clxii Report of the Mineralogical Survey [No. 126*. 



348. The existence of coal all over the world, and always in the 

 same geological situation, is another proof that even in * * 



***** condition or state of 



things, which must have been common to every country of the globe. 

 Pursuing the analogy taught by the facts learned in the coal fields of 

 England, that valuable mineral has been brought to light in almost 

 every part of the world, it may not therefore be uninteresting to enter into 

 some little explanation on this subject, in order to judge whether the 

 deposit may be expected in this quarter, as in any way connected 

 with the series of facts described. 



349. The coal formation though, as has been observed, owing its 

 origin most probably in every country to the action of some general 

 cause, may yet be considered, as far as appearances are concerned, to 

 be a local deposit, inasmuch as it is always of limited extent compared 

 with the other strata. Its place in the system is well marked, nor 

 has any bed of coal worth mention ever been found out of that place. 

 It is known to overlie a limestone, which from its relation to the 

 coal, has been called carboniferous, and which itself lies upon the rock 

 called the old red sandstone, the lowest of the secondary strata. Above 

 the coal measures is found the newer red or saliferous sandstone. 

 Between these two members of the series, it has always been observed 

 to hold its place ; subordinate strata occasionally intervening, occasion- 

 ally being wanting, but the coal never occurring, that is, in any quan- 

 tity above the latter, or below the former rock. 



350. This would seem to be a sufficiently definite arrangement to 

 enable us always to pronounce on the greater or less probability of 

 finding this useful mineral in any tract in which the succession of 

 rocks has been accurately traced. Applying the principle to the present 

 survey, it will be found that limiting facts are wanting, although the 

 general presumption is strongly in favor of the existence of a coal 

 formation. Thus we have the saliferous or newer red sandstone on 

 the border of the mountain tract, dipping N. E., giving the promise 

 of older or inferior deposits to the Southward ; and again at Dehli, we 

 have the old red sandstone, leaving it a natural inference, that in the 

 intermediate space, intervening formations will be found. 



35 1 . The great coal field of Northumberland and Durham is situated 

 in millstone grit and limestone shale (the upper anomalous beds of the 



