Geological Sketch of the Coal District of Saint- 

 Etienne, department of the Loire.* By M. 

 Beaunier, Engineer in Chief of the Royal 

 Mining Corps. 



[Annales des Mines, 1816.] 



THE coal district of the arrondissement of St. Etienne 

 is contained in every direction within a basin of primitiTe 

 rocks, extending from SW. to NE. between the Loire and 

 the Rhone, towards the points, where those two rivers, 

 flowing in contrary directions, are nearest to each other. See 

 Plate I. 



This basin swells out considerably ; towards the Loire on 

 the west, its greatest breadth, taken in the meridian of 

 Roche-la-Moliere, is 13,000 metres [42,652 feet] ; its edges 

 approach each other towards Saint-Chamond, and follow 

 thence both sides of the river Gier, parallel with its course 

 to the Rhone, eastwards to the limits of the department of 

 the Loire : the basin is continued without sensibly altering 

 its direction to and even a little beyond + the Rhone. 



At Rive de Gier the coal formation is not more than 2,300 

 metres [7,546 feet] in breadth, and at Tartaras it is still 

 less. Its greatest length, measured from St. Paul d« Cor- 

 nillon (on the Loire) to Givors (on the Rhone), is 46,250 

 metres [151,742 feet]. It covers a surface of 221.43 square 

 kilometres [about 87 square miles]. When speaking of the 

 limits of the coal basin, a continuous line is understood, 

 which would mark the separation on the surface of the coal 



* This Sketch forms part of a detailed account of the manner of work- 

 ing tile coal mines &c. in the above district. (Trans.) 



t Traces of coal are found at Ternay, on the left bank of the Rhone. 



A 



