Many of the igneous rocks of the Terlingua district in west Texas contain analcite as an important mineral. The analcite-bearing rocks generally are assemblages of andesine or labradorite, alkali feldspar, augite or aegirite-augite, olivine, iron ores, and analcite. Biotite is present in some types but absent in others. Important types are analcite syenogabbro, analcite trachybasalt porphyry, analcite trachycdolerite, and analcite syenite. Analcite was formed in these rocks through an extended period from late magmatic to definitely post magmatic stages. Reaction between the analcitic liquid and earlier formed minerals resulted in a series of reaction products including analcite aegirite-augite, serpentine, albite, and zeolites.
Proceedings of the Iowa Academy of Science
©1939 Iowa Academy of Science, Inc.
Lonsdale, John T.
"Origin of Analcite in Igneous Rocks of the Terlingua District, Texas,"
Proceedings of the Iowa Academy of Science, 46(1), 252-252.
Available at: https://scholarworks.uni.edu/pias/vol46/iss1/64