a. Aspect of a 5-ha hard playa between Rosamond and Rogers Playas, Califor-
nia, a few weeks after inundation and subsequent drying. Note polygons (lower
left), drift lines running from left center to left bottom, and algal crusts with
upturned ends (center).
b. Hard playa/upland transition. Note upland (pedi-
d. Edge of hard playa with concentric drift lines (left)
cillated) cryptobiotic crusts (right edge center) grad-
and thick, stratified crusts (right) showing at least
ing into smooth cryptobiotic crusts (right bottom),
two generations of cracking. Also note vegetation
drift marks, debris lines, and small polygons.
c. Large, flat, polygons indicative of inundation on
e. Hard (non-algal) crusts from the lowermost por-
large playas as found at Rosamond Dry Lake, Cali-
tion of a 2-ha hard playa. The surface is smooth,
but with vesicular pores, the edges are strongly up-
turned, and there is very conspicuous layering.
Figure 3. Aspects of a hard playa.