Deep-sea benthonic foraminifera from the Crozet, Madagascar, and Mascarene Basins of the southwest Indian Ocean were studied (9-45°S, 45-80°E) to determine faunal-water mass relations. Principal component analysis of the faunal data reveals distinct trends related to depth and bottom-water potential temperature. Principal component 1 represents an average of all the faunal data. Negative values of principal component 2 reflect the importance of Epistominella umbonifera and are found generally south of 35°S latitude in the Crozet Basin and on the flanks of the Madagascar, Southwest Indian, and Southeast Indian Ridges. These negative values are associated with bottom-water potential temperatures ranging from -0.1 to 1.2°C with the high relative values (& t;= -0.4) associated with potential temperatures <= 0.8°C. Positive values of principal component 2 reflect the importance of Planulina wuellerstorfi, rare species (<= 3%), Globocassidulina subglobosa, and Astrononion echolsi, and are found on the Central Indian and Madagascar Ridges where bottom-water potential temperatures are 0.4 to 1.2°C. High relative values of principal component 2 (>= 0.4) are found with potential temperatures of 1.2°C. High negative values of principal component 3 reflect the importance of G. subglobosa and high positive values reflect the importance of Epistominella exigua, P. wuellerstorfi, and Pullenia bulloides.

End_of_Article - Last_Page 913------------