GLACIAL BOULDERS—CENTRAL AUSTRALTA. 1138 
This evidence is in the form of erratics, up to 2 cubic feet in 
capacity, sporadically distributed, or occurring in groups, in the 
marine Permo-Carboniferous strata of the above coal-tield. As 
however, none of the blocks hitherto found, exhibit glacial strie, 
their glacial origin cannot, as yet, be said to have been demon- 
strated. Mr. Jack has suggested as a possible alternative expla- 
nation of the phenomena, that the blocks may have been entangled 
in roots of floating trees, and have been subsequently dropped 
from them. On the whole, however, the theory that they are ice- 
borne, appears to us to afford a far more satisfactory explanation. 
Mr. Jack states that in his middle, or marine, subdivision of 
the Bowen series, the remains of trees are neither numerous nor 
large (and this is the horizon to which the erratics belong), while 
in the Upper Bowen Series (freshwater), which may be correlated 
with the Newcastle Series of New South Wales, silicified tree 
trunks of very large dimensions (up to 3 feet in diameter, and 
over 40 feet long) are astonishingly numerous, and lie horizontally 
embedded in the sandstone, which is suggestive of their drift 
origin. The horizon of the drift timber, therefore, does not coincide 
with the horizon of the erratics, another fact in favour of the 
latter being ice-borne. 
In the Northern Hemisphere traces of glacial action have been 
met with even nearer the Equator than Crown Point or the Bowen 
River Coal-field. Near the village of Trai, in Southern India, 
striated and grooved rock pavements have been described by 
Fedden, in latitude 19° 53’ N., at an elevation of 900 feet above 
the sea. The Talchir boulder beds, in which erratics up to 30 
tons in weight are embedded, extend to latitude 17° 20’ N. 
V. Summary. 
The discovery by Professor Spencer and Mr. P. M. Byrne, of 
undoubted glaciated pebbles at Yellow Cliff, may therefore throw 
important light on the extent Equatorwards of the carry of 
glaciated rocks, possibly in Permo-Carboniferous time, unless the 
glaciated blocks are the result of some local glaciation in Central 
Australia, at some later period. It presents another inviting 
tield of research among the many opened up by the Horn 
Scientific Expedition. 
More observations are now urgently needed to show the strati- 
graphical relationships of the glacial pebbles, particularly to the 
Desert Sandstone. The Glacial Committee desire to express their 
thanks to Professor Spencer and Mr. P. M. Byrne, for kindly 
placing their interesting collection and notes at the disposal of the 
Glacial Committee. 
