240 



Carhoniferous Stratum at Baypoor. 



[AruiL 



the saline moisture to wliicli it is continually exposed, and imbedding 

 carbonized branches, leaves and trunks of trees. This bed varies from 

 a few inches to five feet in thickness, dipping 4** towards the north-east, 

 and can be traced about half a mile in an easterly direction up the 

 northern bank of the river. It is intersected by deep, nearly vertical 

 fissures, Avhich are crossed in various directions by others more super- 

 ficial. Its structure is obscurely laminar, and the more earthy portions 

 of it glitter with minute micaceous particles. Other portions seem to 

 consist wholly of carbonized woody matter, and have a tough elastic 

 feel under the hammer. Its colour varies from a greenish black to a 

 jet black. In two situations it imbedded numerous small shells, some 

 of which had been reduced to fragments, and differing from the shells 

 at present found in the river. The identification of these shells would 

 probably afford an insight into the age of the laterite hitherto a deside- 

 ratum in Indian geology. Should we feel disposed to refer the age 

 of this carbonaceous deposit to that of the coal measures of Europe, 

 the laterite here might be classed with the new red sandstone. The 

 black shale and clay is highly impregnated with sulphate of alumina, 

 and is somewhat analogous to the aluminiferous shale of the coal mea- 

 sures; and, like it, as before remarked, contains micaceous spangles 

 disseminated. The surface and sides of the fissures are frequently 

 coated with a yellowish efflorescence consisting chiefly of sulphur, iron 

 and alumina : the two former of which appear to be in process of 

 combination into the pyrites, usually seen in coal, rather than the result 

 of decomposition from pyrites. The whole has a distinctly sulphure- 

 ous odour. The carbonized branches, leaves and trunks of trees lay 

 a horizontal position in the black shale: from which, in consequence of 

 their weathering less, they often projected where w-ashed by the tide. 

 The external longitudinal fibres and annular concentric delineations of 

 some exogenous trunks were perfectly distinct. Some fragments were 

 brown, heavy, tough, and woody; others brittle, with a brilliant frac- 

 ture resembling a jet, light and bituminous; on some the thin bark 

 was perfectly distinct, and exhibited in a beautiful manner the differ- 

 ent stages of the carbonization of wood. Many fragments were pene- 

 trated with water, holding iron in solution, which had left on the sur- 

 face a glittering reddish brown enduit. 



The whole appearance of these strata, their situation and the hori- 

 zontal position of the trees, leaves, and plants embedded in them, fully 

 bear out the theory of the formation of our coal-fields and wealdens (viz. 

 that ihey are the successive deposits of drifted trees, plants, clay and 

 sand on the bed of a river or estuary) against the objections of a late 



