Perhaps Isenberg should submit his work for publication. Until then, however, I accept the findings from a peer-reviewed paper by MGS TES team members that appeared in the October 25, 2002 (MGS
Special Issue) of JGR-Planets:

Ruff, Steven W. ; Christensen, Philip R. ; Clark, Roger N. ; Kieffer,
Hugh H. ; Malin, Michael C. ; Bandfield, Joshua L. ; Jakosky, Bruce
M. ; Lane, Melissa D. ; Mellon, Michael T. ; Presley, Marsha A. 2001

Mars' "White Rock" feature lacks evidence of an aqueous orgin: Result
from Mars Global Surveyor

J. Geophys. Res. Vol. 106 , No. E10 , p. 23,921 (2000JE001329)

Abstract:

The "White Rock" feature on Mars has long been viewed as a type
example for a Martian playa largely because of its apparent high
albedo along with its location in a topographic basin (a crater).
Data from the Mars Global Surveyor Thermal Emission Spectrometer
(TES) demonstrate that White Rock is not anomalously bright relative
to other Martian bright regions, reducing the significance of its
albedo and weakening the analogy to terrestrial playas. Its thermal
inertia value indicates that it is not mantled by a layer of loose
dust, nor is it bedrock. The thermal infrared spectrum of White Rock
shows no obvious features of carbonates or sulfates and is, in fact,
spectrally flat. Images from the Mars Orbiter Camera show that the
White Rock massifs are consolidated enough to retain slopes and allow
the passage of saltating grains over their surfaces. Material appears
to be shed from the massifs and is concentrated at the crests of
nearby bedforms. One explanation for these observations is that White
Rock is an eroded accumulation of compacted or weakly cemented
aeolian sediment.