Early Ordovician trilobite biofacies in the Argentine Cordillera Oriental, Southwestern Gondwana: Paleoecologic and Paleogeographci significance

WAISFELD, B.G.

Las Vegas

Congreso; 7th International Symposium on the Ordovician System; 1995

Early Ordovician trilobite dominated associations are conspicuous in the Acoite and Sepulturas Formations, Cordillera Oriental, Northwestern of Argentina.Dense sampling resulted in a precise assemblage of matrerial containing about 3000 trilobite specimens in addition to hundreds of brachipods, bivalves, gastropods, etc.The purpose of this paper is to document composition and distribution of the trilobite biofacies in the Argentine Cordillera Oriental. Biofacies are established as objective entities that might be used for comparisons with similar entities in other gondwanic regions from paleoecological and paleobiogeographical points of view. The study is still in progress but preliminary results are herein presented. Some taxonomic assignments of trilobites within biofacies are preliminary New taxa are left in open nomenclature and will be the subject of subsequent papers.