- Usage in publication:
-
- Hope Member
- Modifications:
-
- Named
- Dominant lithology:
-
- Dolomite
- Chert
- AAPG geologic province:
-
- Appalachian basin
Summary:
Hope Member of Rickenbach Formation named in Warren Co., north-central NJ. Described as gray to dark-gray aphanitic to coarsely crystalline, medium- to massive-bedded dolomite with chert beds. Characterized by internal brecciation. Overlies lower, unnamed member of Rickenbach Formation and underlies Branchville Member of Epler Formation. Intertongues with informal Crooked Swamp dolomite facies of Rickenbach, which is well developed north of Lafayette, Sussex Co., NJ. Age is Early Ordovician.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Hope Member
- Modifications:
-
- Overview
- AAPG geologic province:
-
- Appalachian basin
Summary:
Nomenclature followed here is that of Markewicz and Dalton (1977) who divided the Rickenbach Formation into a lower unnamed member, the overlying Hope Member, and a distinct facies named the Crooked Swamp dolomite. The Hope Member is as much as 175 ft thick and consists of light- to medium-gray, gray weathering, aphanitic to finely crystalline, medium-bedded dolomite interbedded with darker gray, dark-gray weathering, more coarsely crystalline, medium- to massive-bedded dolomite. It contains several distinctive chert beds. The Hope underlies the Epler Formation. Age of the Rickenbach is Early Ordovician.
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 ([ ]).