Dakota / Burro Canyon quartzite

Also called Dakota/Burro Canyon silicified sandstone, Dakota quartzite, Burro Canyon quartzite, KDB (Crow Canyon code)

Dakota / Burro Canyon quartziteQuartziteTexas & Southwest

Description

Dakota / Burro Canyon quartzite is the silicified sandstone of the Cretaceous Dakota Sandstone and Burro Canyon Formation, common around the Mesa Verde region of southwestern Colorado. Crow Canyon Archaeological Center says the two formations cannot be told apart by eye, so it treats them as one material. The stone is tan, white or light grey, sometimes medium grey, with a sugary glitter from microcrystalline quartz that replaced many of the sand grains. It is always hard and tough, with slightly rough, uneven surfaces, and may be opaque or slightly translucent. Ancestral Pueblo people used it for cores, pecking stones, bifaces, projectile points and drills, and also for manos. Burro Canyon chert, a finer stone from the same formation, is a separate material.

How to identify it

Colour: Tan, white or light grey, sometimes blending to medium grey (Crow Canyon).
Texture: Medium grained (grains visible with a hand lens); many sand grains dissolved and replaced by microcrystalline quartz. Always hard and tough. Opaque or slightly translucent (Crow Canyon).
Luster: Glistening, sugary sparkle on slightly rough, uneven surfaces (Crow Canyon).

Geology

Silicified sandstone of the Cretaceous Dakota Sandstone and Burro Canyon Formation. The sand was laid down by rivers, first cemented by silica, then many grains were replaced by microcrystalline quartz (Crow Canyon).

Where it comes from

Texas & Southwest, Rockies & Great Basin

States

Colorado

Quarries and outcrops

Local Dakota Sandstone and Burro Canyon Formation exposures, Mesa Verde region, southwestern Colorado (Crow Canyon)

Used by

Ancestral Pueblo, Mesa Verde region: debitage, cores, pecking stones, bifaces, projectile points, drills and manos (Crow Canyon)

Look-alikes

Stones that are easy to confuse with Dakota / Burro Canyon quartzite.

Burro Canyon chert: much finer, shiny, with chalcedony blebs (Crow Canyon)
Morrison silicified sandstone: maroon, green, tan and brown, dull and rough (Crow Canyon)

Sources

Ortman, Scott G., Erin L. Baxter, Carole L. Graham, G. Robin Lyle, Lew W. Matis, Jamie A. Merewether, R. David Satterwhite, and Jonathan D. Till. 2005. The Crow Canyon Archaeological Center Laboratory Manual, Version 1. Chapter 8, Stone Material Identification. Crow Canyon Archaeological Center, Cortez, Colorado.crowcanyon.org (opens in a new tab)

All materials