Cketaceous Stratigraphy of Lower Murchison River Area, 
Western Australia. 
29 
exposed, is clearly detined by a succession of well-bedded reddis.h and 
white sandstones and the contact with the overlying imbedded, incoherent 
lower part of the Unite Sandstone is sharp and well marked. 
L'itholog }}. — Seen from a distance outcrops of tli(‘ Tiunblagooda Sand- 
stone have the appearance of l)eing very Ibick-bedded, with bedding 
])lancs ten or twenty or more feet apart, but closto- insj>eetion shows 
that nearly all ther,e thick beds are eery strongly and irregularly 
cross-bedded (text tig. 8). The bulk of the sandstone is reddish to ])urpiish 
in colour, but in many ]>laces, where it is very finely laminated, white 
layers alternate with red. (hi the whole the sandstone is medium-grained 
Text Fig. 8. 
Typical Tumblagooda , Sandstone near foot of east side of 
Tumblagooda showing cross-bedding and (aho\’e and to right of 
pick) worm burrows. Honeycomb structure in upper right cornei 
is due to weathering, not to worm burrows. 
with grains up to 1 or 2 mm. diameter. The components are predomin- 
antly quartz grains. Bands of pebbles of varying sizes, up to 1 or 2 
cm. diameter are not uncommon, but larger pebbles of several centimetres 
in diameter are rare. Many of these large pebbles are surrounded by 
