IN THE INDO GANGETIC MOUNTAINS. 401 



the sand-stone beds. They also contain thin seams or veins of the bole, 

 which forms the finer part of the general basis. These beds, if seen un- 

 connected with the other strata, would be described as a deposit of brick earth. 

 They occasionally pass into a well defined reddish shale, having a perfect 

 schistose structure, and in hard specimens frequently not distinguishable 

 from some varieties of the older slates. 3. Conglomerate Beds, which 

 consist of the preceding reddish earth as a basis, with perfectly rounded frag- 

 ments of Quartz Rock, Grey Wacke, Granite, Horn-blende Rock and Lime- 

 stone. The first constitutes nine-tenths of the number, the last is the most 

 rare of all. The arrangement of these water- worn fragments though not 

 agreeable to the position which gravity would assign them, as far at least as 

 size is concerned, is yet very regular, both as regards the definiteness of each 

 stratum, and the parallel position to the stratiform, which those fragments 

 hold that have any thing of a flat shape: some of these layers alternating with 

 argillaceous beds, or occasionally with sand-stone strata, are not above three 

 inches thick, while others are fifty feet. It is not unusual to see them gra- 

 dually extenuated till they disappear, thus forming what are called Lens- 

 shaped strata. Sand-stone occasionally, but rarely, forms the basis.* 



It is then in this rock that the Coal occurs, in every instance but 

 one, in the sand-stone type. Its mode of occurrence, as far as I have been able 

 to judge, is in flat veins or seams, more or less incHned to the horizon. The 

 quantity is never considerable, the largest vein yet discovered, being about 

 nine inches or a foot in thickness. In general they are much smaller, and 

 some are not more than one-twentieth of an inch. The line of contact with 

 the sand-stone is always sharp, and well defined, there being nothing inter, 

 posed analogous to the shale of the Coal formation, and the only peculiarity 



* In strictness perhaps, there are but two types, the Argillaceous and the Arenaceous— the 

 Conglomerate being considered a modification of either. 



