Usage:
Alsen Limestone of Helderberg Group (NY*)
Alsen Formation of Helderberg Group (NJ,NY)
Geologic age:
Early Devonian*
Type section, locality, area and/or origin of name:
Named from section at Alsen, Greene Co., east-central NY, where it is well shown in the hills (Grabau, 1919).
AAPG geologic province:
Appalachian basin*
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 ([ ]).