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Geologic Unit: Leader Lake
Map showing publication footprint
  • Usage in publication:
    • Leader Lake Quartz Monzonite
  • Modifications:
    • Named
    • Geochronologic dating
  • AAPG geologic province:
    • Okanogan province
Publication:

Menzer, F.J., Jr., 1983, Metamorphism and plutonism in the central part of the Okanogan range, Washington: Geological Society of America Bulletin, v. 94, no. 4, p. 471-498.


Summary:

Unit is named the Leader Lake Quartz Monzonite. Is a post-metamorphic, orthomagmatic stock in the central Okanogan Range, WA. Consists of fine- to medium-grained rocks composed of equal amounts of quartz, zoned oligoclase, and microcline and minor amounts of biotite and muscovite. Intrudes the Conconully Granodiorite (new), but a radiometric age (Rb-Sr mineral isochron) of 81 Ma is considered to be evidence that it is a slightly younger differentiate of the same parental magma as the Conconully Granodiorite. Age is Late Cretaceous. (B1565)

Source: GNU records (USGS DDS-6; Menlo 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 ([ ]).

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