Crowns of four crinoid species, Talarocrinus planus Weller, 1920, Phacelocrinus longidactylus (McChesney, 1860), Ampelocrinus mundus? Kirk, 1942, and Phanocrinus maniformis (Yandell and Shumard, 1847) are reported from the limestones of the Wymps Gap Member of the Greenbrier Formation in northern West Virginia. Collectively these species indicate an early Chesterian age for the Wymps Gap Member...

3D spatial data model and modelling are the core of 3D GIS theory and applications. For this reason, a data model based on Quasi Tri-Prism Volume (QTPV) has been presented in this paper. The QTPV definition and its special cases due to vertices of QTPV may be superposition have been considered. The proposed model is composed of five primitives and six objects. The primitives consist of vertex, ...

Gale Crater, the Mars Science Laboratory (MSL) landing site, contains a central mound, named Aeolis Mons (informally Mount Sharp) that preserves 5 km of sedimentary stratigraphy. Formation scenarios include (1) complete filling of Gale Crater followed by partial sediment removal or (2) building of a central deposit with morphology controlled by slope winds and only incomplete sedimentary fill. ...

Geologic observations of the Chinese Tian Shan foreland reveal active, contractional deformation along the entire margin. To quantify the amount of shortening and understand the structural style, we mapped the stratigraphy and structure of four folds expressed at the western end of the foreland, north of Kashi. In this region, upper Tertiary through Quaternary sediments are conformable, but an ...

Several relatively thin tectono-metamorphic slices have been recognized in the Cycladic eclogite– blueschist belt, through detailed studies on Ios, Sifnos, Syros, and Tinos. A sequence of distinct metamorphic mineral growth events has been documented. These recur in each tectonic slice, although individual slices are dominated by different events. To constrain the timing of these processes, the...

Many versions of the history of Americanist archaeology suggest there was a "stratigraphic revolution" during the second decade of the twentieth century—the implication being that prior to about 1915 most archaeologists did not excavate stratigraphically. However, articles and reports published during the late nineteenth century and first decade of the twentieth century indicate clearly that ma...

We compared the stratigraphy of sediment cores that span the last 13,000 yrs from three sites in the main basin of Lake Titicaca, Boliva/Peru as indicators of regional paleoclimate. The cores show similar patterns of change after ~6,400 calendar yrs before present (cal yr BP) but differ before that time. Site NE98-PC2, which is near the Rio Illave and its delta, shows differences in diatom spec...

[1] Stratigraphy preserved in alluvial basins holds important information for reconstructing past environmental conditions via inversion methodologies. In this paper we explore, through the use of physical and numerical experiments, the forward problem, that is, we quantify how the probabilistic structure of the processes that govern the evolution of depositional systems relates to the probabil...

[1] We present glaciological and climatological characteristics of Hercules Dome, Antarctica (86 S, 105 W), which demonstrate its potential as a deep ice core site. Annual layering in dD ratios from a 72 m ice core collected by the US-ITASE 2002 traverse indicate accumulation rates of 0.16–0.20 m/yr ice equivalent over the last 300 years. Age control from stratigraphy seen in the radio-echo sou...

The Campanian Ignimbrite (CI) eruption, dated by 40Ar/39Ar and various stratigraphic methods to ca. 39,000 cal BP, generated a massive ash plume from its source in southern Italy across Southeastern and Eastern Europe. At the Kostenki-Borshchevo open-air sites on the Middle Don River in Russia, Upper Paleolithic artifact assemblages are buried below, within, and above the CI tephra (which is re...