The 366 daily episodes in 2014 were chronological snapshots of earth history, beginning with the Precambrian in January and on to the Cenozoic in December. You can find them all in the index in the right sidebar. In 2015, the daily episodes for each month were assembled into monthly packages, and a few new episodes were posted. Now, the blog/podcast is on a weekly schedule with diverse topics, and the Facebook Page showcases photos on Mineral Monday and Fossil Friday. Thanks for your interest!

Monday, June 23, 2014

June 23. Appalachian in Iowa

The effects of continent-continent collisions can be felt far into the continents that are involved. Today’s collision between India and Eurasia, which has been going on for 30 or 40 million years, has helped to produce extension 2500 miles, 3700 kilometers away from the collision, at Lake Baikal in Siberia. 

The Appalachian-Ouachita Orogeny had impacts as far away as Iowa quite early in the collision. Early Mississippian marine carbonate rocks were tilted and folded and uplifted and eroded before Pennsylvanian coal-bearing strata were deposited. There’s a pretty good unconformity between those sets of rocks.
—Richard I. Gibson

Reference: Coal Deposits of Iowa, by C.R. Keyes, Iowa Geological Survey, 1894.

No comments:

Post a Comment