At tie Monkland tie bed of impure limestone wiici lies at tie top of tie auri- 
ferous series “is considerably over 200 feet thick (probably about 230 feet). It can be 
seen in the high northern bank of the river close to the small gully on the No. 2 Great 
Eastern ground, but beyond that point I have been unable to trace it in a southerly 
direction. The conglomerate that underlies the limestone is exceptionally thick where 
the section-line crosses it. It is made up of pebbles ranging from I inch up to 8 inches 
in diameter, and consisting chiefly of greywacke, sandstone, and quartz. In places 
it passes into sandstone. 
“ I now come to the consideration of the beds of ‘Black Slate,’ in connection with 
which the richest deposits of gold have been found in the reefs. In the true sense of 
the term these beds are ‘ shales,’ and not ‘ slates,’ the fissility or lamination coinciding 
with the planes of bedding. 
“ The shales are at times laminated, sometimes thin-bedded, but generally thick- 
bedded. They pass in places into aluminous sandstone, locally called ‘ Black Eock.’ 
The shales are carbonaceous, slightly calcareous (their joints are always coated with 
calcite), and generally they are pyritous. Thin sections examined under the microscope 
show them to be made up of fine carbonaceous mud, with small rounded and a few 
semi-circular specks of quartz and small cubes of iron pyrites. 
“ There are four well-defined zones of slate. The uppermost one, which may 
be termed ‘ Phosnix or Monhland Slate,’ is about 200 feet thick ; in it there are a 
few thin beds of sandstone and greywacke. By far the greater part of the gold 
has been taken from the reefs when passing through this bed, in which fossils are 
very numerous, the commonest forms being — Fenestella, Proforetepora, Spirifera, 
Produetm cora, Stropliomena rhomhoidalis, Aviculopecten, Pleurotomaria earinata, and 
Orthooeras. 
“ The next beds of auriferous shale in descending order are what have been 
termed by the miners the '■First and Second Beds of Slate.' These beds vary from 
10 to 20 feet each in thickness, and are about 100 feet or more vertically apart. They 
are rich in iron pyrites, and are generally of a fissile structure. On weathering, they 
become friable and brown in colour, owing to the amount of ferruginous matter in 
their composition. Very rich deposits of gold have been obtained from reefs in 
contact with these shales, especially during the early days of the field. The Lady 
Mary, Caledonia, California, New Zealand, Crown, March, Hilton, and Hamburg Eeefs 
carried rich gold in these beds. So far as my observation went, these two beds are 
not fossiliferous. 
“The ' Third Bed of Slate' lies about 400 feet below the second. It is quite 
different in its character from that of the three zones lying above. It is always, too, 
associated with a greenish-grey, fine-grained, laminated greywacke, possessing a flinty 
or splintery fracture. This greywacke is of great thickness. The Ellen Harkins shaft 
has passed through over 300 feet, and the Wilmot shaft about 200 feet of it. Thin 
sections of this greywacke show, under the microscope, a very fine-grained ground-mass, 
with small rounded and subangular particles throughout it. Beds of the black carbon- 
aceous shale occur at various depths in this greywacke, three such layers occurring in 
the Ellen Harkins ; but besides these distinct beds there are patches of a black rock in 
it, which, under the microscope, show a similar structure to the greywacke ; it is in fact 
a black carbonaceous greywacke, the one rock passing insensibly into the other. The 
whole thickness of groyw'acke and shales forms the fourth auriferous zone, and is known 
on the field as the ‘Third Bed of Slate.’ The gold m this bod is exceedingly patchy, 
and many claims have been working on it without success. It was, however, in this 
shale, at a depth of 600 foot, on the Ellen Harkius Keef, that perhaps the richest patch 
