ABSTRACT

Rock-forming buildups of larger foraminifera, while not unknown in Louisiana, are rare, and are less common in the Gulf Coast than in Eocene strata from the Pyrenean and Caribbean regions. In strata from the Upper Wilcox Group (lower Eocene) in Pointe Coupee Parish, Louisiana, we have identified a thin, very rich faunal deposit, or bank, made up almost exclusively of the tests of the larger foraminifera species, Pseudophragmina (Proporocyclina) zaragosensis. This is the first report of P. (P.) zaragosensis from the Wilcox Group of Louisiana. The bank fauna colonized the sandy sea floor on the continental shelf, flourished briefly, and then gradually declined, probably in response to increasing water depth, caused either by compaction-induced subsidence, a local or regional rise in relative sea level or both. This bank indicates that during late Wilcox time, warm shallow continental shelf conditions prevailed in this region.