Table 2. Multielement x-ray photoelectron spectroscopy analyses of core 1b and a surface sample from the gunshield.

Depth, mm	Total S	S reduced*	Sulfoxide	Sulfate	Fe	C	O	B
7.5	0.78	0.68 (87%)	0.04	0.05	0.20	27.2	6.4	0.17
10	0.66	0.56 (85%)	0.03	0.08	0.19	27.1	6.8	0.19
15	0.89	0.77 (87%)	0.05	0.07	0.17	26.0	7.5	0.18
33	0.81	0.71 (88%)	0.05	0.05	0.06	26.6	7.2	0.14
34	0.74	0.66 (89%)	0.03	0.05	0.18	31.7	2.3	0.05
45	0.70	0.60 (86%)	0.06	0.04	0.21	30.0	4.0	0.12
60	0.64	0.58 (89%)	0.04	0.05	–	24.4	10.0	0.13
75	0.64	0.51 (80%)	0.05	0.08	0.28	26.5	7.5	0.14
89	0.69	0.63 (91%)	0.07	0.03	0.02	23.2	11.0	0.19
92.5	0.77	0.49 (61%)	0.12	0.16	0.4	26.8	7.0	0.07
99	0.68	0.59 (87%)	0.05	0.05	0.14	23.5	10.1	0.11
104	0.65	0.50 (77%)	0.07	0.08	0.51	29.8	4.0	0.09
112	0.72	0.54 (67%)	0.08	0.09	0.34	28.2	5.6	0.11
144	0.80	0.70 (87%)	0.03	0.07	–	23.8	10.3	0.26
Gunshield	3.5	0.60 (17%)	0.07	2.8	2.8	16.3	13.2	–

Values are in mass %. The mass % scale was obtained by assuming two hydrogen atoms per carbon.

^*Values in parentheses represent the percentage of sulfur in reduced species