This is a no longer a medial moraine, but now a kame (the sandy and rocky crest) and kettle lake. The kame is composed of sand, gravel, rocks and boulders. It was gradually formed by running water from the melting of Dinwoody glacier, which carried intense amounts of debris into this depression of the retreating glacier. The debris overwhelmed the medial moraine photographed by Mark Meier in the prior image. It also buried one or more detached blocks of glacial ice of the terminus . As the detached ice melted, it rounded and formed a rounded depression, that then filled with water from the meltwater streams.
Finding the vantage point of Mark's photo was difficult, since the moraine has changed so much in the intervening seventy plus years. Mine is close to his vantage point based on the alignments of the only fixed points, the background mountains (West and East Sentinel, and connecting them Chimney Rock). Mark probably took his photo from a lower position to the right of mine, now under the water of a kettle lake.
