—Marshall (1995) used the distribution of the endpoints of 50% range extensions added to the stratigraphic ranges of individual taxa to bracket the position of an extinction boundary. Here we describe two improvements to Marshall’s method. First, we show that more precise estimates of the position of such a boundary may be obtained using range extensions with confidence levels of less than 50% ...

There has been recent debate over stratigraphic markers used to demarcate the Anthropocene from the Holocene Epoch. However, many of the proposed markers are found only in limited areas of the world or do not reflect human impacts on the environment. Here we show that spheroidal carbonaceous particles (SCPs), a distinct form of black carbon produced from burning fossil fuels in energy productio...

The zonal scheme of the Givetian-Frasnian boundary interval in Timan-Northern Urals region was detailed according to higher plants spores. Palynological zones were correlated with faunal, including conodont — orthostratigraphic group Devonian. correlation identified critical boundaries development plant communities divisions’ borders International Stratigraphic Scale series and stages, establis...

Biostratigraphic data provided by the sections of the Caravaca–Cehegı́n region, SE Spain, have contributed decisively to the lively debate that has taken place in recent years concerning the Berriasian/Valanginian boundary. This work presents the results from new integrated stratigraphic analyses of these sections, based on the distribution of ammonites, calpionellids and calcareous nannofossils...

The recent proliferation of stratigraphic studies of delta 13C variation in carbonates and organic C in later Neoproterozoic and basal Cambrian successions (approximately 850-530 Ma) indicates a strong oscillating trend in the C-isotopic composition of surface seawater. Alone, this trend does not adequately characterize discrete intervals in Neoproterozoic time. However, integrated with the vec...

The application of geological controls in orebody evaluation and modelling is critical. Stratigraphic orebodies require more accurate location in space and better seam boundary definition. This is achieved by either modelling boundary surfaces of the orebodies or their thickness at specific points in 3D space. Structurally deformed stratigraphic deposits pose a very special problem in variograp...

The surface area of Venus ( 460 10 km) is 90% of that of the Earth. Using Magellan radar image and altimetry data, supplemented by Venera-15/16 radar images, we compiled a global geologic map of Venus at a scale of 1:10 M. We outline the history of geological mapping of the Earth and planets to illustrate the importance of utilizing the dual stratigraphic classification approach to geological m...

Smith et al. (2003, hereafter referred to as Smith et al.) present seven new isotopic ages from the Green River Formation in the greater Green River Basin. These data provide welcome new information in the ongoing effort to develop a coherent and reliable geochronological framework for this large and stratigraphically complex basin. Several of their main conclusions are based on a revised age e...