Rich Acres Norite named for community of Rich Acres, Martinsville West quad, Henry Co., south-central VA. Exposed in several distinct plutons in quad, including type locality at Rich Acres in southeastern part, at and north of Villa Heights in northeastern part, at Collinsville in north-central part, east of Stanleytown in northern part, and in small pluton on tributary of Shelton Branch in southwestern part. Consists of intermediate to dark-greenish gray, porphyritic, nonfoliated, coarse-grained norite. Intrudes sillimanite-mica schist, biotite gneiss, granite gneiss, and Leatherwood Granite. Contact with older rocks is almost a hairline. Age is late Paleozoic. It intrudes late Paleozoic Leatherwood Granite so it is considered slightly younger; zircon correlations indicate that Leatherwood and Rich Acres formed from same parent magma. Report includes geologic map and cross sections.
Source: GNU records (USGS DDS-6; Reston GNULEX).
Significant amounts of gabbro and diorite were found in Rich Acres Norite in this area. Therefore, name is changed to Rich Acres formation.
Source: GNU records (USGS DDS-6; Reston GNULEX).
Martinsville igneous complex includes unnamed norite, Leatherwood Granite, and Rich Acres Formation (base). Age is Ordovician.
Source: GNU records (USGS DDS-6; Reston GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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