Not logged in
PANGAEA.
Data Publisher for Earth & Environmental Science

Jenkyns, Hugh C; Weedon, Graham P (2013): Chemostratigraphy (CaCO3, TOC, d13Corg) of Sinemurian black shales. PANGAEA, https://doi.org/10.1594/PANGAEA.812220, Supplement to: Jenkyns, HC; Weedon, GP (2013): Chemostratigraphy (CaCO3, TOC, d13Corg) of Sinemurian (Lower Jurassic) black shales from the Wessex Basin, Dorset and palaeoenvironmental implications. Newsletters on Stratigraphy, 46(1), 1-21, https://doi.org/10.1127/0078-0421/2013/0029

Always quote above citation when using data! You can download the citation in several formats below.

RIS CitationBibTeX CitationShow MapGoogle Earth

Abstract:
The Shales-with-'Beef' and Black Ven Marls of the Charmouth Mudstone Formation (Sinemurian) exposed on the Dorset Coast in southern England (Wessex Basin) show stratigraphic variation in carbonate, organic carbon and organic-carbon isotopes. Little environmental significance is attached to the variation of carbonate except in the case of the tabular and nodular limestones interrupting the sequence that probably record stratigraphic condensation and/or sedimentary stillstands that, in an extreme case, were accompanied by sea-floor erosion to produce the bored and encrusted 'Coinstone'. Relatively high total organiccarbon (TOC) contents are present in the laminated mudstones of the lower turneri Zone (upper brooki and lower birch Subzones) and the obtusum Zone (obtusum and stellare Subzones). Basin stratification related to fresh-water influx was the most likely aid to deoxygenation and enhanced preservation of organic matter. The organic-carbon isotope curve (d13Corg), which shows positive excursions in the upper turneri Zone (upper birchi Subzone) and highest obtusum - raricostatum Zones (highest stellare Subzone, densinodulum and lower raricostatoides Subzones), does not correlate with the TOC stratigraphy and was clearly not controlled by local patterns of organic-matter burial. Long-term (hundreds-of-thousands of years) variations in the carbon-isotope (d13Corg) curve are interpreted as reflecting changing seawater isotopic composition and, in the case of the stratigraphically higher interval, may be related to marine organic-carbon burial on the margins of the proto-Atlantic, as exemplified by the Lusitanian Basin in Portugal. Correlation of the carbon-isotope profile with putative sea-level curves is problematic in detail, although significant local transgressive pulses in the turneri and late raricostatum Zones are approximately coincident with positive d13Corg excursions.
Coverage:
Latitude: 50.731700 * Longitude: -2.897020
Minimum SECTION, height: 0.1 m * Maximum SECTION, height: 66.6 m
Event(s):
Dorset * Latitude: 50.731700 * Longitude: -2.897020 * Location: England * Device: Sampling by hand (HAND)
Comment:
Black Ven Marls - samples below Stonebarrow = BVM+206 to BVM-156, below Black Ven = BVM-157 to SWB0. Note gap in sampling between BVM-247 and SWB+38 treated as 10 cm.
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethodComment
1Sample code/labelSample labelJenkyns, Hugh C
2SECTION, heightSectionmGeocode
3Calcium carbonateCaCO3%Jenkyns, Hugh C
4Carbon, organic, totalTOC%Jenkyns, Hugh C
5delta 13C, organic carbond13C Corgper mil PDBJenkyns, Hugh C
6BedBedJenkyns, Hugh CLamg's bed nos
7StratigraphyStratigraphyJenkyns, Hugh CBed names and biostratigraphy
Size:
2311 data points

Download Data

Download dataset as tab-delimited text (use the following character encoding: )

View dataset as HTML (shows only first 2000 rows)