Sequencing, Scaling and Correlation of Stratigraphic Events

摘要

The RASC computer program for ranking and scaling of stratigraphic events was developed between 1978 and 1985. It has been available unaltered as version 12 since 1985, and new methodology justified an update commenced in 1994. This paper discusses revised method of scaling stratigraphic events. New results are compared with previous results for a mid-Cretaceous optimum sequence of 87 dinoilagellate, foraminiferal and a log event in 29 wells, northern North Sea and offshore mid-Norway. The improved method (RASC, version 15) yields better definition of clusters of biostratigraphic events, and more sharply defined intercluster distances (breaks) coinciding with hiatusses that can be interpreted in terms of northwestern European sequence stratigraphy. In general, the new scaling procedure is more robust to diminished frequencies of co-occurrences of fossil events in the same wells.