The National Geologic Map Database is migrating to a new infrastructure. We apologize for any service disruptions during this process.
|
|---|
- Usage in publication:
-
- Lake Katrine Member
- Modifications:
-
- Named
- Dominant lithology:
-
- Claystone
- Mudstone
- Shale
- AAPG geologic province:
-
- Appalachian basin
Summary:
The Port Ewen Formation of the Helderberg Group is subdivided into two members in the Silurian-Devonian outcrop belt in eastern New York. The lower member is here named the Lake Katrine Member. It consists of dark-gray to brown weathering, fissile to hackly, burrow mottled, nonresistant, platy claystone, mudstone, and shale with bioclastic debris and coarse-grained carbonate at the base. Transitionally overlies the Alson Formation; underlies the East Kingston Member of the Port Ewen. Thickness at type section is 6 m. Age is Early Devonian.
Source: GNU records (USGS DDS-6; Reston GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).