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National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • West Rock Diabase*
  • Modifications:
    • Named
  • Dominant lithology:
    • Diabase
  • AAPG geologic province:
    • Hartford basin
    • New England province
Publication:

Fritts, C.E., 1962, Age and sequence of metasedimentary and metavolcanic formations northwest of New Haven, Connecticut; Article 128, IN Geological Survey Research 1962; short papers in geology, hydrology, and topography; Articles 120-179: U.S. Geological Survey Professional Paper, 450-D, p. D32-D36.


Summary:

The West Rock Diabase, here named, intruded the New Haven Arkose at about the same time that the Talcott Basalt of the Newark Group was extruded above the arkose. It was later intruded by the Buttress Diabase. Age is Late Triassic.

Source: GNU records (USGS DDS-6; Reston GNULEX).


Map showing publication footprint
  • Usage in publication:
    • West Rock Dolerite
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Hartford basin
    • New England province
Publication:

Rodgers, John, 1985, Bedrock geological map of Connecticut: Connecticut Geological and Natural History Survey, scale 1:125,000


Summary:

The West Rock is redefined as West Rock Dolerite. It is dark-gray to greenish-gray, medium- to fine-grained, grading from basalt near contacts to fine-grained gabbro in the interior, generally massive, with columnar jointing. Age is Early Jurassic.

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 ([ ]).