24 
The Queensland Naturalist. 
May, 1927 
STREAMiS AND THEIR PAST. 
(By Dr. E. 0. Marks.) 
{Presidential Address delivered before the Queensland 
Naturalists’ Club, 21st February, 1927.) 
Who has not regarded with admiration and wonder 
a mountain range, or some isolated peak? How beautiful, 
how grand, how enduring those ‘ 4 everlasting” hills. Yet 
it is a commonplace of geologists that these everlasting 
hills are really the most evanescent features of the lands- 
cape, and are, generally speaking, much younger than the 
streams. Earth movement, shall we call it 4 'some convul- 
sion of nature,” may elevate a plateau or mountain mass, 
but the carving of it into the mountain and valley, as we 
know them, is the work of water. Tennyson’s talkative 
brook should have said: "Hills may come and hills may 
go, but I go on for ever, carrying away their debris until 
there is nothing left to carry.” In a sally, or perhaps a 
bickering, it might even have uttered the jibe: "What 
ailed ye ye mountains that ye skipped like rams and ye 
little hills like lambs?” 
To be more serious, the streams are usually the oldest, 
as they are certainly the most active, and therefore really 
the predominant feature of the land surface. 
They have a history which has probably left its mark 
upon them, so that a consideration of their various 
characters may possibly yield information not otherwise 
obtainable about their own former condition, and the 
land surface over which they originally flowed. 
Before discussing some of the features of the streams 
in this corner of the State, we iiiust first consider the 
manner in which a stream acts in carving the landscape. 
Let us suppose that a land mass is suddenly raised 
above the sea and exposed to the weather The surface 
cannot be absolutely flat, the rain water will collect in the 
hollows, however slight, and find its way to the edge over 
which it will fall into the sea. Quickly the nascent stream 
will cut back into the edge of the plateau, forming first 
a cataract and then a gorge. This must of necessity 
follow up the stream which is doing the cutting, and so 
must come to occupy more or less closely the original 
depression in the surface. 
In the process the original waterfall, with all the 
fall in one place, becomes a cataract, then a torrent, and 
