The ground on the summit is full of caves of great depth, but there has been a difficulty in examining them, in consequence of the violent wind that rushes up them, and extinguishes every torch.
The open and grassy forests of Argyle are terminated by another of those abrupt sand-stone passes I have just described, and the traveller again falls considerably from his former level, previously to his entering on Yass Plains, to which this pass is the only inlet.
From Yass Plains the view to the S.and S.W.is over a lofty and broken country: mountains with rounded summits, others with towering peaks, and others again of lengthened form but sharp spine, characterise the various rocks of which they are composed.

The ranges decline rapidly from east to west, and while on the one hand the country has all the appearance of increasing height, on the other it sinks to a dead level; nor on the distant horizon to the N.W.is there a hill or an inequality to be seen.
From Yass Plains to the very commencement of the level interior, every range I crossed presented a new rock-formation; serpentine quartz in huge white masses, granite, chlorite, micaceous schist, sandstone, chalcedony, quartz, and red jasper, and conglomerate rocks.
It was however, out of my power, in so hurried a journey as that which I performed down the banks of the Morumbidgee River, to examine with the accuracy I could have wished, either the immediate connection between these rocks or their gradual change from the one to the other.

I was content to ascertain their actual succession, and to note the general outlines of the ranges; but the defect of vision under which I labour, prevents me from laying them before the public.
CHARACTER OF THE SOIL CONNECTED WITH GEOLOGICAL FORMATION.
From what has been advanced, however, it will appear that the physical structure of the southern parts of the colony is as varied, as that of the western interior is monotonous, and we may now pursue our original observations on the soil of the colony with greater confidence.
In endeavouring to account for the poverty of the soil in New South Wales, and in attributing it in a great degree to the causes already mentioned, it appears necessary to estimate more specifically the influence which the geological formation of a country exercises on its soil, and how much the quality of the latter partakes of the character of the rock on which it reposes.

And although I find it extremely difficult to explain myself as I should wish to do, in the critical discussion on which I have thus entered, yet as it is material to the elucidation of an important subject in the body of the work, I feel it incumbent on me to proceed to the best of my ability.
I have said that the soil of a country depends much upon its geological formation.

This appears to be particularly the case in those parts of the colony with which I am acquainted, or those lying between the parallels of 30 degrees and 35 degrees south.