Beaches formed on "Hill 575" at maximum level of submergence of the glacio-isostatically depressed landscape in the post-glacial Tyrrell Sea. This hill, with a crest at about 175 m, formed a small offshore island in the Tyrrell Sea approximately 6,600 years ago. The mudboil-covered till surface (see explanation for Image 0240) is actively moving down slope over the highest beaches, forming a solifluction front about 2 m high. The front of the soliflucting till mass bisects the photo. The rock bursts depicted in Images 0050, 0111, and 0112 are above this till/beach contact on "Hill 575." Image 0236 shows another view of the beaches and of the solifluction escarpment. This soft sediment flow of the active layer tends to flatten the landscape and is one of the processes associated with cryoplanation. In this case, the covering of the highest beaches makes it difficult to determine the precise altitude of the limit of marine submergence.