Where does the time go? Assessing the chronostratigraphic fidelity of sedimentary geological outcrops in the Pliocene–Pleistocene Red Crag Formation, eastern England
| Autor: | Anthony P. Shillito, Neil S. Davies, William J. McMahon |
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| Přispěvatelé: | Davies, NS [0000-0002-0910-8283], Shillito, AP [0000-0002-4588-1804], Apollo - University of Cambridge Repository |
| Rok vydání: | 2019 |
| Předmět: |
Regional geology
Earth history 010504 meteorology & atmospheric sciences Pleistocene Outcrop 37 Earth Sciences 3705 Geology Geology 3709 Physical Geography and Environmental Geoscience 010502 geochemistry & geophysics 01 natural sciences Deposition (geology) Sedimentary depositional environment Paleontology Sedimentary rock 0105 earth and related environmental sciences Small window |
| Zdroj: | Journal of the Geological Society. 176:1154-1168 |
| ISSN: | 2041-479X 0016-7649 |
| Popis: | It is widely understood that Earth9s stratigraphic record is an incomplete record of time, but the implications that this has for interpreting sedimentary outcrop have received little attention. Here we consider how time is preserved at outcrop using the Neogene–Quaternary Red Crag Formation, England. The Red Crag Formation hosts sedimentological and ichnological proxies that can be used to assess the time taken to accumulate outcrop expressions of strata, as ancient depositional environments fluctuated between states of deposition, erosion and stasis. We use these to estimate how much time is preserved at outcrop scale and find that every outcrop provides only a vanishingly small window onto unanchored weeks to months within the 600–800 kyr of ‘Crag-time’. Much of the apparently missing time may be accounted for by the parts of the formation at subcrop, rather than outcrop: stratigraphic time has not been lost, but is hidden. The time-completeness of the Red Crag Formation at outcrop appears analogous to that recorded in much older rock units, implying that direct comparison between strata of all ages is valid and that perceived stratigraphic incompleteness is an inconsequential barrier to viewing the outcrop sedimentary-stratigraphic record as a truthful chronicle of Earth history. Supplementary material: Further details of the regional geology and specific information on outcrops are available at https://doi.org/10.6084/m9.figshare.c.4561001 |
| Databáze: | OpenAIRE |
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