BURRO CREEK

WESTERN ARIZONA

Sections 4,8,9,10,15,16 R11W, T14N Kaiser Spring 7.5' Quad, southeast Mohave and west central Yavapai Counties, Arizona (see Moyer 1990). Burro Creek is the farthest northwest of all the sources in the study region. The actual source (a vitrophyre near Kaiser Spring) was investigated by Tom Moyer for master's and Ph.D. research in geology at Arizona State University (1982). Moyer was sensitive to the importance of the source for archaeology and his research at the locality was quite useful. Much of the information here derives from his work. A K-Ar date on the obsidian was 12.0 0.6 Ma (Moyer 1990).

The origin of the obsidian is within a vitrophyre similar to Los Vidrios as part of a series of rhyolite domes called the Burro Complex (Moyer 1984). The nodule density at the source is not available, but the downstream density in Burro Creek Wash (up to 5 per 5m2) suggests that the nodule density in and around the vitrophyres is equal to Los Vidrios or Superior. The largest nodule recovered was 7 cm in diameter, but like Vulture and Superior, Burro Creek is a known "Apache Tear" collection area, so the density and nodule sizes observed are probably skewed. The knapping quality is excellent, equal to Vulture, Superior and Sauceda.

The aphyric Burro specimens do not have a strongly developed cortex. Some have perlite coatings, but most exhibit weathered black glass cortical material. The aphyric interior glass ranges from a translucent cloudy brown to nearly opaque brown-gray. The opaque varieties seem to predominate.

Reduced nodules and flakes occur along Burro Creek, but in very low densities (<5 per 5m2). No other cultural material was recorded. References other than Moyer (1984. 1990) include Wilson and Moore (1959).

Elemental concentrations for Burro Creek source standards. All measurements in parts per million (ppm).

SAMPLE

Ti

Mn

Fe

Rb

Sr

Y

Zr

Nb

Ba

A 447.856 523.118 9574.586 397.376 7.443 82.471 106.38 48.459 42.534
B 467.263 472.8 9543.378 363.282 6.638 74.969 101.7 44.064 42.337
C 443.27 450.164 9322.295 359.243 5.398 75.256 100.365 50.158 42.626
D 510.451 503.48 9539.789 374.829 7.281 74.066 104.798 50.257 42.283
E 409.251 473.198 9055.937 372.791 5.808 80.875 102.66 54.106 41.903
F 481.486 508.869 9420.71 390.422 7.701 80.261 101.711 51.352 45.112
G 483.524 491.493 9335.461 386.442 7.296 80.669 106.894 46.714 43.189
H 458.911 442.12 8779.389 333.585 7.618 75.373 92.686 50.834 39.377
I 391.715 480.344 9640.976 383.091 6.793 79.091 103.219 48.695 42.708
J 428.097 438.867 9071.836 346.761 0 74.737 92.991 46.176 39.825
K 292.183 538.633 8636.567 343.839 4.582 68.367 103.211 40.266 42.838
L 223.775 555.114 8299.724 364.804 0 72.194 99.134 47.952 39.433
M 300.772 540.454 8689.754 366.699 6.508 68.476 100.05 45.742 41.305

REFERENCES

Moyer, T.C., 1984, The Pliocene Kaiser Spring (AZ) Bimodal Volcanic Field: Geology, Geochemistry, and Petrogenesis.  Ph.D. dissertation, Department of Geology, Arizona State University, Tempe.

Moyer, T.C., 1990, Generalized geologic map of the Kaiser Spring volcanic field, Mohave County, Arizona. Contributed Map CM-90-C, Arizona Geological Survey, University of Arizona, Tucson.

Wilson, E.D., and R.T. Moore, 1959, Geologic map of Mohave County, Arizona.  Bureau of Mines, Tucson, Arizona.

 

This page maintained by Steve Shackley (shackley@berkeley.edu).
Copyright 2015 M. Steven Shackley. All rights reserved.
Revised:19 August 2015

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