Publications
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Loamy, two-storied soils on the outwash plains of southwestern lower Michigan: Pedoturbation of loess with the underlying sand
Soils on many of the outwash plains in southwestern Michigan have loamy upper profiles, despite being underlain by sand-textured outwash. The origin of this upper, loamy material has long been unknown. The purpose of this study is to analyze the spatio-textural characteristics of these loamy-textured sediments to ascertain their origin(s). The textural curves of this material have distinct bimodal
Authors
Michael D. Luehmann, Brad G. Peter, Christopher B. Connallon, Randall J. Schaetzl, Samuel J. Smidt, Wei Liu, Kevin A. Kincare, Toni A. Walkowiak, Elin Thorlund, Marie S. Holler
Petrology and tectonic history of the Green Bay Schist, Portmore, St. Catherine Parish, Jamaica
There are three occurrences of medium- to high-grade metamorphic rocks in Jamaica: amphibolite facies Westphalia Schist, blueschist/greenschist facies Mt. Hibernia Schist, and the hitherto poorly characterized amphibolite facies Green Bay Schist. New trace element data and thermodynamic calculations show that Green Bay Schist is closely related to Westphalia Schist. The protoliths for both are ver
Authors
Richard N. Abbott, David P. West, Betsy R. Bandy, Ryan J. McAleer
Awell-preserved conodont fauna from the Pennsylvanian Excello Shale of Iowa, U. S. A.
A superbly preserved discrete element conodont fauna has been recovered from carbonate concretions from the upper Desmoinesian (Pennsylvanian) Excello Shale at two localities in south-central Iowa. The multielement apparatuses for Gondolella wardlawi (new species), Idiognathodus acutus, Idioprioniodus conjunctus, and Neognathodus roundyi are reconstructed. Rare specimens of Idiognathodus tuberis (
Authors
Merlynd K. Nestell, Bruce R. Wardlaw, John P. Pope
Geologic context of large karst springs and caves in the Ozark National Scenic Riverways, Missouri
The ONSR is a karst park, containing many springs and caves. The “jewels” of the park are large springs, several of first magnitude, that contribute significantly to the flow and water quality of the Current River and its tributaries. Completion of 1:24,000-scale geologic mapping of the park and surrounding river basin, along with synthesis of published hydrologic data, allows us to examine the sp
Authors
David J. Weary, Randall C. Orndorff
Geology and geomorphology of the Carolina Sandhills, Chesterfield County, South Carolina
This two-day field trip focuses on the geology and geomorphology of the Carolina Sandhills in Chesterfield County, South Carolina. This area is located in the updip portion of the U.S. Atlantic Coastal Plain province, supports an ecosystem of longleaf pine (Pinus palustris) and wiregrass (Aristida stricta), and contains three major geologic map units: (1) An ~60–120-m-thick unit of weakly consolid
Authors
Christopher S. Swezey, Bradley A. Fitzwater, G. Richard Whittecar
Geology of the Mount Rogers area, revisited: Evidence of Neoproterozoic continental rifting, glaciation, and the opening and closing of the Iapetus ocean, Blue Ridge, VA–NC–TN
Recent field and geochronological studies in eight 7.5-minute quadrangles near Mount Rogers in Virginia, North Carolina and Tennessee recognize important stratigraphic and structural relationships for the Neoproterozoic Mount Rogers and Konnarock formations, the northeast end of the Mountain City window, the separation of Mesoproterozoic rocks of the Blue Ridge into three age groups, and timing an
Authors
Arthur J. Merschat, C. Scott Southworth, Christopher S. Holm-Denoma, Ryan J. McAleer
Structural geometry of the Valley and Ridge and Plateaus provinces
The Valley and Ridge physiographic province comprises
the area between the Blue Ridge province on the east and the
Appalachian Plateau province on the west. The province consists
of Paleozoic carbonate and clastic rocks that were folded and
thrust faulted during the Alleghanian orogeny. The Appalachian Plateau
province consists of mostly flat lying to gently dipping upper
Paleozoic rocks, with the
Authors
Mark A. Evans, Randall C. Orndorff, William S. Henika
Gondolellid conodonts and depositional setting of the Phosphoria Formation
The Phosphoria Formation and related rocks were deposited over an 8.9 m.y. interval beginning approximately 274.0Ma and ending approximately 265.1Ma. The Meade Peak Phosphatic Shale Member was deposited in southeastern Idaho and adjacent Wyoming over 5.4 m.y. from approximately 273.2 to 268.6 Ma. The Retort Phosphatic Shale Member was deposited in southwestern Montana and west-central Wyoming over
Authors
Bruce R. Wardlaw
Life on the edge in eastern Alaska: Basal Ordovician(Tremadocian), platform-margin faunas of the Jones Ridge Formation
As the most fossiliferous and least deformed succession of unequivocally Laurentian lower Paleozoic strata in Alaska, the Jones Ridge Limestone has provided critical data for numerous stratigraphic studies (e. g. Palmer 1968; Harris et al. 1995; Dumoulin et al. 2002; Dumoulin and Harris 2012) focused on the Cambrian and Ordovician of northwestern North America/northeastern Laurentia (Figure 1). Th
Authors
J. F. Taylor, T. J. Allen, John E. Repetski, J. V. Strauss, S. J. Irwin
The cost of karst subsidence and sinkhole collapse in the United States compared with other natural hazards
Rocks with potential for karst formation are found in all 50 states. Damage due to karst subsidence and sinkhole collapse is a natural hazard of national scope. Repair of damage to buildings, highways, and other infrastructure represents a significant national cost. Sparse and incomplete data show that the average cost of karst-related damages in the United States over the last 15 years is estimat
Authors
David J. Weary
An apparatus reconstruction of the conodont Caenodontus serrulatus Behnken 1975
The conodont species Caenodontus serrulatus Behnken is a rare coniform element first described in 1975 from Guadalupian strata exposed in the Guadalupe and Delaware Mountains of West Texas. Because it is rare, coniform, and occurs long after most coniform elements supposedly disappeared, it has been hauntingly mysterious. Based on new material containing a varied assemblage of coniform elements re
Authors
Merlynd K. Nestell, Bruce R. Wardlaw