This is an Earthcache and to claim a find, message me the answers of YOUR CHOICE of each question below (there are 2 questions for you to answer)..per updating with new EC's recommendations...AND add a picture of yourself or group at Gypsy Gultch post/sign to your log ... Thank you & enjoy your visit here...
**** Read the info, look at the pictures below of each type, to answer the questions..
- Describe the colors of the cross-bedding OR Approximate length of this feature..
- Identify the type of cross-bedding, and state your reasoning Or Identify if is a sub-type & what & why you chose this..
Welcome to Turkey State Park… The park was listed on the National Register of Historic Places in 2019… Nice trails and the rugged beauty will astound you… as you hike through many rock levels and formations..
Turkey Run State Park is made up primarily of Mansfield sandstone, the rocks of the canyon walls date back some 300 to 600 million years… The steep bedrock cliffs & small streams in Turkey Run State Park tell of two chapters in its long geologic history… The first chapter starts about 225 million years ago, during the Pennsylvanian Period… The second chapter tells of the last million years, the ice Age or Plestocene Epoch…which lasted until glacial meltwaters from the north around 12,000 years ago…
The Pennsylvanian Strata - the cliffs of Gypsy Gulch consist mainly of coarse-textured sandstone, which was originally a body of sand deposited when rivers flowed through this area… This section of Indiana was a river delta that emptied into a shallow sea…. The flowing sediment and variations in the rivers coarse, water volume, and sediment load created layers at angles while underwater… evidenced by striations in the rocks, called cross-bedding… Compaction and cementation through geologic time have changed the original sediment into sedimentary rock…
Crossbedding is common throughout the park and in sandstone in general… The surface weather of the bedrock really brings out the details in the rock layers and formations…
In the last few hundred years, the wind and water erosion of the sandstone has continued at a slower pace. The gorges you see here are very similar to what was seen by Native Americans and pioneers.
Cross-bedding can tell geologists what an area was like in ancient times...The direction the beds are dipping indicateds paleocurrent, the rough direction of sediment transport...Cross-bedding can form in any environment in which a fluid flows over a bed with mobile material... Sedimentary rocks are normally deposited as horizonal layers… Even when folded or tilted by faulting the originally horizontal layering is obvious.. This is called tabular cross-bedding or simple cross-bedding..…
But when you see a curved angle to the main bedding, where tilted layers are contained within larger layers, this is called trough cross-bedding…
Trough cross-bedding can be further differentiated in sub-types:
Festoon cross-bedding is made with more rounded ripples and dunes cutting back and forth into each other and creating swooping cross-beds…
Convoluted cross-bedding is made when the layers were originally roughly horizontal, deposited on a gentle bowl-shaped bottom… then the sediment on the edges of the bowl slumped toward the center and these beds were forced into complex folds... can see one or many convoluted features...
Herringbone cross-bedding is made of matched sets of cross-beds tilting in opposite directions… these are commonly produced by tidals moving in and out of a shallow sea... Looks like a herringbone or zigzag pattern...
**** SEE PICTURES BELOW OF DIFFERENT TYPES OF CROSS-BEDDING..
References:
Wikipedia Cross-beding ... www.turkeyrunstatepark.com ... Univerisity of Pittsburgh, Department of Geology and Planetary Science, Cross-bedding ... Bridges, K. H. P. 1977, Geologic story of Turkey Run State Park: Indiana Geological Survey State Park Guide 05 ... Wikipedia Turkey Run State Park
Thank-you to Aaron Douglass, Interpretative Naturalist, Turkey Run State Park for his assistance & approval for this Earthcache...
FTF Congratulations !!!
To lady_xythis for logging and completing EC requirements first.. and getting her EC souvenir!!!
To Bragger407 & LaFavorite Cacher for visiting first…