Mr. Buddle's Synopsis of the Ne*wcastle Coal Fiald. 225 



No. XXIII. — Reference to the Sections of the Strata of the Newcastle 

 Coal Field — By John Bubble, Esq. 



Read January 17, 1831. 



The horizontal scale of these Sections is 400 yards to an inch, or 4t1j 

 inches to a mile. The vertical scale is 200 yards or 100 fathoms to an 

 inch, consequently the apparent angle of declination is double the 

 natural fall of the strata. 



The Sand Stone, or Post strata, are coloured yellow ; the Argillaceous, 

 or Metal Stone strata, are shaded dark ; the seams of Coal are repre- 

 sented by black lines ; as are also the Slip Dykes, and the alluvium is 

 represented by a brown shade. The sea-level high water-mark is shewn 

 by a strong dotted line on each section. 



No. 1, Plate XXI. Is a section of the strata from the deepest point, ( 1 80 

 fathoms), to which the Main Coal Seam has been worked, under Jarrow 

 Slake, to the Holywell Pit on the north side of the Main Dyke. Its ge- 

 neral line of direction is nearly north and south, cutting the Main Dyke 

 nearly at right angles, a little to the north of Prospect Hill, on Shire Moor. 

 This section shews the strata from the Low Main Seam upward, as far 

 as it can be ascertained, by actual sinkings and borings, and by 

 analogy, but a space of about 55 fathoms, including the alluvium under 

 Jarrow Slake, still remains unexplored and unknown. At this lowest 

 point we have nine separate strata of Sand Stone of various thickness, 

 divided by eight groups of Metal Stone of various colour and texture, 

 but the divisions of which cannot be represented on so small a scale. 



The following Sand Stone strata, shewn at this point of the section, 

 are the only ones which are distinctly recognizable through every part 

 of the Coal Field, viz. : — The Main Post, the Seventy Fathom Post, in 

 two or three divisions, and the Grindstone Post. Above the Grind- 



