File name: USGS_Precambrian_dropstone_620.jpg
Original Resolution: 620 × 413
File Size: 294 KB (MIME Type: image/jpeg)
Found near Whitefish Falls, Ontario, along the northern shore of Lake Huron, this dropstone landed in seafloor sediments under a floating glacier some 2.2 billion years ago. Image from Precambrian Time—The Story of the Early Earth, photo by D.A. Lindsey, USGS.