CHAPTER IX. 



THE MAEKAGUNT PLATEAU. 



Description of its general features aud relations. — Dog Valley. — One of the principal cmptive centers of 

 trachytio masses. — Characters of the lavas. — Basaltic eruptions and conglomerates. — Bear Val- 

 ley. — ^Little Creek Peak aud Bear Peak. — Tufaceous beds. — Overlying lavas. — Degradation of the 

 plateau. — View from the summit of Little Creek Peak. — Journey over the Mark^gunt. — Succes- 

 sion of eruptions, audesites, trachytes, rhyolites, basalts. — Central gi-oup of ancient basaltic 

 cones. — Their dilapidated condition. — Panquitch Lake. — Exposures of contact between the lavas 

 and sedimentaries. — Modem basaltic outpours. — Other basaltic fields. — Relative recency of the 

 basalts. — Surface changes since the eruptions. — Connection of the Markslgunt basalts with those 

 of more southern regions. — Sedimentary formations of the Western and Southern Markdgnnt. — 

 Tufaceous deposits. — Pink Cliff beds. — Correlation of local Tertiaries with those of the Wasatch 

 Plateau. — The Cretaceous. — Jurassic and Triassic formations. — The Shiniirump. — The Southern 

 Cliffs of the MarkiJgunt. — Outlook to the far southward. 



The Markdgunt Plateau lies southwest of the Tushar. From the 

 southern salient of Midget's Crest a considerable portion of its exjjanse 

 may be seen, though the view is not a very good one. In truth there is 

 nowhere to be obtained a good panoramic overlook of the MarkAgunt, for 

 there is no stand-point sufficiently lofty. The observer on this summit, 

 standing more than a mile above tlie neighboring lowlands, will find it diffi- 

 cult to realize that the most distant verge visible along the southwestern 

 horizon has an altitude about equal to his own. With the exception of 

 two respectable masses shooting up in the middle-ground of the picture, 

 there are no peaks nor strongly individualized summits; nothing, in fact, 

 to suggest mountains. It is a broad expanse of rolling hills and ridges, 

 rarely exceeding 600 feet in altitude. The whole platform has a slight dip 

 to the eastward ; being, however, not an inclined plane, but dish-shaped. 

 The eastern base of the plateau lies at the foot of the southern Sevier 

 Plateau, being the thrown side of the great Sevier fault. From this line it 

 rises by a very slow ascent, not exceeding 2^°, westward to its summit. 

 The character of the gradients will be understood by a reference to the 

 stereogram. (Atlas sheet. No. 5.) The general relations of this plateau 



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