Notices of Memoirs — The Jherria Coal-field, India. 19 



The Damuda series, which, has three sub-divisions, is characterised 

 by its containing coal. The bottom beds consist of felspathic grits, 

 sandstone with seams of coal, carbonaceous shales, conglomerates, 

 etc. ; then come carbonaceous shales with ironstones, forming the 

 middle sub-division ; and at the top, thick-bedded, and yellow 

 slightly calcareous sandstones. With the exception of the middle 

 sub-division, coal occurs at all depths in the Damuda series. 



The Boulder-bed of the Talchir series, which is, more properly 

 speaking, a coarse conglomerate, consists mainly of masses of gneiss 

 and quartz, of about one foot in length and three to six inches in 

 breadth, imbedded in a matrix varying in texture from a coarse- 

 grained sandstone to the finest silt. One is apt, at a first glance, to 

 attribute to the agency of ice a share in the transportation of the 

 larger blocks. But the author states that on examining the evidence 

 he can find none to justify such an hypothesis. No scratchings or 

 groovings occurred on any of the stones, nor have they been derived 

 from any very distant source. The larger blocks sometimes retain 

 the primitive form in which they were broken off from the parent 

 mass. A recent visit to the Straits Settlements led the author to 

 conclude that the beach deposit which is forming there at the pre- 

 sent time is analogous to the so-called Boulder-bed. 



No coal has as yet been discovered in the Talchirs. In the Damuda 

 series the coal-seams appear to be very irregular, and to vary much 

 in thickness. In the upper sub-division there is a general tendency 

 to ignition in all the coal seams, owing, most probably, to the pre- 

 sence in them of iron pyrites, which gives rise to spontaneous com- 

 bustion. Metamorphism is produced in the shales either above or 

 below, and it is of a varied character. Sometimes the beds become 

 like well-burnt bricks, or obtain a rough vesicular appearance. 



A caking variety of coal is procured at one locality, which more- 

 over gives out a copious supply of gas, burning with a rich yellowish 

 white carburetted flame. 



Many seams are much injured by the trap-dykes wlaich ramify 

 through them and render the coal useless. In one instance the coal 

 assumes every variety of form and texture, passing from a light 

 vesicular pumice-like stone through all the intermediate stages 

 until it becomes a hard dense columnar mass. 



The seams vary in thickness from a few inches to twenty feet, 

 and more. 



The quality of the ironstones is very poor, and they are so 

 siliceous that even the native Kummars can do nothing with them. 



In a note, appended to the report of Mr. Hughes, Dr. Oldham 

 says, that if, in calculating the probable quantity of coal obtainable 

 from this field, we take twenty feet as a fair average thickness 

 of workable coal — the mean of all the sections drawn by Mr 

 Hughes — and make allowances for the impersistence of the beds 

 by supposing that they will extend over less than a third of the 

 area of the field, — say sixty square miles, we should have an avail- 

 able supply of coal amoimting to about 465 millions of cubic yards, 

 or, rough y, tons. 



