Geology . Fig. 404.—Chief Mountain. (Willis, U. S. Geol. Surv.) be as much as seven miles,1 while the throw is as much as 15,00Cfeet. Near the national boundary, the displacement of what appearsto be the same fault crowded the Proterozoic up over the Cretaceous2by a movement of equal magnitude (Fig. 403). The exact date of 1 McConnell, Geol. Surv. of Canada, Vol. II, Rept. D, p. 33, 1886. 2 Willis, Bull. Geol. Soc. of Am., Vol. 13, pp. 307, 331-5. 166 GEOLOGY these faults 1ms not been determined, but they occurred during thegeneral period of disturbance inaugurated at the close of the UpperCre
Geology . Fig. 404.—Chief Mountain. (Willis, U. S. Geol. Surv.) be as much as seven miles,1 while the throw is as much as 15,00Cfeet. Near the national boundary, the displacement of what appearsto be the same fault crowded the Proterozoic up over the Cretaceous2by a movement of equal magnitude (Fig. 403). The exact date of 1 McConnell, Geol. Surv. of Canada, Vol. II, Rept. D, p. 33, 1886. 2 Willis, Bull. Geol. Soc. of Am., Vol. 13, pp. 307, 331-5. 166 GEOLOGY these faults 1ms not been determined, but they occurred during thegeneral period of disturbance inaugurated at the close of the UpperCretaceous. Tin4 position of the Cretaceous near Livingston, Mont.,is shown in Fig. 405, while the effect of faulting on outcrops in theplains of Colorado is shown in Fig. Fig. 405.—Section showing position of Cretaceous beds at one point in the vicinityof Livingston, Montana. 2R — Archean; €, Cambrian (Gallatin and Flatheadformations); D, Devonian (Jefferson formation); C, Carboniferous (Quadrantand Madison formations); J, Jurassic (Ellis formation); Kd, Dakota formation;AY, Colorado series; Km, Montana series, and Kl, Laramie series; bbr, basic igne-ous rock, and apt, acidic rock. Length of section about 11 miles. (Livingston,Mont., folio, U. S. Geol. Surv.) With present data it is impossible to interpret all the deformations at thistime in a strictly inductive way, and differences of opinion remain composite interpretation may, however, be indicated. The facts that havejust been given relative to folding and overthrust seem to indicate clearly a lateralmovement of the crust, attended by a sub-crustal shear, and a folding andfaulting of the crustal zone. Using the methods of estimate previously set forth(Vol. II, p. 125), the thick
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