CHAPTER IX. 

 THE MAEKAGUNT PLATEAU. 



Description of its general features and relations. — Dog Valley. — One of the principal eruptive centers of 

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

 ley. — Little Creek Peak and Bear Peak. — Tufaceous beds. — Overlying lavas. — Degradation of tho 

 plateau. — View from the summit of Little Creek Peak. — Journey over the Markagunt. — Succes- 

 sion of eruptions, andesites, trachytes, rhyolites, basalts.— Central group of ancient basaltic 

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

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

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

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

 Tufaceous deposits. — Piuk Cliff beds. — Correlation of local Tertiaries with those of tho Wasatch 

 Plateau. — The Cretaceous. — Jurassic and Triassic formations. — Tho Shinarump. — Tho Southern 

 Cliffs of tho Markagunt. — Outlook to tho far southward. 



The Markagunt Plateau lies southwest of the Tushar. From the 

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

 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 the 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 GOO 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 2J°, 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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