Friday, September 24, 2010

Ancient River Valley

The ancient sediment-filled river valley home to the Pleasant Valley Conservancy State Natural Area near Black Earth, Wisconsin.

Thursday, September 23, 2010

Wisconsin Homestead

Wisconsin Homestead, originally uploaded by jw_creations.

Friday, September 3, 2010

Boundary Waters Canoe Area Wilderness

The Boundary Waters Canoe Area Wilderness, is a 1.09 million acre (4,410 km²) wilderness area within the Superior National Forest in northeastern Minnesota.

The lakes of the BWCAW are located in depressions formed by differential erosion of the tilted layers of the Canadian Shield. For the past two million years, massive sheets of ice have repeatedly scoured the landscape; the last glacial period ended with the retreat of the Laurentide Ice Sheet from the Boundary Waters about 17,000 years ago.The resulting depressions in the landscape later filled with water, becoming the lakes of today.

Many varieties of Precambrian bedrock are exposed, including granite, basalt, greenstone, gneiss, as well as metamorphic rocks derived from volcanic and sedimentary rocks. Greenstone of the Superior craton located near Ely, Minnesota is up to 2.7 billion years old, some of the oldest exposed rock in the United States. Igneous rocks of the Duluth Complex comprise the bedrock of the eastern Boundary Waters. Ancient microfossils have been found in the banded iron formations of the Gunflint Chert.

Check this link for more info: