ZEOLITE FACIES ALTERATION OF SANDSTONES IN THE SOUTHLAND SYNCLINE, NEW ZEALAND.

Abstract

Studies in a 10. 4 km sequence of Mesozoic sediments in the Southland Syncline adjacent to the Taringatura district indicate that individual mineral ranges overlap even more than previously described. Laumontite, heulandite, and albite occur throughout the section, and prehnite extends from the base to within 1. 5 km of the present top; analcime does not occur more than 7 km below the present top. The zeolite facies is best regarded as a mineral facies bridging the transition from diagenesis to metamorphism and including mineral assemblages produced by processes that may be regarded as diagenetic, metamorphic, and hydrothermal. The complexity of mineral distribution patterns is attributed to the interplay of many factors, including the effects of parent materials.