22 
FLANGES OF AUSTRALITES (TEKTITES) 
5. Gap a filled ■with ferruginous clay (dark area). Bubble tubes (black 
areas) along line of union c continuous with flow lines in core. 
6. Flow lines parallel in seat, folded towards posterior side of flange 
and contorted in vortical region (dark). Neck inclined; posterior 
surface of flange flat. 
7. Flow lines in seat continuous with those in anterior surface regions 
of core; those in flange deeply folded on posterior side of the vortical 
region. Flow lines in core normal to posterior surface. 
8. Re-enclosed bubble-pits in core occur along the line of union c. 
Flow lines in core have marked trend towards bases of bubble-pits 
opening on its posterior surface. On flange, vortical region of spirally 
coiled flow lines lacking, probably removed by ablation. 
9. Sharp line of union c without bubbles. Seat structure ill-defined. 
Colour banding represented by darker regions in chin and along line 
of union c. Posterior surface of flange concave, 
10. Seat small. Line of union c clearly defined, not associated with bubbles. 
Flow lines normal to surface in chin, line of union c, and base of 
flange. Flow lines spirally coiled in outer edge regions; vortical 
portion of coiling clearly marked. 
11. Re-enclosed bubble-pits along line of union c ; seat sharply terminated 
at lowest flow ridge in flange; ferruginous clay infilling gap a. 
Posterior surface of flange concave with outer edge reduced in thick- 
ness by ablation. 
Plate III 
Fig. 1. Enlarged portion of Fig. 4 (this Plate). Spiral coiling in vortical 
region (black area) obscured by crowding. Flow lines of anterior 
surface truncated in the flow troughs. Tubes of glass of different 
refractive index occur in core near line of union c. 
2. Equatorial section of flange fragment. Outer edge crenulate, inner 
edge smooth. Flow lines in chin region concentric and parallel with 
the inner edge ; in other parts crowded and confused. 
3. Equatorial section of half a flange. Both inner and outer edges 
relatively smooth. Flow lines locally complex, but major trends 
parallel with the outer and inner edges. 
4. Radial section of flange on button-shaped australite, showing bifurcat- 
ing crack infilled with ferruginous clay extending from gap a into base 
of flange. Flow lines pass from anterior surface regions of core into 
seat and coil spirally near outer edge. 
5. Oblique section through junction of flange and core of button-shaped 
australite. Re-enclosed bubble-pits along line of union c. General 
direction of flow lines in flange parallel to c. 
6. Equatorial section of disc-shaped australite (cross section as in Plate I, 
Fig. 8) showing broad flange with concentric flow structures and small 
core with bubble cavity and complex flow pattern. 
7. Equatorial section of button-shaped australite with remnants of 
flange, showing re-enclosed bubble-pits along line of union c and 
complex flow pattern in core. 
