Permian crypto-volcanic feature (?) in Illinois, will also be discussed. The trip will conclude with a walking tour at the Garden of the Gods Recreational Area to view the Eagle Valley Syncline and Lower Pennsylvanian units.

Abstract This field trip features the visits and work of Maximilian, Prince of Wied; David Dale Owen; Charles Alexandre Lesueur; and other natural scientists who visited or lived in New Harmony, Indiana, USA. We also outline the history of this remarkable town and note items of geological and geographical interest seen in and around New Harmony, Indiana, including the Wabash River, Native American mounds, a garden-style cemetery containing the graves of prominent scientists, and historic stone structures.

Abstract Enhanced scrubber technology for coal-fired boilers, to be brought online at the Alcoa Warrick Operations Plant in Newburg, Indiana, USA, will generate increased volumes of coal-combustion products. This paper and field trip examine hydrogeological characteristics at the site of a management facility for coal-combustion products currently in development. An exposed highwall strip pit (Y-pit) on abandoned mine lands will be the site for coal-combustion product placement. Hydrogeological monitoring and characterization data for mined area spoils and unmined Paleozoic rocks will be reviewed in the field. Mine spoils at this site display horizontal hydraulic conductivities that range from 10 -3 to 10 -8 cm/s, and unmined bedrock varies from 10 -7 to 10 -8 cm/s. Groundwater at the B-2 site in shallow spoils near the Y-pit displays responses to precipitation events, and groundwater levels at the B-5 site in the unmined bedrock display Earth-tide responses. The Y-pit has variable hydrogeologic regimes along its length, including areas of flow-through and discharge. Groundwater discharge gradients increased markedly during periods of drought. Groundwater recharge gradients in the flow-through area decreased during drought conditions. Spoils groundwater is dominantly a highly mineralized water rich in calcium sulfate, and bedrock groundwater is highly mineralized water rich in sodium sulfate/chloride. Y-pit surface water most closely resembles spoils groundwater. Both the mine spoils and unmined bedrock groundwater samples have concentrations of arsenic that exceed the primary drinking water standard.

Abstract The lower Wabash and Ohio River valleys have experienced seismicity throughout geologic time. The rocks and sediments in southern Indiana, southern Illinois, and western Kentucky provide records of these past seismic events in the form of various types of filled fractures. In the field these features occur either as downward penetrating, surface-filled fractures created by tectonic deformation or seismicity, or as upward penetrating liquefaction features such as clastic dikes and sills created by strong earthquakes. The fractures are widespread and abundant in many places, and are usually seen in natural exposures such as stream banks and less commonly in man-made excavations. In contrast, their causative faults are rarely observed. Thus, compared to searching for faults, the study of filled fractures is a useful and relatively inexpensive technique for assessing the seismic history of a region. The fractures discussed are clearly of seismic origin on the basis of morphology, sediment characteristics, regional patterns, and proximity to known faults. Further research is needed to determine whether additional types of features, which we discuss and examine in the field, can also serve as paleoseismic indicators.

Abstract Evansville, Indiana, USA, grew up along a curve of the Ohio River. Ready access to natural resources including wood, coal, limestone, sandstone, shale, sand, gravel, and clay facilitated its growth. Development of lines of commerce; notably, the road network, steamboat traffic on the Ohio River, the Wabash and Erie Canal, and eventually railroads, expanded access to an ever wider array of materials, including a variety of building stones from North America and Europe. The history of source-area expansion is documented in the time-oriented array of buildings in Evansville and the materials preserved in them. We will illustrate that the availability of an ever-widening source of stone, building techniques, and architectural styles, from massive stones of ornate Victorian structures to the spare, thin cladding of modern buildings, can be used to elucidate the cultural attributes of this unique city. Stops include a number of downtown sites, including historic Victorian structures and more modern buildings with thin stone cladding, some of it bowing. We will also visit Reitz School, which is located above an old coal mine, and Oak Hill Cemetery, a classic garden-style cemetery located on a hilly outlier of loess.

Abstract New Harmony, Indiana, has an important place in the history of geology for North America. David Dale Owen, son of Robert Owen, who had attempted to establish a communal society in New Harmony, developed an impressive geological enterprise there. D.D. Owen's work included geological training at his New Harmony laboratories and the first geological mapping expeditions for many states and districts in the expanding United States. He served as the first state geologist for Indiana, a position also held by his brother, Richard. Several scientific notables, including William Maclure, Charles Lyell, Thomas Say, and others visited and studied natural history while based in New Harmony. The famous "Boatload of Knowledge" brought several artists, teachers, scientists, and other intellectuals to their new home in New Harmony, Indiana. Our trip to some of the original sites in this important town, including D.D. Owen's geological laboratories and Maclure's Working Men's Institute, will take us through the characteristic southwestern Indiana landscape of glacial-meltwater-lake plains, loess mantled bedrock uplands, and the Ohio and Wabash River valleys.

Abstract The Silurian rocks of the Cincinnati Arch in Ohio, Kentucky, and Indiana have been studied for nearly two centuries. Compilation of data from these studies, combined with detailed analysis of nearly 20 continuous drill cores and remeasuring and resampling of more than 60 major outcrops, is the basis for a high-resolution sequence stratigraphic framework. Seven depositional sequences are assigned on the basis of through-going unconformities, which mirror those already recognized in the early Llandovery to early Ludlow of the northern Appalachian Basin. Revision of the conodont biostratigraphy for the Cincinnati Arch has produced results that both agree and disagree with the other lines of data implemented in the sequence stratigraphic depositional model. Biostratigraphic correlations between southern Ohio and the Niagara Falls area are largely in agreement with correlations based on other lines of data, as are correlations between west-central and western Ohio, southeastern Indiana, and northern Kentucky. However, correlations between southern and west-central Ohio show major areas of disagreement. Preliminary whole rock carbonate carbon isotope analyses in western-central Ohio show patterns roughly comparable to those documented in the Niagara region, Gotland, and elsewhere. Chemostratigraphic data that might resolve inconsistencies in the correlations between southern and west-central Ohio were not yet available at the time of publication.