36 C. H. Hershey — Cretaceous Outliers in California. 



in Bully Ciioop peak. On the south side of this range the 

 Cretaceous strata dip away at an angle about the same as the 

 general slope of the mountain, and Cretaceous remnants occur 

 at a considerable height on its flank. Indeed, Cretaceous peb- 

 bles and the gold derived from the basal conglomerate are 

 widely scattered over the slope and indicate that Cretaceous 

 strata in place have but lately disappeared from it. Near 

 Harrison Gulch and at Good's Pass, where the ridge is lowest, 

 the Cretaceous strata reach to the very summit and curve over 

 its top. A careful reconstruction of the plane of the base of 

 the Cretaceous upon data furnished by the basins on the north 

 of the ridge and the Cretaceous border on its southern slope 

 shows that the summit and slopes of this range must corre- 

 spond roughly with the Cretaceous base-level upon which, 

 after submergence, the Horsetown was deposited. It is the 

 Cretaceous base-level brought to light by erosion. This base- 

 level was deformed near the close of the Cretaceous to just 

 about the same extent as is the present surface. The north- 

 east-southwest range of which Bully Choop is the principal 

 peak is, in a certain sense, a structural range although its 

 present topographic prominence is due entirely to erosion. It 

 almost exactly coincides in position and form with a post-Chico 

 range. The most remarkable thing about it is that this post- 

 Chico mountain range was thrown up almost at right angles to 

 the strike of the metamorphic formations forming its core and, 

 hence, to the post-Jurassic mountain system. If the post- 

 Chico Bully Choop range rose rapidly enough so that its sum- 

 mit was not materially reduced by erosion during the move- 

 ment, at its completion it was a ridge with a base on the 

 average 12 miles wide and rising in its highest peak over 7,000 

 feet above the lowlands on the south and iSOO feet above the 

 deepest basin on the north. It became the main drainage 

 divide and has continued so to the present. 



We do not know whether the same sharp deformation of the 

 surface in post-Chico time persisted over the entire Klamath 

 region, but there are evidences that it did. Wherever the 

 Cretaceous strata are found on the borders of the Klamath 

 region, they are tilted at a considerable angle. On the north- 

 eastern flank of the mountains, in Shasta Yalley, in the Sis- 

 kiyou Mountains and in the Rogue River Yalley in Oregon, 

 the Cretaceous strata rest upon the metamorphic formations 

 with their original contact, but are tilted toward the northeast 

 at a high angle, in a few places nearly vertical. There is a 

 general rise of the Klamath region toward the northeast and 

 the highest portion of the upland occurs on the immediate 

 border, just beyond which the surface abruptly falls away to 



