List of Plates and Figures


FIGURES

Figure 1  Physiographic map of the Union Furnace area
Figure 2  A portion of the Digital Shaded-Relief Map of Pennsylvania
Figure 3  Generalized stratigraphic column
Figure 4  Generalized cross section of the Ridge and Valley and Appalachian Plateau
Figure 5  Simple Bouger gravity map of Pennsylvania showing the trend of the Tyrone-Mt Union lineament
Figure 6  Trenton and deeper wells in Pennsylvania
Figure 7  Lithostratigraphic correlation diagram for uppermost Cambrian and Ordovician rocks in the central Appalachian basin
Figure 8  Late Ordovician paleogeography
Figure 9   Paleoceanography of Earth during the Late Ordovician
Figure 10  Ordovician stratigraphic column for central and western Pennsylvania
Figure 11  Ancient Appalachian tectonic subsidence history
Figure 12  The Deicke K-bentonite
Figure 13  Interpretation of carbonate facies in the Coburn through Loysburg Formations
Figure 14  Carbonate ramps
Figure 15  Modern homoclinal carbonate ramp environments
Figure 16  Landsat image of northern Yucatan, Mexico
Figure 17   Measured Trenton and Black River section along PA 453
Figure 18  Legend for symbols used in the stratigraphic diagrams
Figure 19  Hardgrounds exposed near Bimini
Figure 20  Effects of sea level variations on carbonate sedimentation, hardground formation, and the development of vertical sedimentary successions
Figure 21  Morphological classification of hardgrounds
Figure 22  Hardgrounds of the Hatter Formation
Figure 23  Undercut to pebbly hardgrounds in the Linden Hall Formation
Figure 24  Reworked hardground in the Linden Hall Formation
Figure 25  Nodular bedding in the Nealmont Formation
Figure 26  Generalized geologic map of the Altoona-Tyrone area
Figure 27  Cross section A-A’
Figure 28  Geologic map of the Tyrone-Union Furnace area
Figure 29  Orientation diagrams for structures in the Union Furnace area
Figure 30  Photographs of Union Furnace quarry
Figure 31  Photographs of Union Furnace quarry geologic structures
Figure 32  Arch Spring
Figure 33  Map of Tytoona Cave
Figure 34  Stalagmites and stalactites in Tytoona Cave
Figure 35  Soda straw stalactites in Tytoona Cave
Figure 36  Two views of Arch Spring
Figure 37  Entrance to Field Trip Cave along PA 453
Figure 38  Map of Field Trip Cave
Figure 39  Aerial photograph of Route 453, Union Furnace Quarry, and surrounding areas
Figure 40  Alternating dolostone and limestone in the Milroy Member (“Tiger Stripe”) of the Loysburg Formation
Figure 41  Subtidal peritidal facies in the Loysburg Formation
Figure 42  Wavy, flaser, and lenticular bedding, and mudcracks in the Loysburg Formation
Figure 43  Microbially laminated mudstones in the Loysburg Formation
Figure 44  Chert in the Loysburg Formation
Figure 45  Vertical facies successions in the Hatter Formation
Figure 46  Lagoonal carbonate facies in the Hatter Formation
Figure 47  Fossils in the lagoonal facies of the Hatter Formation
Figure 48  Landsat images of Shark Bay, Australia and Yucatan, Mexico
Figure 49  Grainstones in the Hatter Formation
Figure 50  Bioturbated, dark, organic-rich mudstone in the Snyder Formation
Figure 51  Vertical facies successions in the Snyder Formation
Figure 52  Oolitic grainstones in the Snyder Formation
Figure 53  Mixed grainstones in the Snyder Formation
Figure 54  Hardgrounds in the Snyder Formation
Figure 55  Bryozoans in the Snyder Formation
Figure 56  Vertical succession of sedimentary features in the Linden Hall Formation
Figure 57  Hardgrounds in the Linden Hall Formation
Figure 58  Photomicrographs of the Linden Hall Formation
Figure 59  Vertical succession of sedimentary features in the Nealmont Formation and lowermost Salona Formation
Figure 60  Photographs of the Nealmont Formation
Figure 61  Photographs of the Nealmont Formation
Figure 62  Photomicrographs of the lower Nealmont Formation
Figure 63  Photographs of the Salona Formation
Figure 64  Idealized Salona Formation cycles
Figure 65  Photographs of the Coburn Formation

PLATES

Plate 1  Panoramic view of “west” quarry highwall (1996)
Plate 2  Geological map of Route 453 road-cut 27