THE MIDDLE CAMBRIAN OF SCANDINAVIA – AGNOSTOIDS AND GLOBAL CORRELATIONS

Many agnostoids are useful tools for intercontinental correlations of Cambrian strata. Westergård (1946) established a high-resolution biostratigraphy for the middle Cambrian of Scandinavia based on agnostoids, although he neither described the zones in detail, nor defined the zonal boundaries. Since his 1946 monograph, agnostoid trilobites have been used in biostratigraphy and correlations at an accelerating rate. There is now sufficient data available for a global agnostoid zonation of middle Cambrian successions, the base of each zone defined by the first appearance of a selected, geographically widespread species, and the top by the base of the succeeding zone (e.g., Peng & Robison 2000). Recent studies on the Almbacken drill core from southern Sweden show that the global agnostoid zonation proposed by Peng & Robison (2000) can be applied also to Scandinavian strata. Two additional drillings through the middle–upper Cambrian of Sweden are planned for 2004 to further refine the biostratigraphy and to study the faunal turnover around the middle–upper Cambrian boundary.