Red Hill EarthCache
-
Difficulty:
-
-
Terrain:
-
Size:  (other)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
Approved until June 6th,2024.
We have earned GSA's highest level: |
|
Red Hill is a Late Devonian (Famennian Stage) fossil site located in central Pennsylvania. Its geology tells us that Red Hill was formed about 361 million years ago by a large lowland river with extensive floodplains. An impressive variety of animal and plant fossils have been recovered from this site, the most renowned of which are the earliest known tetrapods from North America. The fossils from Red Hill have come from two broad types of deposits. Most of the vertebrate fossils, including the tetrapods, have been recovered from the shallow channel margin deposits. Vertebrate fossils have also been recovered from the floodplain pond (or overbank pond) deposits. In addition, the pond deposits have yielded an abundance of plant fossils as well as some invertebrates.
Shallow Channel Margin
The shallow channel margin deposits are made up red sandy siltstone sediments, but lenses of sandier red sandstone are also present. Most of the vertebrate fossils consist of disarticulated (separated) bones that show little sign of transport or reworking. Associated skeletal elements have been found in several lenses, as have articulated specimens of smaller fishes. Most if not all of the vertebrates apparently came from the floodplain exysystem. At least 13 vertebrate taxa have been recovered from the shallow channel margin deposits. This makes Red Hill the most diverse vertebrate assemblage associated with Late Devonian tetrapods. Turrisaspis elektor was the most numerous species, but Phyllolepis, Ageleodus, Gyracanthus, and an assortment of lobe-fin fishes are frequently collected. These vertebrates ranged from the formidible Hyneria lindae, which may have exceeded 3 m in length, to the diminutive Turrisapsis and ray-fin fishes .
Examples of Vertebrates found here:
Placoderms (armored fishes),Chondrichthyans (sharks),Acanthodians (spiny-fin fishes),Actinopterygians (ray-fin fishes),Sarcopterygians (lobe-fin fishes) .
Floodplain Pond Facies
The floodplain pond deposit at Red Hill is made up of mudstone and very fine grained sandstone. The small grain size of these rocks indicate that they were laid down in sluggish waters. Their color was the result of reducing conditions caused by the decomposition of abundant plant debris. Thin layers of rock are found thoughout Red Hill, but a 1.5 m thick layer extends through much of the exposure. This layer is believed to be an floodplain pond. The quiet waters of the floodplain pond increase the chances that some of the plants and animals in or near it will become fossilized. In fact, many of the vertebrate fossils found here are articulated (their bones have not been scattered), whereas most fossils from the shallow river margin are disarticulated (scattered). The abundance of delicate plant fossils and the presence of fragile invertebrates are also the result of favorable conditions. A total of six vertebrate taxa have been collected from the floodplain pond. Articulated specimens of the ray-fin fish, Limnomis delaneyi and an undescribed rhizodont have been collected here, which suggest that these species were residents. The other vertebrates were represented by smaller bone fragments and individual scales, suggesting that these taxa may have been washed into the lake during flooding. A large progymnosperm tree, Archaeopteris, and an ancient fern, Rhacophyton, account for most of the identifiable plant fossils, but a relatively diverse assortment of other vascular plants was also found. These include two arborescent lycopsids, barinophytes, another ancient fern, and early seed plants.
Examples of Vertebrates found here:
Placoderms (armored fishes),Actinopterygians (ray-fin fishes),Sarcopterygians (lobe-fin fishes)
To log this Earthcache as a find please email us through geocaching.com within 48 hours if questions are not answered your log will be deleted without notification. PLEASE do not post the answers to the following questions.
1. The posted coordinates will take you to a spot along the bottom of Red Hill name 3 different colors of the layers of rocks in front of you?
2. What is the texture of Red Hill when you touch it the rocks?
3. Speculate what is the cause of the loose deposits of the rocks at the base of Red Hill besides from humans visiting?
4. Which part of Red Hill has the most evidence of erosion top,middle,or bottom?
Please do not post SPOILER pictures with your logs. That would give the answers away.
Please only visit Red Hill during daylight hours only. Also please do not climb up Red Hill if anyone does it will result in the Earthcache being archived Thank You and enjoy your visit to Red Hill
All information obtained from this website http://www.devoniantimes.org
Additional Hints
(No hints available.)