Mauch Chunk Formation facts for kids
Quick facts for kids Mauch Chunk FormationStratigraphic range: Mississippian |
|
|---|---|
| Type | Formation |
| Underlies | Pottsville Formation |
| Overlies | Pocono Formation |
| Location | |
| Region | Maryland, Pennsylvania, West Virginia, |
| Country | United States |
The Mauch Chunk Formation is a special type of rock layer. It's found in parts of Pennsylvania, Maryland, and West Virginia. This rock formation is mostly from the Mississippian time period. It's named after a place called Mauch Chunk, which is now known as Jim Thorpe, Pennsylvania. You can see these rocks sticking out of the ground near Mauch Chunk Ridge.
Contents
What is the Mauch Chunk Formation Made Of?
The Mauch Chunk Formation is made up of different kinds of rocks. These include grayish-red shale (a soft, layered rock), siltstone (like fine sandstone), sandstone (made of sand grains), and conglomerate (a rock with rounded pebbles).
Special Rock Layers Inside
Sometimes, you'll find special layers within the Mauch Chunk Formation. One of these is called the Loyalhanna Member. It's a type of limestone or sandy limestone. Other special layers are the Greenbrier and Wymps Gap Members. Near a place called the Allegheny Front, the Loyalhanna layer is a greenish-gray sandstone with crisscross patterns.
How These Rocks Were Formed
The rocks in the Mauch Chunk Formation tell a story about ancient Earth.
- Early Layers: The first layers were laid down in a huge basin. This basin got its sand and mud from faraway mountains.
- Changing Sea Levels: Sometimes, the sea level changed. This allowed limestone to form in some areas.
- Red and Green Rocks: Most of the Mauch Chunk rocks are red. This means they formed in places that were dry and open to the air. The green rocks, however, formed in wet places. These could have been swamps, river deltas, or shallow seas.
- Mountain Building: Later layers of the Mauch Chunk Formation have lots of conglomerate rocks. These rocks signal the start of a huge mountain-building event. This event is known as the Alleghenian orogeny.
Ancient Life in the Rocks
Scientists have found some cool fossils in the Mauch Chunk Formation.
- Plants: They've found fossils of ancient plants called Pteridospermatophyta. One type found is called Adiantites.
- Animals: There are also signs of ancient fish and worm burrows.
How Old is the Mauch Chunk Formation?
The Mauch Chunk Formation is very old! Most of it formed during the late Mississippian time period. Some of the very top layers might even be from the early Pennsylvanian time. These rocks were laid down between 345 and 320 million years ago.
The Mauch Chunk Formation usually sits directly on top of other rock layers. Above the Mauch Chunk, you will always find the Pottsville Formation.
What Are These Rocks Used For?
In 1953, people found a small amount of uranium in the Mauch Chunk Formation. This was near Jim Thorpe, Pennsylvania. Uranium is a special metal that can be used for energy. You can learn more about this at Uranium mining in the United States.
