Retrogressive thaw flow slides involving thin beach gravels over till
Location:
Near
Kaminak Lake, Nunavut, Canada;
NTS 55L;
62°17'N, 95° 13'W
Normally sandy/gravelly, near-shore sediments are not involved in solifluction, but in this unusual example, the 0æ isotherm has descended into underlying till, causing segments of this raised marine beach complex to founder in and mix with underlying, clay-rich red till to form a complex of mudboil-covered solifluction lobes. The resulting homogenized mass is moving downslope, probably as a retrogression thaw flow slide (see images 0218, 0219). The scar of an earlier, apparently stabilized slide can be seen cutting the beaches at the upper left. The beaches were formed as this area emerged, as a result of glacioisostatic uplift, from the postglacial Tyrrell Sea, about 4000 years ago.
Updated 08/28/2009 CAB