Lock Haven Formation | |
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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]