268 ANNALS NEW YORE ACADEMY OF SCIENCES 



ings, being reserved for underground working by means of a shaft out- 

 side. It is exposed in the southerly wall. 



The top of the coal is reached on the eighth bench, where one finds ,\ 

 few feet of the overlying shale ; but there is no continuous section above, 

 as at Domergue, for this easterly wall is cut by some important faults, 

 whereby the coal reaches successively higher benches toward the south, 

 before the folded area has been reached. In descending the incline from 

 the thirteenth to the twelfth bench, one crosses a fault which brings the 

 conglomerate sandstone^ No. 1 of Domergue, against the laminated beds 

 No. 11 of Domergue, while on the eleventh bench that sandstone and 

 the coal are almost in contact. This fault appears on the thirteentli 

 bench at the point of the hill, but it is equally well defined at the north- 

 erly end, where exposures reach to the fifteenth bench and the coal, 

 rising eastward, is shown much folded and with only 10 feet of shale 

 between it and the fault. This fault, viewed from the southwest corner, 

 is very distinct from the thirteenth bench down into the coal of the 

 ninth. The measurement of the coal already given was made on the 

 easterly side of this fault; at a few yards southeast, the coal reaches to 

 the tenth bench. The other faults are of slight vertical extent. 



The interval between the coal and the great sandstone is not fully 

 shown in this wall, owing to the faults, but the beds in contact with the 

 coal resemble those seen in the Fraysse and Domergue workings. The 

 sandstones above are light gray, with many layers of pea to chestnut con- 

 glomerate and are not far from 200 feet thick ; while near the top of the 

 hill are reddish or reddish brown beds which have been recognized as 

 Permian. When the great disturbance occurred, the massive rocks above 

 broke into huge blocks or were pushed into a broad fold, but the coal and 

 shale, the weaker materials, were crumpled, thrown into multitudinous 

 petty folds and broken by local faults. At the Bourran shaft, one is 

 apparently outside of the faulted area, for there one sees the shales and 

 sandstones to fully 200 feet above the coal, the dip of rather more than 

 30 degrees being ignored in the measurement. The succession seems to 

 be regular on the westerly side of the Decazeville decouverte, where the 

 section resembles that at Domergue, except that two sandstone beds, six 

 to eight feet thick, in the lower part contain streaks of conglomerate with 

 pebbles sometimes one inch in diameter. Several sandy layers show 

 many impressions of plants and of stems, some of them large enough to 

 be regarded as tree trunks. 



Standing at the northwest corner of this decouverte and looking 

 toward the southeast, one sees in the southerly wall a sharp carinated 

 fold, whose abrupt middle portion is marked by the light-colored shale 



