The country over which we travelled about eight miles N. by W., was one of the finest we had seen. It was very open, with some plains, slightly undulating or rising into ridges, beautifully grassed and with sound ground. We crossed the river I had seen the preceding day from the hill, and found it running. Two large creeks, one from the right and the other from the left, also joined the Burdekin. I observed Pegmatite of a white colour, and hornblende Porphyry and Diorite. A shrubby Clerodendron and an arborescent Bursaria, covered with white blossoms, adorned the forest. The latitude was 20 degrees 0 minutes 36 seconds.
April 11.--We continued our journey up the river, in a W.N.W. direction, for about ten miles. The first part of our journey lay through a most beautiful country. The hollows along the river were covered with a dense sward of various grasses, and the forest was open as far as the eye could reach. Farther on, however, we occasionally met with patches of Vitex scrub, and crossed some stony ridges. A small river joined from the north-east, at about a mile and a half from the last camp, and also two large creeks from the south-west. I ascended the hills opposite our camp, and looked over an immense and apparently flat country, out of which small peaks and short ranges rose. The hills on which I stood were composed of Pegmatite, with patches of white Mica in large leaflets. During the journey we found granite changing into gneiss, diorite, and quartz rock.
On the rocky crest of the hill, I gathered the pretty red and black seeds of a leguminous climbing shrub (Abrus precatorius). Phonolithic or basaltic pebbles made me suppose that we were near to a change of country. Our latitude was 19 degrees 58 minutes 11 seconds.
April 12.--We had scarcely travelled a mile and a half, when we had to cross a large creek, which increased in size higher up. Box-tree flats and open Vitex scrub extended along its banks, and the latter, according to Mr. Roper's account, changed into dense Bricklow scrub. At the junction 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 the river. A beaten foot-path of the natives, and many fire-places, showed that this part of it was much frequented by them. Wallabies were very numerous between the cliffs of the felspathic rock; and the fine fig trees along the banks of the river were covered with ripe fruit. The river made a wide sweep round the left side of a large limestone hill, whilst a chain of deep basaltic water-holes continued on its right. The basalt ceased to the westward of the limestone hill, and was succeeded by considerable flats of Ironbark, Moreton Bay ash, and Bloodwood. The Capparis still exhibited a few showy flowers. I examined the country thus far on the 12th April, after the camp had been formed; on returning, I took with me a large supply of ripe figs, of which we partook freely, and which caused several of us to suffer severely from indigestion, though we had frequently eaten small quantities of them without inconvenience.
April 13.--We avoided the field of basalt by moving up the creek we last crossed, about four miles, and by crossing over to the flats of the river where the basalt terminated. These flats, however, were again interrupted by a basaltic dyke, over which we were compelled to travel, as the steep banks of the river were on one side, and black bare rocks, forming sometimes regular walls with a dense scrub between them, prevented us from turning to the other. After descending from the basalt, we crossed a good-sized creek from the south-west, and travelled over a fine open country to lat. 19 degrees 49 minutes 41 seconds.
Two hills were close to the left side of the Burdekin, which, at their base, were joined by a large running creek from the N.N.W. From the limestone hill of yesterday, no other hill was visible to the westward, though ranges and isolated hills lay to the north and north-east, and a high blue mountain to the south-west.
Some days ago I found, for the first time, Spathodea alternifolia (R. Br.), which we continued to meet with throughout the remainder of our journey. I saw but one flower of it, but its falcate seed-vessels, often more than a foot long, were very numerous. Pandanus spiralis was frequent. The box (Eucalyptus), on the flats along the creek, the soil of which is probably formed of the detritus of basaltic rock, had a lanceolate glossy leaf, uniting the character of the box with glossy orbicular leaves growing generally on the whinstone soil of the northern parts of the colony, and of the box with long lanceolate leaves which prefers stiff flats on the tributary creeks of the Hunter. A Bottle-tree with a Platanus leaf (Sterculia?) grew in the scrub on the field of basalt, and was in full blossom. A pretty species of Commelyna, on the flats, a cucurbitaceous plant with quinquepalmate leaves and large white blossoms, grew along the river, the approaches of which were rendered almost inaccessible by a stiff high grass. Charley brought me the long flower-stalk of Xanthorrhaea from some ridges, which were, doubtless, composed of sandstone.
Two kangaroos were seen; they were of middle size, and of a yellowish grey colour, and seemed to live principally about the basaltic ridges.
The cooee of natives had been heard only once during our journey along the banks of the Burdekin; and the traces of their former presence had not been very frequently observed. Large lagoons full of fish or mussels form a greater attraction to the natives than a stream too shallow for large fish, and, from its shifting sands, incapable of forming large permanent holes. Wherever we met with scrub with a good supply of water, we were sure of finding numerous tracks of the natives, as game is so much more abundant where a dense vegetation affords shelter from its enemies.
April 14.--Last night, at seven o'clock, a strong breeze set in from the northward, and continued for about an hour, when it became perfectly calm. If this was the same breeze which we had observed at the Mackenzie at eight o'clock, and which set in earlier and earlier, as we travelled along the Isaacs and Suttor (though it was less regular in these places) until we felt it at about six o'clock, we were now most evidently receding from the eastern coast.