of the creek and the river, we came on a dyke of basalt, the
flat summit of which was so rough that we were compelled to travel along
the flats of the creek, which for a long distance ran parallel to the
Burdekin. The soil on the basalt was so shallow that it sustained only a
scanty vegetation of grass and some few scattered narrow-leaved Ironbark
trees. We crossed this dyke, however, and at about three miles descended
from it into a fine narrow-leaved Ironbark flat, extending along the
river, in which another large creek from the south-west joined the
Burdekin. The flat was bounded by hills of limestone, cropping out in
large blocks, with visible stratification, but without fossils. Having
passed the third creek in the course of this day's journey, we encamped
on the commencement of another basaltic dyke. The bed of the creek was
full of blocks of Sienite, of hornblende Porphyry, of greenish Pegmatite,
and of cellular Basalt. The river here formed a large sheet of water;
large masses of a white Sienite protruded out of it, opposite the
junction of the creek. The opposite bank exhibited a very perfect and
instructive geological section of variously bent and lifted strata of
limestone, which was afterwards found to contain innumerable fossils,
particularly corals and a few bivalve shells. The Rev. W. B. Clarke, of
Paramatta, kindly undertook to examine the fossils brought from this
locality. One he determined to be an undescribed species of Cyathophyllum,
and has done me the honour to give my name to it [Refer Note 1 at end of
chapter]. The others belonged principally to the following genera, viz.,
Asterias, Caryophyllea, and Madrepora. The right bank of the river rose
into steep cliffs of basalt, under which the clustered fig tree, with its
dense foliage, formed a fine shady bower. The basaltic dyke was about a
mile and a half broad, and I followed it about five miles up the river.
Its summit was flat, rough, and rocky; at the distance of four miles from
our camp it receded a little from the river, and there limestone was
observed, crowded with fossils like that on the opposite side of the
river. Two miles farther, the bed of the river was formed by a felspathic
rock, with beautiful dendrites. A small island, with a chain of lagoons
on one side, and with the river on the other, was also composed of this
rock, in contact with, and covered by, basalt in several places. There
were small falls and rapids in several parts of th