Isotopic age determinations (40Ar/39Ar) and associated magnetic polarity stratigraphy for Casamayoran age fauna at Gran Barranca (Chubut, Argentina) indicate that the Barrancan "subage" of the Casamayoran South American Land Mammal "Age" is late Eocene, 18 to 20 million years younger than hitherto supposed. Correlations of the radioisotopically dated magnetic polarity stratigraphy at Gran Barra...

1. Geological Time: A Summary 2. Reconstruction and Relative Dating of Earth History 2.1. Early Ideas and Basic Principles 2.2. Uniformitarianism and Catastrophism 2.3. Geological Catastrophes and Events: Particular Historical Geological Phenomena 2.4. Rates of Geological Processes in Terms of Human Timescales 2.4.1. Earth Crust Movements 2.4.2. Plutonic and Volcanic Processes 2.4.3. Weathering...

Seismic interpretation has been traditionally based on reflections or amplitudes. However, amplitude alone can also disguise the true nature of subsurface geology and blur stratigraphic boundaries. In many cases important information is carried by singularities that are not necessarily associated to certain amplitude patterns. We present Hölder exponent (α) as a new seismic attribute which capt...

19th and 20th century stratigraphy often concerned itself primarily with classification and nomenclature, during what can be termed the heroic and codex ages of stratigraphy. In contrast, 21st century stratigraphy will fall within the post-modern age. In possession of agreed classification schemes, future stratigraphers will concentrate on (i) the reconstruction of earth environments and proces...

s Volume for the Krakow Congress (in Volumina Jurassica no. 4, 2006). The Working Group members were then asked in a two-point ballot: (1) That the Flodigarry section, Staffin Bay, Isle of Skye, Scotland be proposed as the GSSP section; (2) Either that the Pictonia flodigarriense Horizon or the Pictonia densicostata Horizon should be the primary marker for recognition and correlation of the bas...

Shallow Radar (SHARAD) on board NASA’s Mars Reconnaissance Orbiter has successfully detected tens of reflectors in the subsurface of the north polar layered deposits (NPLD) of Mars. Radar reflections are hypothesized to originate from the same material interfaces that result in visible layering. As a first step towards verifying this assumption, this study uses signal analyses and geometric com...

The goal of this project is to produce an open-source model that couples hydrodynamics (circulation and waves), sediment transport, and morphodynamics. The need and value for such a model has been well established by previous NOPP-supported planning efforts (Sherwood et al., 2000; 2002) and the feasibility of the proposed approach has been demonstrated by incorporation of sediment-transport and...

In this study, we apply advanced numerical optimization techniques to extend the work of Imhof and Sharma (2005, 2006) to integrate geological and geophysical data and infer the sedimentary parameters that produce a match to seismic data. In particular, we seek to match not just event timing (phase) but also reflection strength (amplitude). This inverse problem of quantitatively matching presen...

The article is devoted to Ivan Ivanovych Nikitin, the well-known Ukrainian scientist and researcher in field of stratigraphy, paleontology, Candidate Geological Mineralogical Sciences, senior Department Stratigraphy Paleontology Mesozoic deposits Institute Sciences National Academy Ukraine.

The Upper Triassic (Carnian–Norian) Martin Bridge Formation of northeastern Oregon, southeastern Washington, and western Idaho is characterized by rapidly shifting depositional processes within a tropical volcanic island arc setting. Martin Bridge sequences in the Hells Canyon and northern Wallowa Mountains document shallow-water peritidal evaporitic sediments that are succeeded by deeper and p...