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STRATIGRAPHICAL GEOLOGY 
Pyramid Conglomerates. Title is proposed for the basal beds 
of the Dakotan section as outcropping in the Pyramid Butte, New 
Mexico. 
Santa Ritan Series, Keyes (Proc. Iowa Acad. Sci., Vol. XXII, 
p. 266, 1916.) 
Seligman Limestones. Title is suggested for the calcareous 
strata in the lower part of the Supaian series, as exposed best 
perhaps in the Aubrey Cliffs, near Seligman. 
Shiwits Shales. Name is given to the uppermost red shale 
section of the Supaian series, as exposed in the Canyon walls, and 
especially around the Shiwits Plateau, north of Peach Springs, in 
Mojave County. 
Silver Shales, Keyes. (Trans American Inst. Mining Eng., Vol. 
XXXIX, p. 147, 1909.) 
Simon Limestones. Designation of the basal Mississippian beds 
carrying the Chouteau fauna, as exposed in the face of the 
Chiricahua Mountains and overlooking the San Simon bolson. 
Tanner Shales. Name assigned to the basal shale beds of the 
Moenkopian series, outcropping at Tanner’s Crossing of the Little 
Colorado River. 
Tolchico Shales. Name is given to the second shale member of 
Ward’s Moenkopian series, finely displayed around the mouth of 
Canyon Diablo. 
Torrejon Clays, Dali. (Eighteenth Ann. Rept., U. S. Geol. 
Surv., pt. ii, p. 347, 1898.) 
Trinity Sandstones, Hill. (Arkansas Geol. Surv., Ann. Rept. 
for 1888, Vol. II, p. 116, 1888.) 
Triixton Limestones. Title is applied to the middle Mississip- 
pian section, carrying the Burlington fauna. Fine sections are 
shown in western Arizona in the Grand Wash Cliffs, and in the 
Yampai Cliffs overlooking the Truxton Plateau. 
Ventana Sandstones. Term is proposed for the uppermost 
member of the Doloresian series, as displayed in Apache County, 
especially in the Ventana Mesa, near Chinle. 
Verdan Series. Name is applied to the Coconino sandstone 
and some associated layers, as especially well developed on the 
Verde River, south of Flagstaff. 
