Pg. 196-197. Somerville slate. Is litholgically similar to recognized Cambrian slates of the [Boston] region and markedly disimilar to known Carboniferous rocks of neighboring areas, especially to those of Narragansett Basin.
Occurs at and around Somerville, Middlesex Co., eastern MA.
Source: US geologic names lexicon (USGS Bull. 896, p. 2026).
Pg. 316. Somerville slates, 2,300 feet thick, grade into underlying Sqantum tillite of Roxbury conglomerate through transition beds of shales or slates, sandstones, and conglomerates 200 to 300 feet thick. [Age is Carboniferous or Devonian.]
Source: US geologic names lexicon (USGS Bull. 896, p. 2026).
†Somerville slate. Mapped the rocks at and around Somerville, Massachusetts, as Cambridge slate and the name "Somerville slate" has been discarded.
Source: US geologic names lexicon (USGS Bull. 896, p. 2026).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
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