Westphalian B marine bands and their subsurface recognition using gamma-ray spectrometry
Loading...
Date
1997
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Yorkshire Geological Society
Abstract
Palaeogeographic reconstructions, marine band deposition and the variations of uranium enrichment in sediments
enable marine bands to be divided into four types: (1) Namurian marine bands, which represent marine anoxic black shale events,
with thick ammonoid acme phases that concentrate uranium; (2) Vanderbeckei marine bands have thin ammonoid acme zones and
abundant benthos, resulting from shallower water depths and poorly developed anoxic events with negligible uranium enrichment;
(3) Westphalian B/C marine bands are more marginal and have an abundance of land-derived plant fragments with adsorbed
uranium, as well as uranium entrapped within phosphatic tests of Lingula; (4) brackish water Lingula beds with abundant terrigenous
matter and negligible uranium response. This classification scheme provides a means of predicting the uranium response
of individual marine bands which is attributed primarily to the type and amount of organic matter, and the salinity of the waters
responsible for deposition. This approach allows marine bands to be recognized and identified in the subsurface from their gamma
ray and spectral gamma response, and together with palynological analysis allows the marine band to be placed more accurately
within the regional stratigraphic framework.
Description
Keywords
Citation
O’Mara, P. T., & Turner, B. R. (1997). Westphalian B marine bands and their subsurface recognition using gamma-ray spectrometry. Proceedings of the Yorkshire Geological Society, 51(4), 307-316.