Contracting earth. Formation of arcuate fracture due to contraction. Jacobs et al., 1959, p. 355.

Contour map of Scripps and La Jolla submarine canyons. Shepard, 1960, p. 136.

The hypothesis of continental drift has been invoked by some geologists to explain the occurrence of Permo-Carbiniferous tillites in Africa, South America, Australia and India. Arrows show the direction of ice movement inferred from striations (Zumberge 1958, p. 277).

Contact between Upper Cretaceous Judith River (our Belly River) and the overlying Bearpaw shales. Near bridge crossing Missouri River along Malta-Lewistown highway, Montana, May, 1964.

Contact between second interglacial (Leinan) laminated silt and uppermost till. See Wickenden, 1931b, section C. Near Stewart Valley, Sask. See also Christiansen (1959).

Shows a close-up of a pipe being connected on oil rig, Rapdan oil field, Saskatchewan.

Conglomerate in Newark Series, N.Y. State Thruway, about 1 mile west of Spring Valley, Rockland County, N.Y.

Confined and unconfined aquifers. Artesian wells may be flowing or non-flowing depending on whether the pressure surface is above or below the ground surface. (A) Wells in an unconfined aquifer. (B) Artesian wells in a confined artesian aquifer. Zumberge, 1958, p. 135.

Conceptual scheme for the evolution of landscape in a humid temperature climate. The transition from, late youth ti early maturity is marked by the disappearance of remnants of the initial surface and by smoothing (grading) of valley side-slopes. In early maturity, most of the landscape is occupied by valley side-slope; in late maturity, by the valley flats of streams. The dashed line on each block represents sea level.

Conceptual diagram of ice-thrusting.

Concentration of 'pseudomelania hendricksoni' on limestone interbedded with platy sandstone of Cretaceous Mosby formation. Morrison Dome, Little Rocky Mountains, Montana.

Concentration of 'Gryphae sp.' on exposed bedding plane of Rierdon formation. South side of Zortman Butte, Little Rocky Mountains, Montana.

Concentration of boulders on side of glacial drainage channel. These boulders removed from road. South of highway 5; 30 miles east of Saskatoon, Sask.

Comparison of the Monterey Submarine Canyon to the Grand Canyon of the Colorado River. Profiles drawn at the same scale and based on the same number of observations. Shepard, 1960, p. 140.

Comparative profiles of the continental slope, illustrating the various types. Shepard, 1960, p. 112.