LANDSLIDE AT CLEVELAND, OHIO 627 



was about 250 feet long, and ran in a northeast and southwest direction for 

 about 100 feet, after which it turned nearly west for the remainder of the dis- 

 tance. The fissure was about 30 to 40 feet deep, as far as could be observed, 

 and was filled up to that depth with loose joint blocks and debris which had 

 fallen from the walls. The crack followed almost entirely weathered joint 

 planes, which were stained with limonite from the decomposition of pyrite and 

 marcasite contained by these shales in variable amounts. It was in the wall 

 of the fissure on the cliff side that the large joint plane in the Chagrin men- 

 tioned previously was observed. It was evidently this surface which gave 

 direction to the fissure for the first 100 feet of its course (see plate 106). The 

 block broken off by this crack resembled an elliptical cone truncated at the top. 

 The upper surface of this conical mass was approximately 250 feet long and 30 

 feet wide. Around the base on the valley floor it measured, roughly, 300 feet 

 and was 112 feet high. Mr H. D. Pallister kindly attempted to compute its 

 dimensions, which was difficult because of lack of knowledge of its internal 

 outline. He used 3,200 pounds for the weight of a cubic yard of drift and 

 4,533 pounds for the Bedford and Cleveland, while 4,7GG pounds was used for 

 a cubic yard of Chagrin. By this method it was found that there were 18,521 

 cubic yards, weighing 43,530 tons. Since this seemed rather small, the writer 

 calculated its contents as a solid bounded by rectangles in order that an idea 

 of the maximum contents might be reached, and found that the block would 

 contain 37,330 cubic yards and weigh 87,732 tons. Since the slide has fur- 

 nished the brick company with shale for over 15 months, it is evident that the 

 larger estimate is more nearly correct. 



BUCKLINO 



The buckling, which is the most interesting feature of the landslide, was 

 first noticed on Tuesday afternoon, August 18, about. 24 hours after the first 

 appearance of the crack (see plate 107). The axis of this anticlinal fold was 

 traceable for about 200 feet in the shale at the base of the cliff, following 

 around the head of the rounded point, until it finally became lost in the frag- 

 ments which had fallen down from above as a result of the dislocation. The 

 maximum height of the anticline was about 4 to 5 feet, while the greatest 

 width attained was 8 to 10 feet. The buckle reached its greatest height about 

 a week after the development of the fissure, but has continued steadily for 

 over a year, although the rate of elevation has constantly decreased. The ex- 

 tent of the motion may be gathered from the amount of work which has been 

 required for the excavation of the brick company's sewer, which was crushed 

 by the buckling. This sewer runs along near the foot of the displaced block 

 about 7 feet below the valley floor. It required 34 days for 2 teams and 7 men 

 to excavate the debris in the sewer trench, which has since been entirely filled 

 again by the buckling movement. Since the axis of the anticline lies between 

 the grinding pans and the shale bank, the ground is kept shoveled off as fast 

 as it arches up, and the buckle was not allowed to attain any size except 

 toward the southwest end of the slide. 



The officials of the brick company maintain that the buckling started first, 

 and that no settling was perceptible until about 2 days after the formation of 



