in thickness can be found on the Canadian Prairies, Poland, England, Denmark and Sweden. One erratic megablock located in Saskatchewan is (and up to thick). Their sources can be identified by locating the bedrock from which they were separated; several rafts from Poland and Alberta were determined to have been transported over from their source. Nonglacial erratics In geology an erratic is any material which is not native to the immediate locale but has been transported from elsewhere. The most common examples of erratics are associated with glacial transport, either by direct glacier-borne transport or by ice rafting. However, other erratics have been identified as the result of kelp holdfasts, which have been documented to transport rocks up to in diameter, rocks entangled in the roots of drifting logs, and even in transport of stones accumulated in the stomachs of pinnipeds during foraging. History During the 18th century, erratics were deemed a major geological paradox. Geologists identify erratics by studying the rocks surrounding the position of the erratic and the rock of the erratic itself. Erratics were once considered evidence of a biblical flood, but in the 19th Century scientists gradually came to accept that erratics pointed to an ice age in Earth's past. Among others, the Swiss politician, jurist and theologian saw glaciers as a possible solution as early as 1788. However the idea of ice ages and glaciation as a geological force took a while to be accepted. Ignaz Venetz (1788–1859), a Swiss engineer, naturalist, and glaciologist was one of the first scientists to recognize glaciers as a major force in shaping the earth. In the 19th century, many scientists came to favor erratics as evidence for the end of the Last Glacial Maximum (ice age) 10,000 years ago, rather than a flood. Geologists have suggested that landslides or rockfalls initially dropped the rocks on top of glacial ice. The glaciers continued to move, carrying the rocks with them. When the ice melted, the erratics were left in their present locations. Charles Lyell's Principles of Geology (v. 1, 1830) provided an early description of the erratic which is consistent with the modern understanding. Louis Agassiz was the first to scientifically propose that the Earth had been subject to a past ice age. In the same year, he was elected a foreign member of the Royal Swedish Academy of Sciences. Prior to this proposal, Goethe, de Saussure, Venetz, Jean