Vol. 52.] 



LUSTRES ' OF MONT JOVET (SAVOY). 



boniferous ; the cliffs above by Triassic dolomites and gypsums ; 

 the highest meadows and the central peaks by the rocks whose 

 age is in dispute. 



The area more especially examined was the north-western 

 quadrant of the mountain, which is included in the sketch-map, fig. 1. 



Fig. 1. — Sketch-map of the north-western quadrant of Mont Jovet. 



Scale 



80.OU0 



792 inch to the mile. 



The Carboniferous rocks are of the ordinary type of this series in 

 the Tarentaise ; good sections and exposures can be seen on the 

 banks of the Isere, and around the hamlets of Hauteville and Notre 

 Dame du Pre, at the height of 2500 feet above the floor of the 

 valley. The superposition of the Triassic rocks to these can be 

 clearly seen around the latter village, for the Carboniferous beds 

 there form a platform upon which the Triassic limestones rest. 



It is unnecessary to give any description of the characters of the 

 Carboniferous and Triassic rocks, but those of the third series 

 require more careful notice. For the question as to whether or no 

 these are part of the ' schistes lustres ' can be determined by litho- 

 logical evidence alone. 



The rocks in question consist of three main types : 1st. A series 



