28 
Report of the Expedition 
whole country is composed of granite and sienitic rock. Pegmav 
tite and hornblende rock are frequent. At 19 deg. 58 min. ) 
first observed basalt. At 19 deg. 54 min. a fine limestone, with 
many fossil corals, crops out; but higher up the river basaltiq 
ridges are prevailing, which are several times interrupted by quart* 
porphyry (latitudes 19 deg. 18 min. 6 sec. to 19 deg. 13 sec.). 
Both rocks seem to have broken through talcschist, sandstone, 
and conglomerate. 
In latitude 18 deg. 48 min. 9sec. we entered into a large valley 
with numerous lagoons, at the east side of which the river came 
down, whilst a reedy brook swept along the basaltic ridges, which 
bounded it to the southward. The lagoons were covered by 
Nymphsea (the lotus,) the seed vessels and rhizomee of which 
formed the principal food of numerous black fellows. I called this 
country the “ Valley of Lagoons,” or the “ Country of the Loto- 
phagians.” After ascending the basaltic ridges, which surrounded 
the valley to the south, the west, and north-west, we found our¬ 
selves on a level country, openly timbered with narrow-leaved 
iron-bark, or box, the forest changing, with fine plains, sometimes 
many miles long and several miles broad. Often a small brook 
was running in them. To a very conspicuous mountain on the 
basaltic table land I gave the name of “ Mount Lang.” 
A big creek sweeps along the east and north-east side of this 
plateau, and separates it from primitive formations. The frequency 
of big fantastic hills of the white ant, which I had not seen before 
of such a size, induced me to call it “ Big Ant-hill Creek.” At 
latitude 18 deg. 16 min. 37 sec., running brooks came down 
along the plains of the table land from Mount Lang, and several 
other isolated hills, and join Big Ant-hill Creek. In leaving the 
Burdekin I followed up this creek, passed in a north-north-west 
direction over a level country, and came in latitude 18 deg. 22 
min. 2 sec. on waters which flowed to the east and north-east. 
They either belong to the Burdekin or to a more northerly system. 
I called the first creek I came to “ Separation Creek,” as it sepa¬ 
rated the basaltic from the primitive formations, as Big Ant-hill 
Creek had done. Several other creeks joined it lower down. 
Fine flats extend along its banks. The whole table land is beau- 
