Head and Marchant have written further on their theory that glaciers existed during periods of high obliquity in Tharsis and that relict ice may still exist there:

COLD-BASED MOUNTAIN GLACIERS ON MARS: WESTERN ARSIA MONS FAN-SHAPED DEPOSITS: J.W. Head1 and D.R. Marchant2; 1Dept. of Geol. Sci., Brown Univ., Providence, RI 02912 USA; 2Dept. of Earth Sciences, Boston Univ., Boston, MA
02215 USA.
Lunar and Planetary Science XXXIV (2003) 1247.pdf
"The sharp ridges at the head of major lobes on
Arsia Mons imply active flow and suggest the presence of buried
glacier ice [4]."
http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1247.pdf

COLD-BASED GLACIERS IN THE WESTERN DRY VALLEYS OF ANTARCTICA: TERRESTRIAL LANDFORMS AND MARTIAN ANALOGS: David R. Marchant1 and James W. Head2, 1Department of Earth Sciences, Boston University, Boston, MA 02215 marchant@bu.edu, 2Department of Geological Sciences, Brown University, Providence, RI 02912
Lunar and Planetary Science XXXIV (2003) 1245.pdf
"Martian analogs: An Amazonian-aged deposit covering
~180,000 km2 of the western flank of Arsia Mons displays several
features diagnostic of deposition from cold-based ice (details are
outlined in [2]). Foremost are: 1) an outermost zone of over 100
arcuate and parallel raised ridges (drop moraines), each up to 10
meters high and 100 km long; 2) a medial zone of rough,
hummocky topography (sublimation till) superposed on intact
lava flows; and, 3) a proximal zone abutting the upper flanks of
Arsia consisting of several individual lobes and superposed
parallel raised ridges. The latter closely resemble terrestrial rock
glaciers. None of the deposits are associated with geomorphic
features indicative of meltwater. Collectively, these features
suggest glaciation of western Arsia Mons and open up the
possibility that relict glacier ice may remain there in extant rock
glaciers."
http://www.lpi.usra.edu/meetings/lpsc2003/pdf/1245.pdf

Debris on Martian equator hints that Mars once had ‘cold-based’ glaciers like those at Earth’s poles
http://www.brown.edu/Administration/George_Street_Journal/vol27/27GSJ10d.html

Current glaciers in Tharsis?
Posted by Robert Clark (68.81.141.219) on 11/23/2002 7:26:23 AM
http://habitablezone.com/space/messages/26942.html

Bob Clark