100 THE HAWKESBURY SANDSTONE. a 
first in stating that the dip of the lamine is frequently as high ss 
45°, and, secondly, in referring them to disturbances of the sa 
during storms in which “the bed of the ocean is heaped up during 
gales into great ripple-like furrows and depressions, which ar 
afterwards cut off by the currents during more tranquil weather, 
and again furrowed during gales.” For my own part, I have » 
doubt that this lamination is in general caused by the flow of walt 
carrying sandy or other detritus from one level to another. As 
the grains fall over the verge they arrange themselves nS 
beds, descending to the lower level. This slanting front is mme 
diately covered by another thin course, dipping at the same angle 
This process I have often watched in the sands of Mo Bay. 
Tt is, in fact, this drift of wind-and-water-shifted sands The 
changes with such rapidity the river courses in that estuary, —" 
channels are continually but gradually altering at every Lee 
the principal cause of their sudden and dangerous alterations S 
believe, the action of the wind on very thin sheets of ppc 
ing very quick sands. And the layers so deposited are, W" 
solidified, the laminz of the oblique or cross or false sua 
= — we have such abundant illustration in the Hawkesbury 
eds, er 
The broad band of red stone exposed in the upper cating 
the second Zigzag deserves further investigation. I do not PY 
sume to question Mr. Tenison-Woods’ views as to its tH 
but only to indicate that it appears to form a dist ib jee 0 | 
that in the latter case, at least, it marked the passage ep i | 
Hawkesbury beds is their principal feature THF tye 
ck and thin out there, and their surfaces 
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