SUPERIOR

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

	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.