50 
SHAPES AND FEATURES OF AUSTRALITES 
edges. It appears to have been originally boat-shaped and to have 
been reduced to its present shape by selective flaking and abrasion. 
Pig. 15. (Plates XII and XIII.) A fragment, approximately one third of a 
flange; on the posterior surface is a gas blister, mm. across, marked 
b in fig. 15, Plate XII, an unusual feature on flanges. The thin glass 
film covering this bubble has been distended by the enclosed gas. No 
similar bubbles have been noted in other flanges examined, although 
larger bubbles are not uncommon in cores. Most bubbles in flanges 
have burst and are represented by small pits or craters (see fig. 15, 
Plate XII). Locality: Near Sentinel Rock, 1^ miles east of Port 
Campbell. 
Plate XIII 
Pigs. 16 to 30. Posterior surfaces of flanges detached from the cores of button- 
shaped or oval (figs. 17, 28) australites by clean natural fractures. 
The posterior surfaces are smooth, except for occasional small bubble 
craters, but fine concentric flow lines can be observed under higher 
magnifications. The anterior surfaces are usually flow-ridged. Pew 
examples of such complete flanges have been recorded in the extensive 
literature on australites. 
One fragment of a thin flat-topped flange (fig. 24), is exceptional 
in having both the posterior and the anterior surfaces rough. 
Pig. 30 represents portion of an unusual, thin, broad type which 
carries eight shallow, elliptical bubble craters on its posterior surface; 
five form a cluster (in the bottom part of the photograph) and two 
others have coalesced. A remnant of the core attached to the fragment 
is distended by the escape of a large gas bubble, originally at least 
10 mm. across. Such a form would be very prone to fragmentation. 
The bases of the bubble craters on the flange fragment are marked by 
occasional flow lines and minute bubble pits. Between the bubble pits, 
the glass of the flange is also flow-lined. 
The outer and inner rims of flanges in Plate XIII are generally 
smooth, but their continuity is sometimes interrupted by small bubble 
craters (fig. 21). Wrinkled flow ridges at the equators of anterior 
surfaces occasionally cause the outer to be le.ss symmetrical than the 
inner edges (figs. 28, 29). The truncated portion at the bottom of 
fig. 26 is caused by a fracture. 
Localities : Prom between half and 5| miles east of Port Campbell, 
except No. 22, which came from near Marble Arch, 3 miles west of 
Port Campbell. 
Plate XIV 
Pigs. 31A and 31B. A flange fragment embedded in sandstone of Recent age, 
overlying post Miocene clays; the cementing medium in this rock is 
argillaceous. The specimen came from a steep slope near the cliff edge 
in a small bay north of Gravel Point, 2| miles east of Port Campbell. 
The sandstone forms a hard band a few feet thick below 4 feet of clay 
and surface soil. 
Australites iisually occur on wind-blown or rain-swept surfaces, or 
have been washed out of loose, incoherent deposits. The only other 
record of an australite in consolidated rock is a specimen from Gawler, 
South Australia (Tate, 1879) ; it was enclosed in a travertine nodule 
forming part of the Recent crust limestone in that area. 
