page_title: Amissville, Virginia
section_title: Geology
hierarchical_section_title: Amissville, Virginia / Geology
caption_attribution_description: Geological map of Rappahannock County, Virginia
context_page_description: Amissville is an unincorporated community in Rappahannock County in the U.S. state of Virginia. It is located on U.S. Route 211 about halfway between Warrenton and the small town of Washington, Virginia.
  The Locust Grove/R.E. Luttrell Farmstead and Meadow Grove Farm are listed on the National Register of Historic Places.
context_section_description: The geology of Amissville and the surrounding vicinity consists of several units. Predominant and oldest (approximately 704 million years old, +/- 5 million years, based on the U-Pb zircon geochronology dating method, coinciding with the initial rifting of the supercontinent Rodinia) is the Neoproterozoic alkali feldspar granitic rock of the Robertson River Igneous Suite. This includes felsic complex material such as biotite, hornblende-biotite, magnetite, and alkali granitic rock including rhyolite on the eastern slopes of Battle Mountain and Little Battle Mountain.
  Battle Mountain and Little Battle Mountain are the only mountains in Rappahannock County which are known to be volcanic in origin, and are among the oldest visibly intact extinct volcanoes in Virginia. White quartz boulders and smaller fragments are common on and around Battle Mountain, a result of molten silica that was contained in the rhyolite lava and granitic magma that formed the volcano.
  The Robertson River Igneous Suite extends from south of Laurel Mills (originating near Charlottesville) and runs north-northeast through Hackleys Crossroad and beyond in a band approximately four kilometers wide. Precambrian coarse leucogneiss and fine-grained gneiss prevails from the eastern edge of the Amissville, Rappahannock County area from north of the Amissville post office and U.S. Route 211 and south to Viewtown. Flint Hill Gneiss, a light to dark-gray quartz monzonite gneiss is predominate from Ben Venue and west to Massies Corner and extending further into Rock Mills and the town of Washington, Virginia.
  A fine-grained Precambrian arkosic sandstone and conglomerate, which Aaron Mountain is composed of, occurs on the contact between the Flint Hill Gneiss starting approximately two kilometers west of Laurel Mills and running north-northeast along a narrow band (starting out at approximately 1 kilometer wide and tapering down to 100 meters) in contact with the Robertson River Igneous Suite, terminating just south of U.S. Route 211. The creeksides and river bottoms of the Thorton River, Battle Run and the Rappahannock River and their smaller tributaries are all composed of Quaternary Period alluvium including stratified, unconsolidated gray to grayish-yellow sand, silt and local gravels.
caption: Geological map of Rappahannock County, with the village of Amissville shown on the far right
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