GEOLOGIC CORRELATION 
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Truchas Slates. The upper slate section of the Archeozoic succession 
at Picuris, north of Santa Fe. 
Trav ester Shales. Variegated beds lying immediately above the Exter 
sandstones well displayed in Travester canyon in northeastern New 
Mexico. 
Trujillo ShaleSf Grould. (Water Supply and Irrig. Pap., U. S. Geol. 
Surv., No. 191, p. 26, 1907.) 
Yalencian Ser^ies. Latest pre-Cambric succession of volcanics and 
granites. 
Vermejo Knowlton. (Am. Jour. Sci., (4), Vol. XXXV, p. 
527, 1913. Probably exact equivalent of Mesa Verde shales. 
Washita Limestones^ Shumard. (Trans. St. Louis Acad. Sci., Vol. I, 
p. 583, 1857.) 
Wingate Sandstones, Dutton. (Sixth Ann. Kept. U. S. Geol.. Surv., 
p. 136, 1885.) 
Yeso Shales, Lee. (Bull. U. S. Geol. Surv., No. 389, p. 9, 1909.) 
Term restricted to middle section of Bernalillan series. 
Ysidro Shales. The thick argillaceous member of Proterozoic sedi- 
ments lying above the great quartzite, which is best exposed in the 
sharp, truncated arch in Tijeras canyon between the Sandia and 
Manzano ranges. 
Zunian Series, Dutton. (Sixth Ann. Kept. U. S. Geol. Surv., p. 137, 
1885.) 
