Table 15. Trace element composition of Site 998 volcanic ash layers.
Notes: Shipboard XRF data given in parts per million. Ma = age of layers in millions of years.

Core, section, interval (cm)	Ma	Depth (mbsf)	Nb	Zr	Y	Sr	Rb	Zn	Cu	Ni	Cr	V	Ba

Ash layers:
165-998A-
13H-3, 25-27	7.6	118	9.9	95	1	273	24	49	1	187	18	507	165
13H-5, 118-120	7.7	121	7.6	70	1	230	17	22	1	90	1	31	86
14H-6, 16-18	8.7	132	12.9	293	1	392	21	69	23	134	1	47	500
16H-4, 106-109	10.3	148	16.1	118	22	250	149	29	3	46	1	13	917
19X-3, 54-57	13.7	171	5.8	140	16	158	92	40	7	26	1	12	721
19X-3, 54-57	13.8	171	4.5	128	11	235	78	51	10	47	1	20	600
20X-2, 9-11	14.3	179	12.3	177	39	76	130	42	6	9	1	4	660
20X-CC, 32-33	14.4	183.5	15.2	124	85	53	230	76	6	9	1	6	270
28X-4, 123-125	19.4	259	16.3	122	61	73	193	37	9	2	1	2	259
31X-3, 129-131	21.2	286	13.2	132	24	193	178	27	6	17	1	11	266
37X-1, 142-144	24.4	341	6.8	237	1	591	35	38	6	173	1	2	159
1R-7, 51-53	32.5	567	7.5	123	1	488	18	20	20	84	1	2	104
9R-4, 48-50	36.9	641	3.8	255	1	517	9	68	102	115	1	25	67
15R-4, 30-32	40.5	698	1	20	2	99	17	18	5	21	30	99	1173
28R-4, 53-55	46.7	815	0.8	33	8	522	17	39	28	30	22	30	187

Ash turbidites:
165-998B-
31R-CC, 5-7	49.3	847.3	1.9	81	8	489	35	61	199	97	83	151	325
32R-4, 37-40	50.2	853	1.5	59	6	609	37	48	75	72	48	92	480
35R-6, 68-71	52	884	0.6	45	5	460	26	40	30	25	41	70	370
35R-5, 109-111	52.1	883	1.9	63	6	408	44	46	45	319	59	131	195