TRANSACTIONS OP THE SECTIONS. 77 



sandstones, limestones, coal, and the strata usually existing in all coal 

 fields. They underlie the millstone grit rocks which crop out at Ale- 

 mouth, and they overlie thick beds of a red conglomerate, accompanied 

 by slaty red sandstones, which rest on the Lammermuir Hills towards 

 the north, and on the Cheviot towards the west. There are altogether 

 fourteen beds of workable coal, the thickest of which contain about six 

 feet of pure coal. There are seven beds of marine limestone, each on 

 an average fifteen feet thick. This coal field is intersected by four 

 greenstone dykes, all of which run in a direction E. and W., and all of 

 which become thinner towards the west ; two of them run severally 

 about eight miles. The Kyloe hills consist of greenstone, which is 

 stratified, and forms part of the whin sill that runs through Northum- 

 berland. The strata are in the form of a basin, having been elevated 

 on two sides by the porphyry of Lamberton and Cheviot hills. But the 

 phenomena of the district afford clear evidence that there have been 

 two periods when tlie porphyry was ejected, one of these periods being 

 before the deposition of the stratified rocks, and the other after the de- 

 position. This evidence is aff"orded hy the conglomerate under the coal- 

 measures, Avhich in many places contains fragments of the Lamberton 

 and Cheviot porphyries, — and by the verticality of these coal-measures 

 in other places where they are in contact with the porphyry. The 

 slips or dislocations caused by these convulsions were pointed out and 

 described, with reference to a map and sections. The direction of these 

 slips was stated to be generally coincident with the dip and rise of the 

 strata, so that where the strata dip the same way continuously over a 

 great extent of country, they are all parallel ; and where they are in the 

 form of a basin, they converge to the trough of it. 



It was mentioned, that organic remains of various kinds were found 

 in the strata of the district. Remains of fish, and of the same species 

 that occur in the Lothian coal fields, viz. the Megalichthys and the 

 Gyracanthus, occur in an impure limestone that forms the roof of the 

 lowest workable coal, which limestone contains also terrestrial plants 

 and bivalve shells, resembling the Sanguinolaria. Lower down in the 

 series, and near what was probably the shore of the sea in which these 

 strata were deposited, the shales and sandstones exhibit broken frag- 

 ments of Coniferse and other plants having Serpula and Modiolce at- 

 tached to them. The workable beds of limestone are filled with all the 

 marine shells usually characteristic of the carboniferous limestones. 



The superficial deposits consist of bowlder clay which immediatelj' 

 covers the rocks, and is filled with blocks of grauwacke, basalt, and 

 granite, clearly showing that it has come from the westward. This 

 boAvlder clay is covered by sand, which in some places is sixty feet deep 

 and is continuous for many miles. Over this lies fine brick clay ; and 

 above the sand is a covering of gravel. It would appear from this, 

 that a sea had probably existed in the district, at the bottom of which 

 tlie bowlder clay, by some violent cause, had been spread, that a long 

 period of tranquillity thereafter prevailed, when at length the sea re- 

 tired, whereby gravel was spread over its bottom, and the existing 

 valleys (which are all east and west in direction) were scooped out. 



