58 THE HAWKESBURY SANDSTONE. 4 
are built up by the overflow of lava on the summits of this sant- 
stone, and there has been no upheaval. The beds have occasional 
fragments of wood converted into jet, in which the coniferous — 
character can plainly be traced. 
To the west of the main range in Queensland a similar for 
mation is frequently seen—this is Mr. Daintree’s desert sant 
stone. After an attentive examination of its structure, I cannot 
and wherever found the formation is horizontal, and t rock 
that I never could succeed in getting a y of ve | 
thin enough for the microscope. e call 
and friable. But in trying experiments I arrived at nt 
uw 
va small rounded grains of sand cemenuwd together ee 
eous infiltration, in which the facets of small crystals of quartz 
hie; « ' nis “were 
, iliceous. 
fine particles of opaque white, yellow, or brown felspar, 
scales of mica. When powdered, the round grains generally el 
ae while the glassy, transparent, and jagged fragments pence 
the polari 
