Geological Survey Bulletin Volume 982

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. Excerpt: ...Canyon, and on the east limb of the Webster syncline. Altitude, 7,275 feet. Trench F. SWViSW sec. 9, T. 10 S., R. 45 E., on the south bank of the second large gully 1 mile southwest of Wells Canyon, and on the west limb of the Webster syncline. Altitude, 7,650 feet. Trench G. SW14SW14 sec. 9, T. 10 S., R. 45 E., on the south bank of the second large gully 1 mile southwest of Wells Canyon, approximately 200 feet east of trench F, and on the west limb of the Webster syncline. Altitude. 7,570 feet. "Trench H. NWi/4NEy4 sec. 9, T. 10 S., R. 45, E., in Wells Canyon approximately 75 feet west of Trench E, and on the east limb of the Webster syncline. Altitude, 7,300 feet. Trench I. SMjSWVi sec. 34, T. 9 S., R. 45 E., on the north side of Deer Creek, and on the east limb of the Webster syncline. Altitude 7,000 feet. CONTINUITY OF MINOR PETROLOGIC UNITS Stratigraphic sections at the base of the phosphatic shale member of the Phosphoria formation are exposed in trenches C to F and I (pI. 2). Stratigraphic sections at the top of the member are exposed in trenches A. B, G, H, and I (pl. 3). Trench I (pls. 2, 3) contains the only stratigraphic section of all the beds between the underlying limestone of the Wells formation and the overlying Rex chert member. Trench I is D/2 and 2% miles north of trenches E and F, respectively, and V/2 and 1% miles east of trenches C and D, respectively (pi. 1). Although the distances involved are not long, many lithologic differences exist between trenches. Folding and faulting have caused duplication and possibly omission of beds in this area. The correlations indicating presence or absence of continuity of beds between the sections shown on plates 2 and 3 are based on lithology, texture, structures, and stratigraphic sequence. The upp...