I WILL DELETE ANY SPOILERS(LOGS/PICTURES) THAT INDICATE THE ANSWER TO THE QUESTION.
Within the city limits of Ely, Minnesota lies a hidden treasure, unknown by tourists.
PILLOW ROCK, is an example of some of the oldest rock in the world. It is about 15 ft. wide by 8 ft. high. ( Area may be undergoing restoration)
The astronauts were brought here in 1970 to study the greenstone because it was so similar to rock that was expected to be found on the moon.
It was formed 2.7 billion years ago, from underwater volcanic activity in which basaltic lava flows poured out of the earth’s crust and into the cold sea, which then covered much of what is now NE Minnesota. Geologists think this occurred along plate boundaries much like the activities along the Mid-Atlantic Ridge today. The rapid cooling of the lava as it hit the cold seawater, caused an unusual parting of the lava to create “pillow” (ellipsoidal) formations. During later geological periods, these lava flows were highly altered. High concentrations of chlorite and actinolite were absorbed into the lava flows giving the formation a grey-green color, from which it gets its name ELY GREENSTONE.
What makes this exposure interesting is that the pillows are seen in their original 3-dimensional shapes. It originally was located about 300 feet north of this site, but was moved here by a glacier.
Greenstone belts occur around the world and are often associated with economic mineral deposits. The Ely Greenstone contains an isolated body of iron ore about 1.75 miles long and nearly 1 mile wide. To view the remains of the open pit and head frame of an underground shaft go to: http://www.geocaching.com/seek/cache_details.aspx?guid=a44be443-44da-48a6-942a-fd59f7703056
TO GET CREDIT FOR THIS CACHE EMAIL ME THE CORRECT ANSWER TO THIS QUESTION: USING YOUR GPS COMPASS, WHICH SIDE OF THE MAIN OUTCROP HAS EROSION EXPOSED THE LARGEST PILE OF PILLOWS?(I WILL NOT ACCEPT RIGHT,LEFT, FRONT OR BACK - I AM LOOKING FOR A COMPASS DIRECTION). FAILURE TO EMAIL ME THE ANSWER AT THE TIME YOU LOG THE CACHE WILL RESULT IN YOUR LOG BEING DELETED.