Antietam Formation
Geologic formation in the United States
From Wikipedia, the free encyclopedia
The Antietam Formation or Antietam Sandstone is a geologic formation in Pennsylvania, Maryland, West Virginia, Virginia, and Tennessee.[3][4][5][1]. In Virginia and Tennessee, it is known as the Erwin Formation.[1] It is largely quartz sandstone with some quartzite and quartz schist. It preserves Skolithos trace fossils dating back to the Cambrian Period.[6] A nevadiid specimen from Tennessee is the earliest known definitive trilobite in the southern Appalachians.[1]
Tight folds in the schist of Antietam Formation
Thin section of schist. Porphyroblastic biotite, a, in a dolomitic matrix. The tourmaline, t, is epigenetic.
| Antietam Formation | |
|---|---|
| Stratigraphic range: Cambrian Stage 3[1] | |
 Anticline in schist of Antietam Formation | |
| Type | Formation |
| Unit of | Chilhowee Group |
| Underlies | Tomstown Dolomite |
| Overlies | Harpers Formation |
| Thickness | 550 ft |
| Lithology | |
| Primary | Sandstone, quartzite |
| Other | Schist |
| Location | |
| Region | Appalachia, Eastern United States, and Southeastern United States |
| Country | United States |
| Extent | Maryland, Pennsylvania, West Virginia, Virginia,[2] and Tennessee |
| Type section | |
| Named for | Antietam Creek |
