| Lock Haven Formation | |
|---|---|
| Stratigraphic range: Devonian | |
| Brachiopod casts in the Lock Haven, Leberfinger Quarry, Sullivan County, PA | |
| Type | sedimentary |
| Unit of | Susquehanna Group |
| Sub-units | lower shaly member, upper sandy member, Minnehaha Springs Member |
| Underlies | Catskill Formation |
| Overlies | Brallier Formation |
| Lithology | |
| Primary | siltstone, shale, sandstone |
| Other | conglomerate |
| Location | |
| Region | Appalachian Mountains |
| Country | United States |
| Extent | Pennsylvania |
| Type section | |
| Named for | Lock Haven, Pennsylvania |
| Named by | Faill and Wells, 1977 [1] |
The Lock Haven Formation is a Devonian mapped bedrock unit in Pennsylvania, in the Appalachian Mountains of the United States.
The Lock Haven is gray to green-brown sandstone, siltstone, and shale and is over 400 million years old. It is located in northcentral Pennsylvania. [2] [3]
The Lock Haven may underlie various members of the Catskill Formation, although it may be a lateral equivalent of the Sherman Creek or Irish Valley Members of the Catskill. It is also a lateral equivalent of the Foreknobs Formation and underlying Scherr Formation. The Brallier Formation usually underlies the Lock Haven. [4]
The Minnehaha Springs Member (originally proposed as a member of the Scherr Formation) is a "clastic bundle" consisting of interbedded medium gray siltstone and olive gray shale with some grayish-red siltstone and shale and some sandstone. It is interpreted as turbidites. [5] This member is proposed to define the base of the Lock Haven Formation. [6]