The geology of Turkey Run may be said to have begun when the great masses of sandstone, from which the gorge is carved, were deposited upon the vast inland sea which covered this area during the time when coal was being formed. After the deposition of this sandstone, which geologists call the Mansfield, this great sea became shallow, being replaced by marshes of no great depth. In these marshes, under tropical conditions, a rank vegetation sprang up. Here flourished the lordly evergreens of Carbonic time—the Lepidodendron (sometimes called the "Scale Tree") and the Sigillaria, whose trunk bears a delicate seal-like impression upon its surface. More than a hundred varieties of the former have been described, some of whose trunks have measured a hundred feet. The latter, the largest of carboniferous trees, bore trunks reaching six feet in diameter and more than a hundred feet in height. Here, too, grew the Calamites, or giant rushes, and tree ferns of bewildering variation. This accumulated vegetation was at length buried under subsequent deposits and later transformed into coal under the great pressure which resulted. Following this came marine conditions similar to that which exists under our present seas until several hundred feet of sediment had been deposited above the massive layer of Mansfield sandstone. Later this sea receded permanently and land conditions prevailed. Then followed a long period of weathering and erosion, during which time prodigious layers containing coal, hundreds of feet in thickness and overlying the sandstone, were removed. The reader will realize that we are talking, not in hundreds and thousands of years but in geologic ages when we speak of these various phases.
The exposed bedrock here is Mans field sandstone. This deposit was formed during the Carboniferous Period, when the buildup of sand at the mouth of the ancient Michigan River was slowly compacted and cemented into solid rock. The swampy environment of this period produced vast coal deposits. The Mansfield sandstone, which was named from exposures in the quarry at Mansfield in Parke County, is massive, coarse-grained, cross -bedded, and variegated. This sandstone fills the valleys which were eroded at the end of Mississippian time. Contrary to popular opinion, however, the Mansfield formation is not in all places a massive sandstone. In Parke County, it contains a few thin lenticular coals and, locally, as much as 20 to 30 feet of shale. In other areas, the formation is almost entirely shale or may contain shale, several coals, and at least two thin limestones. Coal was mined here in the late 1800s and early 1900s. Seams of coal are still visible along many of the trails
The Coal Mine, near the intersection of trail 4 and trail 8, was used by John Lusk for many years as the source of his coal supply. The shaft and the old track used in drawing the coal out is still to be seen. This mine was in operation from the late 1800's through the 1920's. The coal was hauled out by donkey to heat the Lusk Home on property and other buildings within the park. The mine was too small to be of commercial value but was very valuable to the park and to the only private owners of the park land; Salmon and John Lusk.
Send the following answers to my account to receive credit for this earthcache. Some answers will be on the signs nearby.
1. What 2 things are needed to turn peat into coal?
2. How tall is the mine? Can you see any coal inside the mine?
3. Who are the current occupants of the coal mine?
4. Where was Indiana located during the Pennsylvanian Period?
5. What type of mine is this?
6. Post a picture of yourself (face not required) or a personal item at the mine. Please don't include pictures of the signs with the answers. Thanks.