130 
atratum of rock, from 80 to 40 feet in thickness, exists, called 
“ Crease,”’ in which the great deposits of Hematite iron-ore of 
the district occur. 
This “Crease”? consists principally of silica and limestone, 
is rough in texture, and frequently streaked with a reddish 
colour. 
The particular bed of rock upon which the iron-ore is 
deposited is from 3 to 15 feet in thickness, and is very compact 
and highly crystalline. Iron-ore is never found below this 
rock unless cross joints exist in it. This base of the iron-ore 
measures is locally called ‘‘Underedge.” From this point 
downward, the great mass of the Carboniferous Limestone com- 
mences, consisting of a series of hard compact beds of varying 
thickness, and of an imperfectly formed crystalline character. 
The general colours are mixtures of red, brown, and grey; the 
red colour, however, predominates in the upper and thicker 
beds down to the first shales. 
In the Memoirs of the Geological Survey, Vol. I., p. 128, a 
section of the Carboniferous Limestone is given, and is said 
to have been obtained from near Lower Purlien. It is as 
follows :— 
SECTION No. 1 
Totals in 
Thickness tt ai 
Description of Measures ge once iene 
inches | e020 
ft. in.”| ft. “ine ieee 
Marl us eal) NG 
Gray impure and sandy limestone... Ah owe) 
Mar! wee Be ewe ate ne ees|) O28 
Impure limestone... ine Soc ag wach wagon) 
Mar! seal) ol sO) 
Red sandstone, with calcareous matter.. 2 ./ <9-n0 
Marl me bas sas a gOe 3S 
Gray and red sandstone . 21770 
Sandstone, with intersir atified beds of shale . Bef KU 
Red and soft sandstone ... wee|' 20" 10 
Soft sandstone, with thin beds of of clay... eee OP 0 
Hard sandstone ... Sach Leen, 
Sandstone, red with hematite veins... «| 49 0 193 10 | 193 10 
White, gray, and red limestone.. 90) 0 
Limestone, with intermingled hematite exten- 
sively worked ... 56 ae 5p ...| 60 0 
