RED HILL

Collections from Sections 4 through 11,14,15,17 R19W, T2S USGS Red Hill 7.5' Quad, northwest Catron County, New Mexico.

Red Hill is, perhaps, one of the most petrologically unique obsidians in the Southwest. The nodules are found within a conglomerate that consists mainly of basalt cobbles, some quartzite and very little rhyolite (see also Findlow and Bolognese 1982:56). Findlow and Bolognese state that the obsidian extends "over much of Catron County" (1982:56). While the context is a Quaternary basalt, the obsidian is apparently related to earlier Tertiary silicic eruptions of the Mogollon-Datil Formation in the area (Elston et al. 1976; Willard and Weber 1958). Nodule densities are very low, usually less than 5 per 25 m². The largest nodule recovered was 8 cm in diameter, but most of nodules were 5 cm or less. Nodules up to 25 cm are reported by Findlow and Bolognese (1982:56; in 1995 after recent grading we recovered a number of nodules over 8 cm in diameter). Cortical material varies from a thin gray or brown to glassy. The aphyric glass ranges from a nearly transparent brown (like Superior) to a cloudy or banded light gray. The knapping quality is excellent, equal to any in the Southwest. In August 2012 we recovered a number of nodules 7-10 cm at this same location after road grading. The would be similar to Findlow and Bolognese reporting in 1982.

Bipolar reduction stations and isolated flakes commonly occur, but in very low densities commensurate with the low geologic density. A few biface preform fragments were recorded, all less than 5 cm in length. References are those noted above.

Raw elemental concentrations for Red Hill source standards. All measurements in parts per million (ppm). RH samples collected in 1986 and 1995. 082912 prefixes collected in August 2012.

SAMPLE	Ti	Mn	Fe	Rb	Sr	Y	Zr	Nb	Ba¹
RH1	399	682	7335	183	14	41	72	48
RH2	353	804	7682	222	6	49	74	58
RH3	302	590	6522	164	12	34	67	48
RH4	417	820	8240	186	14	37	71	52
RH5	275	524	6020	174	5	41	67	59
RH6	397	595	6803	166	12	36	65	50
RH7	379	597	7010	176	12	40	68	48
RH8	365	445	5986	138	12	32	61	40
RH9	390	596	6709	171	12	37	68	51
RH10	391	614	7050	167	11	37	71	48
RH11	373	582	7023	163	12	35	68	47
RH12	340	609	6780	171	15	35	67	46
RHD	294	792	7443	216	9	46	74	66
RHE	377	587	6989	170	11	36	67	46
082912-1-1	795	544	7985	164	17	33	65	50
082912-1-2	914	669	9371	206	11	47	69	63	0
082912-13	824	502	7840	159	15	36	60	51	21
082912-1-4	886	716	9239	193	18	39	69	53	0
082912-1-5	791	571	8065	168	15	36	64	47	21
082912-1-6	805	491	7624	153	14	38	59	48	0
082912-1-7	808	504	7861	159	17	36	61	49	4
082912-1-8	952	578	8709	170	17	34	62	48	35
082912-1-9	1099	627	10040	176	20	39	65	50	9
082912-1-10	791	655	9265	203	12	47	74	58	12
082912-1-12	854	716	9032	204	9	52	68	61	42
082912-1-13	878	666	9149	208	12	47	68	61	9
082912-1-14	980	546	8889	166	19	36	64	49	8
082912-1-15	837	543	8141	164	15	40	62	49	0
082912-1-16	799	492	7686	152	14	35	65	50	33
082912-1-17	775	596	8309	197	12	48	66	65	9
082912-1-18	855	606	8756	177	17	41	65	51	34
082912-1-19	944	494	8618	155	17	33	68	52	4

	N	Minimum	Maximum	Mean	Std. Deviation
Ti	32	275	1099	645	263.7
Mn	32	445	820	605	92.8
Fe	32	5986	10040	7880	1036.0
Rb	32	138	222	176	20.2
Sr	32	5	20	13	3.5
Y	32	32	52	39	5.3
Zr	32	59	74	67	3.9
Nb	32	40	66	52	6.1
Ba	17	0	42	14	14.1

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

Sample	SiO₂	Al₂O₃	CaO	Fe₂O₃	K₂O	MgO	MnO	Na₂O	TiO₂
082912-1-5	78.159	12.051	0.698	0.786	4.507	<.001	0.117	3.498	0.062
RGM1-S4	75.680	12.477	1.3024	1.806	4.550	<.001	0.0379	3.77	0.196