Shut up

[page 53:] […] shutups, the most spectacular in the Lefthand Shutup southeast of hill 4787 […] Slickenlines document strike-slip, oblique-slip, and some normal fault movement and form as mullions, as in the Lefthand Shutup southeast of hill 4787, or fine grooves, as in both the Lower and Righthand Shutups. [page 94:] In contrast, Corry and others (1990, p. 13) believed that the Shutups are ancient features that "must have drained the central basin since it was formed in the late Eocene. The youthful appearance of the shutups, with canyon walls that are very steep to vertical (Fig. 9), is the result of their structural control. The canyons of the shutups […]

[…] Except in the driest seasons, a shallow flowing stream two or three feet wide meanders over gravel bars between these pools, disappearing and re-emerging as if by whim. But the calm, steep-shadowed serenity of the Shutups is deceiving: floods accompanying late-summer thunderstorms transform them into places of mortal peril, roaring gorges where giant boulders are tumbled about by the current's overwhelming force. So rugged is the interior of the Solitaro that a good day's expedition seldom covers more than fifteen miles, and then only with the aid of a sturdy four-wheel-drive vehicle.

Figure 9. Looking west through the Righthand Shutup. [Wiktionary editor's note: The photo depicts a valley with thick brush and trees filling its bottom; its left wall rises at a 45 degree angle and its right wall at a 70 degree angle; another slope fills the horizon, where the valley either curves left or another terrain feature rises outside the valley.] The narrow, steep canyons formed by the shutups, and the steep slopes of the rim escarpment, make it possible to pen cattle inside the central basin with limited fencing. At this location, the right side of the shutup is a rhyolite dike that has prominent columnar jointing near here. The shutups have drained the central basin since the late Eocene.

The shutups are training grounds for aspiring geologists, a glimpse into geological history through a succession of Cretaceous rocks from youngest to oldest as you ascend the drainages. The canyons are storehouses […]