EECBNT FAULTS. 281 



which a person can descend a number of feet lower than the surface of the 

 desert. 



The fault described in the last paragraph is at such a distance from 

 the highlands to the westward that no alluviation has taken place in its 

 neighborhood. There has, therefore, been no transfer of load from one 

 side of the displacement to the other. The thrown side of the fault under- 

 lies the broad desert and was lightened previous to the last fault-movement 

 by the removal of 500 feet of water from its entire surface. It is quite 

 evident, therefore, from the nature of the facts, that the unequal loading of 

 contiguous orographic blocks, wliich has been assumed as an explanation 

 of fault movements in certain instances, cannot be considered an element 

 in the present example. 



A fault along the northern side of Honey Lake Valley shows about as 

 great an amount of post-Lahontan movement as any in the basin. In this 

 instance tlie trend of the fault is irregular, but in general its course is north- 

 west and southeast; its hade is nearly perpendicular, and the recent displace- 

 ment at times exceeds a hundred feet. The thrown block underlies Honey 

 Lake Valley. From the position of the present lake and the direction of 

 drainage in the valley, it seems evident that the mountains between Smoke 

 Creek Desert and Honey Lake Valley must have been upheaved to pro- 

 duce this fault. A similar but more gentle movement of the same mount- 

 ain mass would account foi- the recent scarp described above which crosses 

 the Smoke Creek Desert. 



The faults represented on Plate XLIV, to the north of the Lahontan 

 drainage area, are of the same character as those already described, and 

 will require but a word of explanation at this time. 



The recent displacement on the west side of Surprise Valley, California, 

 has a throw varying from 20 to 50 feet, and may be traced for nearly a 

 Imndred miles across alluvial slopes and gravel embankments of Quaternary 

 age. As in numerous other instances, its course is marked by thermal 

 springs, some of which are of high temperature and afford a large volume 

 of water. The fault along the eastern base of the Stein Mountains, Oregon, 

 falls in this same category, and together with other similar displacements 



