Abstract This field guide focuses on key outcrops that highlight recent nomenclatorial changes of Early Silurian strata in western Ohio (e.g., Dayton Formation, Osgood Formation, Laurel Formation, Lewisburg Formation, Massie Formation, Euphemia Dolomite), as well as the Brassfield Formation and Springfield Dolomite. The field trip begins near the apex of the Cincinnati/Findlay Arch at a quarry in Ludlow Falls, Ohio, and ends at a more offshore position to the southeast, near Clifton, Ohio. Recent conodont biostratigraphic and δ 13 C carb chemostratigraphic data for many of those formations at the field trip localities clearly demonstrate coeval stratigraphic patterns present throughout western Ohio that were previously obscured due to prior inconsistent lithostratigraphic terminology and correlation. Those data also help to show important differences in stratigraphic patterns in western Ohio. Strata correlative to the Lee Creek Formation are recognized for the first time near the apex of the Cincinnati/Findlay Arch in western Ohio in West Milton, Ohio, and are tentatively identified as that formation. At the same locality the Dayton is shown to be completely absent, and the Osgood Formation overlies a thin unit tentatively identified as the Lee Creek Formation and underlying Brassfield Formation. The Springfield Dolomite at the Barrett Paving Materials Ludlow Quarry in Ludlow Falls, Ohio, contains trilobites of the Gravicalymene celebra Association, one of the most taxonomi-cally diverse and geographically widespread trilobite associations in the Silurian of North America. Pentamerid brachiopods occur with molts of Gravicalymene celebra in the Springfield there, suggesting an environmental complexity not seen elsewhere; pentamerids are not found in strata containing the Gravicalymene celebra Association in most other areas of the Midwest.

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Abstract Even before 1800, geological resources such as chert, iron, limestone, and coal were being utilized from the Pennsylvanian rocks of eastern Ohio and western Pennsylvania. These materials were of great interest to the early geologists of the region. This field trip discusses these products in the context of early grain milling, iron furnaces, and allied industries of Ohio and Pennsylvania in the late eighteenth and early nineteenth century, with a focus on two publicly accessible sites: McConnells Mill Park in western Pennsylvania, and Mill Creek Park in eastern Ohio. These parks contain publicly accessible gristmills and iron furnaces, and outcrops. We also provide new observations on cultural materials related to these industries, especially iron-furnace slag and millstones.

Abstract Even before 1800, geological resources such as chert, iron, limestone, and coal were being utilized from the Pennsylvanian rocks of eastern Ohio and western Pennsylvania. These materials were of great interest to the early geologists of the region. This field trip discusses these products in the context of early grain milling, iron furnaces, and allied industries of Ohio and Pennsylvania in the late eighteenth and early nineteenth century, with a focus on two publicly accessible sites: McConnells Mill Park in western Pennsylvania, and Mill Creek Park in eastern Ohio. These parks contain publicly accessible gristmills and iron furnaces, and outcrops. We also provide new observations on cultural materials related to these industries, especially iron-furnace slag and millstones.

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.