496 / HARLEN BRETZ 



Canby, Ore. (4 mi. east of). Several erratic bowlders; granite or gran- 

 odiorite, porphyritic rhyolite, and quartzite. Altitude 323 ft. A.T. Have 

 been blasted out of the soil in clearing a field. Local authority states that a 

 granite bowlder like those in this group lies on the plateau tract 4 to 5 mi. 

 north of Canby. Its altitude must be about 450 ft. A.T. 



Dilley, Amity, and Corvallis, Ore. Diller found foreign bowlders near 

 these places in the Willamette Valley, the highest at 250 ft. A.T. He quotes 

 local authority for their occurrence as high as 1,500 ft. A.T. "near" Oswego, 

 Ore., but there are no elevations of more than 950 ft. A.T. near enough to 

 this place to be referred to its locality. 



Granite bowlders are very rare in the Gorge, east of the Willam- 

 ette broadening. Only one has ever been seen by the writer and 

 none are noted in the literature. The lone bowlder lies in Hood 

 River Valley, Oregon, on the summit of Van Horn Butte, a small 

 cinder cone three-quarters of a mile southeast of Van Horn. It is 

 of granite. Its altitude is between 800 and 900 feet A.T. Imme- 

 diately east of the Gorge, however, the foreign bowlders are more 

 common than in the Willamette Valley. They occur on the 

 eastern flank of the easternmost anticline of the Cascade Range, 

 about the city of The Dalles, Oregon. 



The Dalles, Ore. Granite bowlder on summit of terrace immediately 

 south of the city reservoir. 



The Dalles. Valley of Mill Creek, i| mi. from town. Large granite 

 bowlder lies in the valley ; probably has fallen from the summit of the bluffs, 

 about 500 ft. A.T. 



The Dalles (about 6 mi. west of), on old Hood River road. A dozen or 

 more angular fragments of granite, 2-3 ft. in maximum diameter, grouped 

 as though the result of frost action or blasting of an original large bowlder. 

 Altitude about 1,200 ft. A.T. 



The Dalles (about 6 mi. west of), north of old Hood River road. Granite 

 bowlder, maximum diameter about 3 ft. 500 ft. A.T. 



Arlington, Ore. (i mi. east of). 30 to 40 angular pieces of granite, from 

 2 to 6 ft. in maximum diameter, grouped within a radius of 25 ft. Altitude 

 800 ft.+ A.T. Estimated volume of exposed granite material, 500 cu. ft., 

 equivalent to an original bowlder about 7X7X8. The granite is light gray in 

 color, composed of quartz, feldspar, mica, and hornblende, and contains 

 lenses and fragments of a dark ferromagnesian phanerite. Portions are a 

 true intrusion breccia. Many of these huge granite bowlders are said to lie 

 on the slopes south of Arhngton. Many of them have been broken up for use 

 in cemetery monuments. 



Roosevelt, Wash. Slates, diorites, quartzites, and several varieties of 

 granite are all represented in cobbly and bowldery fragments up to 1,000 ft. 



