Earthquakes. Section through the centre of earth showing the wave paths (firm lines with arrows), and arrival times (in minutes reckoned from zero time of the shock). Since there is a shadow zone free from P and S waves for wach such earthquake, it is inferred that the earth has a core which refracts the deeper waves as shown in the diagram. Holmes, 1953, p. 374.

Section through soil polygons on top of till filled by sand (partly white). Trans Canada pipeline trench.

Section through soil polygons on top of till filled by sand (partly white). Trans Canada pipeline trench. (Earl Christiansen)

Section through rimmed kettle showing superglacial till over basal till with sharp contact at right. Near Ardrossan, Alberta.

Section through ejected lava block to show different texture in centre than on rapidly cooled outside. Near Myvatn. August 4, 1960.

Section showing Whitemud Formation at base overlain by both sand and clay facies of Frenchman Formation in which channelling can be seen. Above the greenish and yellowish sands of the Frenchman lies the basal Ferris coal seam of the Ravenscrag (Paleocene) Formation. Ravenscrag Butte, Saskatchewan. May 1964.

Section showing structure of the Grand Canyon. Section from El Tovar northward to Kaibab Plateau. King 1959, p. 103.

Diagram of section of Belly River (Upper Cretaceous) along South Saskatchewan River. After Hind, 1860. Copied from a book. Pioneer Geologists in Saskatchewan.

Section from centre of a continent to its margin showing ideal arrangement of lowlands and mountain belts. King 1959, p. 5.

Section at Roche Percee measured by J. Hector, 1858. Copied from a book. Pioneer Geologists in Saskatchewan.

Roche Moutonee. Section arcoss a typical roche moutonee, showing the effect of ice abrasion where the rock is sparsley jointed, and of plucking where jointing is well developed. Holmes, 1953, p. 217.

Section across Sverdrup Basin (Raasch et al., 1961, v. 1, p. 350)

Section 63 B 73 showing base up to the grey gypsum at top of photograph. Taken from the south side of canyon toward 63 B 73 which is on the north side of the canyon.

Second solution to problem in slide 131.