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Newman Limestone and Boyle cherts, photo 1
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Named stone

Newman Limestone and Boyle cherts

Also called Haney chert, Paoli chert, Carter Cave flint, Ste. Genevieve chert (Kentucky), St. Louis chert (Kentucky green), Boyle chert

A kind of chert (and flint)

Newman Limestone and Boyle chertsChert (and flint)Midwest/Ohio Valley

Description

Kentucky's most-used local cherts come from two units. Boyle chert occurs in the Middle Devonian Boyle dolomite of central and eastern Kentucky as large blocky nodules with a chalky white rind, while stream cobbles wear a smooth polished brown skin. Its interior is mottled tan, blue, yellow, gray and brown, earthy to waxy, and often full of fossils. The Mississippian Newman Limestone carries four chert types named for its members: Haney (white to brown, oolitic, translucent), Paoli (nonfossiliferous and colorful in red, orange, yellow and tan, glassy, also called Carter Cave flint), Ste. Genevieve (dark gray to grayish black) and green St. Louis chert. At the Howard site in Madison County these cherts supplied about two-thirds of the stone.

How to identify it

Colour
Boyle: tan, blue, yellow, gray and brown mottled. Haney: white and buff to tan, brown and dark brown, sometimes banded. Paoli: red, brown, orange, yellow and tan lines and swirls. Ste. Genevieve: very dark gray to dark greenish gray to grayish black. St. Louis: white to red to green, mostly green.
Texture
Boyle: earthy to waxy. Paoli: highly silicified and nonfossiliferous. St. Louis: dense; green nodules are almost spherical and need considerable force to break.
Luster
Paoli is vitreous and shiny; Ste. Genevieve is vitreous; Haney is translucent and fractures easily.
Inclusions
Boyle can be highly fossiliferous (bryozoans, brachiopods, corals, crinoids, echinoderms). Haney carries oolites visible to the naked eye.
Cortex
Boyle has a chalky white primary cortex, or a smooth polished brown cortex on stream cobbles.
Heat treatment
Only Boyle and Muldraugh cherts show intentional heat treatment at the Howard site (Pollack and Schlarb).

Geology

Boyle chert is in the Middle Devonian dolomites of the Boyle Formation of central and eastern Kentucky, as nodules and discontinuous layers, weathering out in clayey soil. The Mississippian Newman Limestone crops out along the western edge of the Eastern Coalfields and near the Pine Mountain overthrust, and holds several chert-bearing members (Haney, Paoli/Beaver Bend, Ste. Genevieve, St. Louis); each member has its own chert subtype. The Howard site report finds that most of the chert there was procured from nearby streams as cobbles.

Where it comes from

Midwest/Ohio Valley

States

Quarries and outcrops

  • Berea and Bighill quadrangles, Kentucky (Newman Limestone outcrops south of the Howard site)
  • Boyle Formation outcrops, central and eastern Kentucky
  • Pine Mountain overthrust, southeastern Kentucky (Newman Limestone)

Used by

  • Fort Ancient: Howard site, Madison County; fine triangular points, drills, scrapers and bifaces of Boyle, Haney, Paoli and Ste. Genevieve chert (Pollack and Schlarb)
  • Late Archaic contracting stemmed point of Haney chert (same site)

Look-alikes

Stones that are easy to confuse with Newman Limestone and Boyle cherts.

  • Other Kentucky cherts: Breathitt (Pennsylvanian; gray, olive), Muldraugh (light to dark gray)
  • Wyandotte chert (also Ste. Genevieve)
  • Harrodsburg chert

Sources

  1. Pollack, David, and Eric J. Schlarb. 2009. Archaeological Investigations of the Early and Late Fort Ancient Howard Site (15MA427), Madison County, Kentucky. Kentucky Archaeological Survey Report 151.kentuckyarchaeologicalsurvey.org (opens in a new tab)
  2. U.S. Geological Survey. The Geology of Kentucky: Mississippian System (Professional Paper 1151-H).pubs.usgs.gov (opens in a new tab)

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