42 
In theneigLbourhood of Clermont a ted of dark crystalline limestone crops out close 
to Douglas Creek, about three miles below its junction with Drummond Creek, and about 
four miles south-east of Copperfield. The limestone is full of corals, among which Mr. 
Bands recognised Favosites, Ckaitefes, Cyathophyllum, a compound cyathophylloid resem- 
bling St)'o>nbodes,a.\v\ Stenopora (?), together with a fragment of a Lainellibranch shell.* 
In Marble Island, in the Northumberland Group, a limestone is extensively 
quarried. In some cargoes of this limestone I have seen corals of the species which 
characterise the Burdekin Beds. 
In 1887 1 had an opportunity of visiting Hunter Island, wdiich lies about half- 
a-niile west of Marble Island, in Lat. 21° 58' S. and Loug. 149° 9' E. The island 
extends from north to south about a mile aud a-quarter, and has an average breadth of 
less than a qiuu-ter of a mile. It is w'ell grassed, but the timber is confined to a few 
trees on the beach, among which are some hoop pines. The southern portion of the 
island is joined to the northern by a narrow neck or isthmus, aud is wholly composed of 
granite. In the bay, on the eastern side of the neck, aud in the wide portion of the 
island to the north, a series of stratified rocks make their appearance. They have a 
north-and-south strike, and dip to the east at G5°, being, in all probability, divided by a 
fault from the granite on the south. The uppermost (easternmost) bed seen is a white 
marble at the north end and a blue limestone at the south. Below this, to the west, 
comes a considerable thickness of highly contorted shales or slates, with seams, nodules, 
and lenticular patches of coralline limestone. Next comes a thick bed of blue lime- 
stone, which graduates northward into pink marble. Sandstones aud conglomerates 
underlie the bed last mentioned, and are best exposed in the bay on the east side of the 
isthmus. The last and lowest bed seen is at least 100 feet in thickness. On the east 
side of the isthmus it is an ordinary blue limestone. On the edge of the bay to the 
north, its upper part is white and its base a pink marble. Considerations of wind and 
tide made my visit to the island, in spite of the time consumed in reaching it, a very 
short one, and I had no time to search for fossils. There is no reason to doubt, however, 
that the limestone and other stratified rocks of Hunter Island are of the same age as 
the limestone of Marble Island. The northern end of Marble Island is composed of 
limestones, &c., aud the southern end of granite, so that it is probable that here, as in 
Hunter Island, the stratified and plutonic rocks arc divided by a fault. 
It is noticeable that the northern portions of the outcrops of the three large beds 
of limestone in Hunter Island have become changed from the usual type of blue-grey 
limestone into marble. There is no visible cause for this development of “ regional 
metamorphism,” but it is likely to be due to deep-seated igneous rocks or hydrothermal 
action. As the limestones, &c., were laid down subsequent to the formation of the 
granite, and, where seen, at the southern part of the isthmus, in closest proximity to it, 
are quite unaltered, it is evident that the latter can have had nothing to do with it. 
The western half of the northern portion of the island is composed of granite like its 
southern extremity, and it is probable that the stratified rocks were deposited on the 
granite long subsequent to its consolidation. A mass of diallage-rock is seen on the 
western shore of the island, apparently intrusive through the granite. 
The limestone, of which there is an unlimited quantity, would serve admirably 
for a building stone or for the manufacture of lime. Some argillaceous portions 
would make hydraulic lime. The marble is minutely crystalline and pure white, and 
quite fit for ornamental architoctui'c or statuary. What I have above alluded to as 
“ pink ” marble is a very beautiful stone suffused with a faint blush-rose tint. 
* Report on the Geology and hlmer.al Deposits of the Country in the Vicinity of Clermont. Brisbane ; 
by Authority: 1S86, p. 4 . 
