Norbeck Intrusive Suite

The Norbeck Intrusive Suite is an Ordovician granitic pluton in Montgomery County, Maryland. The intrusive suite was originally mapped as the Norbeck Quartz Diorite by Hopson,[1] and is shown as such on the Geologic Map of Maryland of 1968.[2] A. A. Drake later revised the name after more detailed mapping.[3] It intrudes through the Wissahickon Formation.

Norbeck Intrusive Suite
Stratigraphic range: Ordovician
Outcrop of tonalite at Greenwood Local Park, Brookeville
Typeigneous
Lithology
Primarytonalite, metadiorite, metagabbro
Location
RegionPiedmont of Maryland
ExtentMontgomery County
Type section
Named forNorbeck, Maryland
Named byC. A. Hopson, 1964[1]

Description

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Three lithologies were mapped in the Kensington quadrangle by Drake:[3]

References

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  1. ^ a b Hopson, C.A., 1964, The crystalline rocks of Howard and Montgomery Counties: Maryland Geological Survey County Report, 337 p., (Reprinted from Cloos, Ernst, and others, "Geology of Howard and Montgomery Counties," p. 27-215)
  2. ^ Geologic Map of Maryland, 1968. Maryland Geological Survey.
  3. ^ a b Drake, A.A., Jr., 1998, Geologic map of the Kensington quadrangle, Montgomery County, Maryland: U.S. Geological Survey Geologic Quadrangle Map, GQ-1774, scale 1:24,000