1815.) Account of the Sunderland Lime-stone Formation. 117 
The lime-stone of this stratum has been much in request for the 
sculpture of coats of arms for mansion-houses. 
The fourth stratum of lime-stone is worked to the depth of 17 
feet, and is the lowest at present wrought. 1 shall have occasion to 
offer some remarks afterwards at the conclusion of this paper, when 
I shall mention the depth of this stratum where it was worked 
through in sinking a coal-pit shaft. The colour of this stratum is 
bluish-grey ; it is massive ; fracture conchoidal ; fragments sharp 
edged; translucent upon the edges; cannot be scratched by the 
nail, though readily enough by fluor spar; it is hard, and not 
readily frangible ; contains not more than five per cent. of mag~ 
nesia. 7 
About two feet from the bottom of the quarry, this stratum be- 
comes so fine in the texture that. it has been sculptured for orna- 
mental purposes, and is well known under the name of the Pallion 
marble. 
The Pallion lime is much valued, and is very extensively used for 
agricultural purposes along the whole eastern coast of England and 
Scotland. An observation of the late Dr. Anderson, in his excellent 
Essays on Agriculture, is so much in point, that I shall offer no 
apology for transcribing it :—“ The only extensive lime-quarries of 
such a pure lime-stone that I have met with are at Sunderland, in 
the county of Durham,” 
The Pallion lime-stone, generally speaking, is hard; but when. 
burnt, it is as light and soft to the touch as chalk-lime. ‘This lime- 
stone accordingly loses much weight by calcination, and requires a 
large proportion of water to slake it. 
In the year 1787 a coal shaft was sunk about half a mile south- 
west of the Pallion quarry, and upon the same estate. The same 
order and appearance of the strata were observed as in the Pallion 
quarry, that is, as far down as the latter quarry is worked, which is 
to the extent of 17 feet in the fourth stratum of lime-stone, as 
mentioned above. After this the shaft was carried through 64 feet 
of blue Jime-stone, which became coarse, and of inferior value. 
Immediately below this stratum of lime-stone the shaft was 
worked through a stratum of dark slate-clay alternating with blue 
slate-clay, which was 240 feet in depth. The shaft was next passed 
through a mass of green-stone (the whin-stone of this county) and 
elay-slate to a considerable depth, 
Mr. Goodchild has lost the memoranda which were taken when 
the shaft was sunk; but you may rely upon the accuracy of the 
above statement, as I had it from himself. 
Iam, dear Sir, your faithful friend, 
W. Resp Cranny, 
