- Usage in publication:
-
- Spikehorn Creek Granite*
- Modifications:
-
- First used
- Geochronologic dating
- Overview
- AAPG geologic province:
-
- Lake Superior region
Summary:
First use in fig 3, but referred to in text informally as granite of Spikehorn Creek. Isotopic U-Pb zircon age of 1,835 +/-6 Ma recorded. Summary of geology, geochronology, and geochemistry of Early Proterozoic rocks within and adjacent to the Dunbar dome in northeastern Wisconsin.
Source: GNU records (USGS DDS-6; Denver GNULEX).
- Usage in publication:
-
- Spikehorn Creek Granite*
- Modifications:
-
- Named
- Dominant lithology:
-
- Granite
- AAPG geologic province:
-
- Lake Superior region
- Wisconsin arch
Summary:
Named as one of three granitoid bodies which compose three respective lobes of the Dunbar dome. The Niagara lobe is composed of the Spikehorn Creek Granite. Name derived from Spikehorn Creek, which flows through the area where the lithodeme is exposed. Type area in sections 35 and 36, T38N, R20E, Pembine 15 minute quadrangle, Marinette Co, WI. Consists of gray to pinkish-gray, fine- to medium-grained, massive granite containing scattered anhedral phenocrysts of K-feldspar as long as 1.5 cm; mortar structure is common. Intrudes Marinette Quartz Diorite and Quinnesec Formation; seems to grade westward into Hoskin Lake Granite. Assigned to the Early Proterozoic. Age, 1,836 +/-15 Ma (Sims and others, 1984).
Source: GNU records (USGS DDS-6; Denver 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 ([ ]).