As spring progresses, the glacial ice melts rapidly but unevenly. The fastest melting is where a thin layer of rock gravel, which is dark and warms rapidly in the sun, covers the ice. The slowest melting occurs under big rocks, which act as a blankets, or uncontaminated ice, which acts as a reflector. By now, many of the larger boulders are left standing on ice pillars, the surrounding ice having melted away, and look like large mushrooms. — Charles Corfield