lO"!' Mr. F. Forster's Ohseyxat'ions on the South Welsh Coal Basin. 



following section, taken in the centre of the Basin at Llanelly, (about 

 2j. miles to the west of diagram. No, 1.) 



DIAGRAM, No. 2 



Numbers 1, 2, 3, and 4, are the pits by which the strata have been proved. The pit 

 No. 3 is put down within 30 yards of the centre of the Basin ; the seam (d), 2 feet in 

 thickness, locally termed the " Rosy Vein," was intersected at the depth of 57 fathoms : — 

 the seam (c), 4 feet in thickness, called the " Fiery Vein," at 67 fathoms ; and the seam 

 (b), 2 feet thick, and called the " Golden Vein," at the depth of 85 fathoms. The lowest 

 seam (a), 2 feet in thickness, and known by the name of the " Bushey Vein," has been 

 proved by the other pits, and would be found here at the depth of about 103 fathoms. It 

 does not appear that any change takes place here in the direction of the dip and rise line, 

 on the opposite sides of the centre, nor does any break in the strata occur, similar to that 

 exhibited in Diagram, No. 1., although several small faults, known in our northern districts 

 hj the name of "hitches," intersect the strata near the centre. The inclination, in accordance 

 with the general law, which seems to influence the strata throughout the whole of the 

 Basin, is greater on the south than on the north side. The quality of the seams of Coal 

 delineated in the above Diagram, undergoes a gradual variation from north to south ; the 

 north crops of the seams being composed of Free-burning Coal, becoming more bituminous 

 as they approach the centre, and passing into decided Bituminous Coal on its southern side- 



The workable seams of Coal rising to the northward in this division, 

 including the Gelle Gille seam, which crops out to the west of the line 

 of section, will be six in number ; and assuming that the Trosserch 

 seams and two others, not shewn on the section, which are supposed 

 to crop out to the north of them, are together 10 feet, their total 

 thickness will amount to 25 feet. The aggregate thickness, therefore, 

 of the workable seams on the north side of the centre will be 85 feet, 

 and their number 27. 



The line of section, after crossing the centre or " saddle," proceeds 

 in the direction of the full rise of the strata (about S. 30° W.) to the 

 bank of the Llwchor river. The first south-crop seam, called the 

 " Fiery Vein," is 7 feet thick, and lies at a distance of from 40 to 50 

 fathoms above an 8 feet seam, called the " Golden Vein," which at a 

 former period, has been extensively worked to the depth of 40 fathoms, 



