ice margin
-9999
Retreatal position of stagnant-ice margin
meltwater channel
Meltwater channel
meltwater spillway
Meltwater spillway
questionable synglacial sea maximum
Generalized max extent of late Wisconsinan synglacial sea
synglacial sea maximum
cross section
Cross-section line
gravel pit extent
Extent of large pits in surficial materials
Null value