To: Brumar89 who wrote (968376 ) 9/29/2016 10:30:49 AM From: Wharf Rat Respond to of 1573924 "To the contrary, the real experts, i.e. those who specialize in earth layers, see nothing there. The Anthropocene serves as a career promoter for scientists in outside fields.” Perhaps the author is looking in the wrong layers. A stratigraphical basis for the Anthropocene? Colin N. Waters 1 , * , Jan A. Zalasiewicz 2 , Mark Williams 2 , Michael A. Ellis 1 and Andrea M. Snelling 3 + Author Affiliations 1Environmental Science Centre, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK2Department of Geology, University of Leicester, Leicester LE 1 7RH, UK3NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK ? *Corresponding author (e-mail: cnw@bgs.ac.uk ) Next Section Abstrac tRecognition of intimate feedback mechanisms linking changes across the atmosphere, biosphere, geosphere and hydrosphere demonstrates the pervasive nature of humankind's influence, perhaps to the point that we have fashioned a new geological epoch, the Anthropocene. To what extent will these changes be evident as long-lasting signatures in the geological record? To establish the Anthropocene as a formal chronostratigraphical unit it is necessary to consider a spectrum of indicators of anthropogenically induced environmental change, and to determine how these show as stratigraphic signals that can be used to characterize an Anthropocene unit and to recognize its base. It is important to consider these signals against a context of Holocene and earlier stratigraphic patterns. Here we review the parameters used by stratigraphers to identify chronostratigraphical units and how these could apply to the definition of the Anthropocene. The onset of the range of signatures is diachronous, although many show maximum signatures which post-date 1945, leading to the suggestion that this date may be a suitable age for the start of the Anthropocene. The ‘Anthropocene’ is in many respects a novel potential geological unit. Stratigraphy, which deals with the classification of geological time (geochronology) and material time-rock units (chronostratigraphy), has historically defined geological units based upon significant, but temporally distant, events. These events are typically, although not exclusively, associated with major changes in the fossil contents of rocks below and above a particular horizon, and therefore with the temporal distribution of life forms. It was only following such observations that new stratigraphical units were proposed and ultimately defined. For example, J. Phillips used the major mass extinction at the end of the Permian in 1840 to recognize the beginning of both the Triassic Period and of the Mesozoic Era. The ultimate definition of the base of the Triassic, however, was accomplished only in 2001, when the Global Stratotype Section and Point (GSSP) was taken at the base of a specific bed in a section in Meishan, China, coinciding with the lowest occurrence of the primary marker, the conodont Hindeodus parvus ( Yin et al. 2001 ). In contrast, the Anthropocene was proposed as a term ( Crutzen & Stoermer 2000 ) before any consideration of the nature of the signature of this new stratigraphical unit was given. For the first time in geological history, humanity has been able to observe and be part of the processes that potentially may signal such a change from the preceding to succeeding epoch. What are the key ‘events’ over the last decades to millennia that have the potential to leave a recognizable record in sediments/ice that could be used to define the base of the Anthropocene? The options cover a diverse range of geoscientific fields and need not be restricted to the biostratigraphical tools typically used throughout much of the geological column to define chronostratigraphical units. Potential stratigraphical tools and techniques that may be used to define the base of the Anthropocene include the following (Fig. 1 ): Appearance and increased abundance of anthropogenic deposits: artificial anthropogenic deposits; anthropogenic soils (anthrosols); novel minerals and mineraloids; anthropogenic subsurface structures (‘trace fossils’); anthropogenic modification of terrestrial and marine sedimentary systems. Biotic turnover: megafauna; reef ecosystems; microflora; microfauna. Geochemical: evidence preserved in the cryosphere; records in speleothems; organic and inorganic contributions to sediments. Climate change: ocean geochemistry; oceanic biodiversity; continental to ocean sediment flux; sea-level change. Catastrophic events: radiogenic spikes from nuclear bomb tests/accidents; volcanic eruption; meteorite/asteroid (bolide) impact.sp.lyellcollection.org