STEVENSON, COAL BASIN OF COMMENTRY 
163 
continuous deposit, but that they were always distinct. His conclusions 
were confirmed by Fayol’s studies in Commentry and Montvicq. 
In going southward from Paris by way of Orleans to Monthupon, one 
rises by a succession of broad benches until, at the latter city, he is on an 
extended alluvial plain, 214 meters above tide. There the valley of the 
Cher is bounded at the east by a bold wall with almost level crest, clearly 
the edge of a higher bench. The railroad to Commentry, quickly leaves the 
Cher valley, enters a close gorge in granitic rocks, up which it climbs with 
difficult grade to the station of Chamblet-Neris, 307 meters above tide. 
Just before that station is reached, the rock changes from granitic to sedi¬ 
mentary, the gorge opens into cultivated territory and one sees, on both 
sides, flat-topped hills marking a higher bench. This is reached at Com¬ 
mentry, where the station is 375 meters above tide, or 525 feet above Mont- 
lu^on. The highest plain within the eastern part of the basin is about 400 
meters above tide or approximately 600 feet above Montlu^on. Points on 
the border of the basin attain, according to Fayol, 450 meters, but they are 
projections of granite. Within the basin, on the northern and eastern sides, 
one finds these three well-marked base-levels at 400, 375 and 307 meters 
above tide, while covering the whole surface is a deposit of recent gravels 
seldom more than 15 feet thick. 
The Commentry Basin. 
The basin of Commentry, according to Fayol, 1 is about nine kilometers 
long, averages about three kilometers wide and is about 700 meters deep — 
the longer axis being rudely east and west. De Launay’s map, already 
referred to, shows that the northern border is a narrow strip of mostly mica 
schist, behind which is granite to the little basin of Montvicq, six kilometers 
distant. This strip of schist bends around the eastern end, but there one 
finds behind it, not granite, but a broad band of gneiss, which extends 
westwardly along the southern border for about three kilometers. But 
along the rest of the southern border as well as at the west, the sedimentary 
rocks are cut off abruptly by the granite, which extends almost to the allu¬ 
vial plain of the Cher. The region southward from the basin of Commentry 
rises rapidly and appears to be mountainous, but toward the north, as 
already stated, the surface falls off in a series of steps toward the sea. 
Fayol states that at the northwest corner of the basin there is a small 
area of Permian rocks, but elsewhere only those of the Coal Measures are 
found, with a thin layer of alluvial material covering the surface. He 
Commentry, p. 21. 
