A turritelline gastropod-dominated limestone from the Pliocene of northern Chile: Paleoenvironmental and paleoceanographic implications.

Turritelline gastropod-dominated assemblages (TDAs) are common in siliciclastic facies from the mid-Cretaceous to the Recent, but their distribution in carbonate facies has been thought to be limited to the Cretaceous and Paleogene, except for "cool-water" carbonates from the Miocene of Australia. This paper describes a TDA in a Pliocene limestone in northern Chile, the only known Neogene TDA limestone from outside Australia. This Chilean TDA probably formed in conditions of relative low temperatures and high productivity, and thus appears to support the hypothesis that TDAs largely disappeared from warm waters after the Oligocene. It is also possible, however, that it formed in conditions of warmer temperatures associated with upwelling during the Early Pliocene warm interval. • A turritelline gastropod-dominated assemblage from Chile is Early or Late Pliocene. • The limestone assemblage is a rarity in the Neogene, when most are in siliciclastics. • The assemblage formed under high-productivity conditions. • If Late Pliocene, conditions were cool water upwelling, unusual for a limestone. • If Early Pliocene, they were non-uniformitarian warm water upwelling in a warm ocean. [ABSTRACT FROM AUTHOR]