SUPERIOR (PICKETPOST MOUNTAIN)

CENTRAL ARIZONA

The Picketpost Mountain source is located in Tonto National Forest (and private land), northeast Pinal County, Arizona.  The Superior obsidian locality is one of the most well-known glass sources in the Southwest (Reynolds et al. 1986).  The perlite here was mined historically and "Apache Tears" have been sold by individuals owning land on the source.

At Superior, the nodules are definitely marekanite remnants eroding from perlite.  Reynolds et al. exhibit a photograph of marekanites embedded in the perlite matrix (1986:Figure 9).  Nodules are most common on the east slope of Picketpost Mountain within a rhyolite/perlite regolith and in small washes eroding north into Queen Creek and a considerable distance west through the Queen Creek drainage.  No nodules were recorded embedded within perlite in the 1980s, but marekanites were recovered with perlite still attached.  Nodule densities are up to 20 per m2, but the nodule sizes are generally less than 5 cm in diameter.  Some were 'on sale' that approach 8 cm.  The density and nodule size recorded are probably skewed by the heavy collection that has occurred here in recent years. Cortical material is primarily a thin whitish perlite, with black glass showing through.  The aphyric glass is consistently nearly transparent brown; a few nodules show some banding.  The glass is an excellent knapping material, second to none in the Southwest.

Reduction of the nodules is actually uncommon at the source.  This may be due to common prehistoric knowledge concerning the consistent good quality.  Hankat Cave (AZ U:16:6 ASU), an Archaic period rockshelter about 20 km south exhibited a relatively large proportion of cores, flakes, debitage, and bifaces of Superior obsidian in the assemblage (Ackerly 1986).  Many reduced nodules and Archaic projectile points were less than 5cm in diameter, suggesting that the nodule size found today may not be too different than during the Archaic period.  The source material does appear in other Archaic through Preclassic Hohokam contexts throughout central Arizona (Shackley 2005).  Indeed, in the pre-Classic contexts at Snaketown and the Grewe Site, Superior was the preferred material for what Hoffman (1997) refers to as utilitarian projectile points called Snaketown Serrated (see Shackley 2005). At AZ U:11:252 (ASM) located along Queen Creek downstream from Picketpost Mountain, the entire obsidian assemblage was from that source, and the entire production trajectory was evident from unreduced nodules, to early to late stage Snaketown Serrated preforms to finished projectile points (Shackley 2005:156-161; Wegener et al. 2002).  Many of the finished projectile points are virtually identical to those produced at the Grewe Site (AZ U:2:2 ASM) not far west called by Marshall Class 1 and 2 points (Marshall 2001).  Whether AZ U:11:252 was an extractive site for Grewe Site toolmakers and hunters will never be known for certain (see Wegener et al. 2002).

During the Classic in the Gila, Salt, and Tucson Basins, access to Superior was evidently restricted, probably by the Salado, and other sources such as Sauceda Mountains became more common at all sites (Shackley 2005). This doesn't seem to be the case in the Tucson Basin where Superior remained common in lithic assemblages.  Reynolds et al. (1986), Wilson and Roseveare (1945); Wilson and Moore (1959) and the above are references for this source.

The two sources in central Arizona that are most frequently recovered in Arizona sites are Superior and Vulture. It is crucial to discriminate these sources, particularly in sites dating to the Sedentary (Sacaton) Period Hohokam where Superior is dominant in sites along the Middle Gila River, such as Snaketown and Grewe, while Vulture is dominant in sites along the Lower Salt River, and deviations from this pattern point to exchange likely through the market system employed through the ball games (Shackley 2005).  The two sources can be discriminated using Rb, Sr, Zr, and Ba.  The best discrimination is through plotting using the elements Zr and Ba (see below).

Ba versus Zr bivariate plot of Superior (Picketpost Mountain) and Vulture source standards

Raw elemental concentrations for 64 Superior (Picketpost Mtn) source standards and USGS RGM-1 obsidian standard. All measurements in parts per million (ppm).

SAMPLE Ti Mn Fe Zn Rb Sr Y Zr Nb Ba
1             765 496 7868   131 21 27 99 35 237
2             709 456 7518   126 20 24 96 32 239
3             808 498 7860   129 16 21 101 32 255
4             756 493 7786   128 16 25 98 33 250
5             831 473 7708   130 19 23 105 29 239
6             778 478 7927   133 21 24 94 32 251
7             796 500 7827   130 22 29 100 33 242
8             899 537 8175   136 20 25 101 35 242
9             718 479 7915   128 19 26 101 30 245
10            829 479 7870   130 18 26 100 35 249
11            796 504 8065   133 20 27 100 33 240
12            1298 491 8022   128 16 26 101 31 241
13            832 475 7810   130 20 24 102 32 239
14         119 20 24 100 30 196
15         117 19 25 98 30 207
16         120 21 24 100 31 198
17         115 19 24 97 30 158
18         116 19 25 98 30 180
19         115 19 24 100 30 161
20         112 18 25 100 30 176
21         107 20 24 99 29 191
22         110 19 22 97 29 169
23         119 19 25 104 31 167
24         111 18 25 99 30 156
25 968 362 7096   102 19 24 83 25 212
26 914 348 7125   104 17 21 87 30 314
JB11 989 518 8298 40 122 21 26 93 33 231
JB2 1074 548 8511 60 124 18 24 100 24 237
JB3 1068 470 8459 48 118 22 27 94 33 221
JB4 1043 479 8078 46 122 22 24 95 34 230
JB5 1416 551 10763 55 125 26 25 97 33 213
JB6 1010 502 8311 50 124 19 26 93 32 219
JB7 1015 496 8241 52 123 23 27 94 33 255
JB8 960 479 8154 45 123 19 23 96 35 249
JB9 1017 455 8238 42 118 20 27 91 30 192
JB10 989 433 7685 50 113 21 23 89 32 168
JB11 937 424 7612 43 111 21 23 91 25 231
JB12 1041 479 8363 48 120 23 25 94 33 194
JB13 1020 471 8095 44 122 21 22 101 31 220
JB14 991 482 8122 47 120 21 25 96 29 211
JB15 1056 459 8072 49 115 20 27 96 29 233
JB16 946 498 8072 40 125 23 24 95 30 234
JB17 979 459 8087 43 123 20 26 92 31 230
JB18 1351 485 9094 48 120 23 20 96 31 255
JB19 1051 517 8364 50 125 23 25 95 30 214
JB20 989 448 7890 38 118 21 25 93 34 208
JB21 1372 696 9972 53 125 23 21 97 34 220
JB22 1015 466 7948 45 115 22 24 94 30 247
JB23 987 468 8216 45 118 23 28 94 28 225
JB24 1003 521 8365 51 120 19 25 93 29 220
JB25 963 428 7782 43 109 20 24 86 29 199
JB26 1082 529 8697 54 131 24 25 93 32 205
JB27 1045 516 8547 69 126 22 26 95 33 234
JB28 1207 573 9427 50 127 23 26 94 30 225
JB29 1036 476 8007 45 118 21 24 93 31 224
JB30 899 398 7417 39 106 19 22 87 24 215
JB31 1048 488 8243 57 124 23 26 93 38 175
JB32 1164 525 9152 57 123 22 25 103 34 204
JB33 1644 545 11132 57 123 24 27 102 33 253
JB34 952 457 7822 46 119 19 23 92 33 199
JB35 1026 530 8385 76 126 22 25 91 32 227
JB36 994 466 8100 54 123 20 26 92 33 186
JB37 1004 492 8120 46 124 21 22 94 30 244
JB38 1069 503 8234 53 126 22 25 92 31 227
RGM1-S4 1600 277 13366 36 146 106 28 220 9 805

1 Samples with prefix "JB" are from the Jesse Ballenger collection from the Harborlite Perlite Mine at Picketpost Mountain

 

Mean and central tendency for data above 

 

N

Minimum

Maximum

Mean

Std. Deviation

Ti

53

709

1644

1003

176.7

Mn

53

348

696

487

51.3

Fe

53

7096

11132

8239

734.2

Zn

38

37

75

49

7.8

Rb

64

102

136

121

7.4

Sr

64

16

26

21

2.0

Y

64

20

29

25

1.7

Zr

64

83

105

96

4.5

Nb

64

24

38

31

2.6

Ba

64

156

314

219

29.6

 

MAJOR AND MINOR OXIDE DATA FOR SUPERIOR AND ANALYSIS OF RGM-1 USGS SOURCE STANDARD 

Sample

SiO2

Al2O3

CaO

Fe2O3

K2O

MgO

MnO

Na2O

TiO2

25

77.10

11.690

0.653

0.7879

5.947

0

0.0884

3.28

0.118

RGM1-S4

73.92

12.897

1.383

2.191

4.899

0

0.0375

4.15

1.262

 

 

References

 

Ackerly, N.W., 1986, Archaic Adaptive Strategies in the Middle Gila River Basin.  Ph.D. dissertation, Department of Anthropology, Arizona State University, Tempe.

 

Hoffman, C.M., 1997, Alliance Formation and Social Interaction During the Sedentary Period: A Stylistic Analysis of Hohokam Arrowpoints.  Ph.D. dissertation, Department of Anthropology, Arizona State University, Tempe.

 

Marshall, J.T., 2001, Flaked Stone Artifacts.  In D.B. Craig (Ed.) The Grewe Archaeological Research Project, Vol. 2: Material Culture, Part II: Stone, Shell, Bone Artifacts and Biological Remains.  Anthropological Papers 99-1, Northland Research, Flagstaff and Tempe, Arizona.

 

Reynolds, S.J., J.W. Welty, and J.E. Spencer, 1986, Volcanic History of Arizona.  Arizona Bureau of Geology and Mineral Technology Fieldnotes 16:1-5.

 

Shackley, M.S., 2005, Obsidian: Geology and Archaeology in the North American Southwest.  Tucson: University of Arizona Press.

 

Wegener, R.M., R. Ciolek-Torrello, and W.L. Deaver, 2002, Preliminary report of archaeological investigations along U.S. 60 at Florence Junction, Pinal County, Arizona.  SRI Technical Report 02-51, Tucson.

 

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

 

Wilson, E.D., and G.H. Roseveare, 1945, Arizona Perlite.  Arizona Bureau of Mines Circular 12, University of Arizona, Tucson.

 

 

This page maintained by Steve Shackley (shackley@berkeley.edu).
Copyright 2015 M. Steven Shackley. All rights reserved.
Revised: 27 December 2015

Back to the SW obsidian source page

To the EDXRF Lab home page