Characterization and Correlation of Carboniferous Marine Bands Using Inorganic Geochemistry

Michael A. Love, Andrew Racey, Roman Bobolecki, Nick Walsh

Marine bands are important marker horizons used in correlating Namurian-Westphalian sequences in the United Kingdom (UK) and elsewhere. Their specific identification, however, is frequently based mainly on the presence of certain index macrofossils and palynomorph assemblages which are more readily obtained in outcrops. Such fossil material, however, is not so easily and accurately obtained from boreholes thus rendering marine band identification and correlation far more difficult.

This paper presents the results of a study into the use of Inductively Coupled Plasma-Atomic Excitation Spectroscopy (ICP-AES) in the study of Carboniferous (Namurian) marine bands. Up to thirty elements (including the major oxides, trace and rare earth elements) are analyzed quantitatively for each sample studied in order to provide an overall geochemical signature for each marine band. Examples are taken from both the onshore and offshore United Kingdom. Onshore locations have been systematically sampled in order to assess internal variations of element concentrations within each marine band. Although such systematic sampling has not been possible in the offshore locations, the use of this technique as a means of discriminating individual marine bands is evaluated. Various computer rocessing techniques together with a statistical exploration of the ICP-AES data are also presented.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995