Peach Tree Rock Southern Lexington County, South Carolina
Field Report By Molly Malloy
Wednesday, January 24, 2001, a small group of soon to be geologists left the parking lot across from the PSC and started out on a journey into South Carolina's past. What they found was the Peach Tree Rock Preserve, an outstanding display of abstract sandstone formations.
The group started out by following a path down a hill into the main part of the preserve. The path on the way down had many interesting features in itself. One thing that was quick to notice were the clays that were exposed from cuts made into the land to make the path. These clays are present around the sides of the valley that contains Peach Tree and mark the top of the middle Eocene sequence that is present here.
The main attraction of Peach Tree Rock Preserve is an unusual sandstone formation that resembles a peach tree. The formation dates from the middle Eocene. The sands are very well sorted here, as well as throughout most of the preserve. Upon close examination of the formation one can see the many layers that compose the formation. At the base the bands seemed to be closer together and many holes and burrows were present in the formation. While many of these burrows may not be from when from the sediment was newly deposited (and may in fact be from present day wasps) some do in fact appear to be from roots or in other cases perhaps worms. The picture of the above was of one such feature seen at Peach Tree and is that of a shrimp borrow or Orphiomorpha. Also featured at Peach Tree were many beautiful cross beds.
One of the many things that the group discussed along the way was what kind environment exactly was responsible for the formation of the preserve. It was mentioned that the preserve could have been formed as a channel moved through the area. Another theory that the group mentioned was that it might have been formed from a barrier island and slowly the area moved closer to the shore and may have eventually become a beach before it became the area near Columbia that the locals treasure so much. The group pondered these possibilities as it moved on to its next destination. West of the main formation is a small waterfall that flows down into the valley. Here an impenetrable of silicified clays is exposed. This is the layer located directly above the sandstone that was seen in the main formation and also is present here. Following the path of the stream from the water there were some rocks present that showed the signs of being oxidized. They had distinctive red deposits on them and were slowly breaking apart.
Upon viewing the outcrops in the area we found that some contained fossils, such as the bivalve imprint shown in the picture to the right. However the group did not find a great variety of fossils and decided that they should move on to great and better outcrops. After a short hike and alot of arguing about which direction to go, the group finally found its way to a pair of outcrops standing close to each other and resembling two smoke stacks. The two formations contained a few more fossils, along with the base of what appeared to have once been a few stalagmites. However, one of the most impressive features that the group found at the double formation was herring bone cross bedding. This kind
ofcross bedding is characterized by the crossing of beds in two different directions and forming a pattern that resembles a herring bone. With this the group closed by discussing the importance of studying the local geology of South Carolina. They discussed how the South Carolina coast was at one time located in Columbia's back yard and that by studying the local geology one can better understand the world around them. As the group left the exact origins of the formations of Peach Tree Rock were still questionable.
However, it would not be hard to believe that the many sandstone layers were created at a time when this area was actually a beach on North America's coast. In final notes there is only one thing to definitely conclude. Peach Tree Rock and other local formations should be treasured for the mysteries and history that they unlock.