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 0° 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 retrogressive 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. These beaches were formed as this area emerged, as a result of glacioisostatic uplift, from the postglacial Tyrrell Sea, about 4,000 years ago. See detailed discussion for image 0240.

Updated 05/06/2010 AW