Big Rock (glacial erratic)
Big Rock or Okotoks Erratic is an erratic block near Calgary in Alberta, Canada. He is considered one of the largest boulders in the world.
Location and Geology
The geologist James Hector, who examined the rocks in 1863, held it because of its size for the part of an underground mountain range. The Big Rock is an erratic block in the Foothills Erratics Train, a group of thousands of loose behind the other rocks. From erratic blocks is used when they are very large as boulders. The boulders extend in a narrow, about 580 kilometer long belt from the Athabasca Valley to the eastern edge of the Foothills in Montana. Big Rock is located on Highway 7 between the cities of Okotoks and Black Diamond, about 18 kilometers south of the city of Calgary.
The Okotoks Erratic originally consisted of a sedimentary rock, a quartz sandstone of small quartz grains cemented together. This rock had its origin in the Cambrian, namely a period of 542 to 488.3 million years ago. The solidification of the sand created by the pressure of new sediment layers in the flat area of the later Western Interior Seaway Marine. Due to the pressure auflagernder layers and heat the sandstone rock solidified to a new, one quartzite. Quartzites are transforming rocks and among the hardest of stones, as they almost only consist of quartz. The Big Rock is very rugged and provides weathering processes attack surfaces.
History
By a landslide about 18,000 years ago broke a few thousand different large rocks of the Rocky Mountains from the area of present-day Jasper National Park, and fell down upon the surface of the underlying glacier. In this huge glacier it was the Cordillera Ice Sheet, which covered large parts of North America. The glacier transported the pieces of rock on his back hundreds of miles along the Rocky Mountains to the southeast. After the melting of the ice sheet of the Big Rock finally remained at its current location in a flat prairie are as erratic. The nearby town of Okotoks is named after him. In the language of the indigenous people native to this region, the Blackfeet, Okotoks ( o'kotok ) means Big Rock. He served as a milestone for the crossing point through the nearby Sheep River. In the 1970s, the Okotoks Erratic official historic site of the province of Alberta was. The rock was long on private land, to the province of the land on which it lies, eventually bought out in 1987.
The weight of the Big Rock is estimated at about 15000-16000 tons. It measures a length of 41 meters, a width of 18 meters and is nine feet high. Over time, he collapsed due to erosion associated with frost in two large and several smaller parts.
Big Rock is considered as a destination and as a tourist attraction. Contrary to the request of the competent authorities, it is often used despite the risk of further decay as rock climbing. In addition, historic Indian rock carvings are threatened in their existence by climbing.
Saga
To the stone block a legend entwines an encounter with Napi. Napi ( or even Napa Old -man) combines features of a deity ( creator of the world, with all its " errors " ), but also much that is human in itself; it occurs partly helping, but harming, as a fraud or mischief in appearance. So put Napi over high heat his coat on the Big Rock and promised the boulder before he wandered on, that he could keep it. Shortly thereafter it began to rain and Napi returned to his coat rent. As the rock refused Napi was annoying, just took his coat and went. Then he heard a loud rumbling behind him and saw that the rocks pursued him. He ran away and his friends, bison, deer and pronghorn were crushed as she tried to help him. Since Napi asked some bats for help. They attacked the rolling rocks and one hit him in the middle and split it into two parts.
Others
The Big Rock Brewery in Calgary used since its inception in 1985, the Big Rock as a brand name and popular figure.
Also large boulders are the Swedish Botsmarks flyttblock with an estimated 25,000 tons, a length of 35 meters and a height of 15 meters. In Germany similar, but smaller boulders are known, including the Buskams with an estimated 540 or 1600 tons and Dengel stone with about 1250 tons.