Table T9. Minerals identified by X-ray diffraction analysis, Hole 1188F.

Table T9. Minerals identified by X-ray diffraction analysis, Hole 1188F.

Core, section, interval (cm)

Unit

Description

XRD identification: major (minor, "trace") minerals*

Anhydrite (%)

193-1188F-

1Z-1, 4-5 27 Completely altered massive rock Quartz (anhydrite, illite, "pyrite")
5-10

1Z-1, 29-30 27 Completely altered massive rock Quartz (anhydrite, illite, pyrite)
2-5

1Z-1, 87-88 27 Completely altered massive rock Quartz (anhydrite, illite, pyrite)
5-10

1Z-2, 4-5 27 Completely altered massive rock Quartz (anhydrite, illite)
2-5

1Z-2, 37-38 27 Completely altered massive rock Quartz (anhydrite, illite, "pyrite")
5-10

1Z-3, 20-21 27 Completely altered massive rock Quartz (anhydrite, illite)
5-10

1Z-3, 34-35 27 Completely altered massive rock Quartz (anhydrite, illite)
10-15

1Z-3, 35-36 27 Completely altered massive rock (including anhydrite vein) Quartz (anhydrite, illite)
50-60

1Z-3, 85-86 28 Completely altered, silicified and green clay-bearing massive rock Quartz (chlorite, illite, anhydrite, pyrite)
<2

1Z-3, 106-108 28 Completely altered, silicified and green clay-bearing massive rock Quartz (anhydrite, illite, pyrite, "chlorite")
2-5

1Z-4, 90-91 28 Completely altered, silicified and green clay-bearing massive rock Quartz (anhydrite, illite, "pyrite")
5-10

2Z-1, 44-45 29 Completely altered, silicified aphyric massive rock Quartz (anhydrite, illite, pyrite)
2-5

2Z-1, 73-74 29 Completely altered, silicified aphyric massive rock Quartz, calcite (anhydrite, illite, "kaolinite?")
5-10

3Z-1, 6-7 29 Completely altered, silicified aphyric massive rock Quartz (illite, anhydrite, "pyrite")
<2

3Z-2, 40-41 30 Completely altered, brecciated, clay-rich rock Quartz (anhydrite, illite, pyrite)
10-15

3Z-2, 144-145 30 Completely altered, brecciated, clay-rich rock Quartz (anhydrite, chlorite, illite)
2-5

3Z-2, 150-151 30 Completely altered, brecciated, clay-rich rock Quartz (anhydrite, illite, pyrite)
10-15

6Z-1, 20-21 30 Completely altered, brecciated, clay-rich rock Quartz (anhydrite, illite, chlorite, pyrite)
<2

6Z-1, 46-47 31 Highly altered volcanic rock Cristobalite, plagioclase (chlorite, pyrite)
0

6Z-1, 77-78 32 Completely altered, silicified massive aphyric rock Quartz (anhydrite, illite)
2-5

6Z-2, 47-48 33 Silicified volcanic fragments embedded in soft gray clay Quartz (illite, pyrite, anhydrite)
<2

7Z-1, 41-45 34 Silicified massive aphyric rock Quartz (anhydrite, illite, "pyrite")
5-10

7Z-1, 104-107 35 Silicified, plagioclase-phyric rock Quartz (anhydrite, illite)
2-5

7Z-2, 3-6 35 Silicified, plagioclase-phyric rock Quartz (anhydrite, illite, "pyrite")
<2

8Z-1, 68-71 36 Silicified massive aphyric rock Quartz (anhydrite, illite)
5-10

9Z-1, 9-12 37 Silicified clastic rock Quartz (anhydrite, illite)
2-5

11G-1, 53-56 38 Silicified massive aphyric rock Quartz (anhydrite, illite, "pyrite")
5-10

11G-1, 138-141 39 Silicified plagioclase-phyric, slightly vesicular volcanic rock Quartz (anhydrite, pyrite, illite)
10-15

13Z-1, 118-121 41 Silicified plagioclase-phyric volcanic rock Quartz, anhydrite, pyrite, illite)
2-5

13Z-2, 51-55 41 Silicified plagioclase-phyric volcanic rock Quartz (anhydrite, illite, "pyrite")
5-10

13Z-2, 55-70 41 Silicified plagioclase-phyric volcanic rock Quartz (anhydrite, pyrite, illite, "chlorite")
2-5

14Z-1, 134-139 41 Silicified plagioclase-phyric volcanic rock Quartz (anhydrite, brittle mica?, pyrite)
2-5

15Z-1, 66-69 42 Silicified, aphyric rock Quartz (anhydrite, brittle mica?, pyrite)
2-5

15Z-1, 90-95 42 Silicified, aphyric rock Quartz (anhydrite, illite, brittle mica?, pyrite)
5-10

16Z-1, 41-43 44 Silicified, brecciated, flow banded, aphyric rock Quartz (illite, pyrite, "anhydrite")
<2

16Z-1, 139-141 44 Silicified, brecciated, flow banded, aphyric rock Quartz (pyrite, illite, brittle mica?, "anhydrite")
<2

22Z-1, 63-67 46 Completely altered, silicified, aphyric, volcanic rock Quartz (anhydrite, pyrite, illite, chlorite)
2-5

23Z-1, 25-26 48 White halo of Piece 3 Quartz (anhydrite, illite, pyrite, chlorite)
5-10

23Z-1, 26-27 48 Gray kernel of Piece 3 Quartz (chlorite, illite, pyrite, "anhydrite, smectite")
<2

23Z-1, 102-103 49 Silicified, green clay-bearing aphyric volcanic rock Quartz (anhydrite, chlorite, illite, "pyrite")
2-5

23Z-2, 13-14 49 White crust of Piece 2 (anhydrite vein) Anhydrite ("quartz")
>95

23Z-2, 24-25 49 Silicified, green clay-bearing, aphyric volcanic rock Quartz (anhydrite, chlorite, illite, pyrite)
2-5

23Z-2, 45-46 49 Silicified, green clay-bearing, aphyric volcanic rock Quartz (anhydrite, chlorite, illite, "pyrite")
2-5

25Z-1, 24-26 49 Silicified, green clay-bearing, aphyric volcanic rock Quartz, plagioclase (chlorite, pyrite, "anhydrite")
<2

26Z-1, 20-23 49 Silicified, green clay-bearing, aphyric volcanic rock Quartz (anhydrite, pyrite, illite, chlorite, chl/sm mixed-layer clays, "smectite")
5-10

26Z-2, 60-61 50 Silicified, plagioclase-phyric volcanic rock Quartz (chlorite, illite, anhydrite, pyrite)
2-5

27Z-1, 22-23 50 Silicified, plagioclase-phyric volcanic rock Quartz (anhydrite, pyrite, plagioclase, illite, chlorite)
2-5

30Z-1, 5-7 51 Completely altered, variably silicified breccia Quartz (plagioclase, illite, chlorite, "pyrite")
0

31Z-1, 1-3 52 Silicified, slightly plagioclase-magnetite phyric volcanic rock Quartz, plagioclase (chlorite, magnetite, pyrite, "anhydrite")
<2

31Z-1, 39-42 53 Completely altered, variably silicified breccia Quartz (pyrite, illite, chlorite, "anhydrite")
<2

34Z-1, 22-23 54 Completely altered aphyric volcanic rock Quartz (anhydrite, illite, pyrite, "plagioclase")
5-10

34Z-1, 27-28 55 Completely altered volcanic rock and breccia with variable black, late-stage magnetite-bearing alteration Magnetite (di- and trioctahedral illite, quartz, plagioclase, chlorite, pyrite, Fe spinel, "brucite")
0

34Z-1, 40-41 55 Completely altered volcanic rock and breccia with variable black, late-stage magnetite-bearing alteration Plagioclase, quartz (illite, chlorite, pyrite, magnetite, "illite-bearing mixed layer clays")
0

34Z-1, 89-90 56 Completely altered and variably silicified volcanic rock breccia Quartz (chlorite, illite, "anhydrite, pyrite")
<2

35Z-1, 5-6 57 Silicified, sparsely vesicular, aphyric, massive volcanic rock Quartz (plagioclase, pyrite, magnetite, illite, "anhydrite, chlorite")
<2

35Z-1, 46-48 57 Silicified, sparsely vesicular, aphyric, massive volcanic rock Quartz (plagioclase, pyrite, chlorite, "illite, anhydrite, magnetite")
<2

35Z-1, 140-141 57 Silicified, sparsely vesicular, aphyric, massive volcanic rock Quartz (anhydrite, illite, "pyrite, chlorite")
2-5

35Z-2, 48-49 57 Silicified, sparsely vesicular, aphyric, massive volcanic rock Quartz (anhydrite, illite, pyrite, "plagioclase")
2-5

37Z-1, 6-7 57 Silicified, sparsely vesicular, aphyric, massive volcanic rock Quartz, plagioclase (illite, "anhydrite, pyrite, magnetite, chlorite")
<2

37Z-2, 18-20 57 Silicified, sparsely vesicular, aphyric, massive volcanic rock Quartz (plagioclase, illite, pyrite, anhydrite, chlorite)
2-5

37Z-2, 31-33 58 Magnetite-rich, clastic rock Plagioclase (magnetite, illite, alunite, Fe spinel, chlorite, pyrite, brucite)
0

37Z-2, 65-68 59 Silicified, locally magnetite-bearing, aphyric volcanic rock Quartz (plagioclase, anhydrite, magnetite, "illite, chlorite, pyrite")
2-5

38Z-2, 90-92 61 Completely altered, aphyric, amygular volcanic rock Quartz, plagioclase (illite, chlorite, anhydrite, "pyrite, magnetite")
2-5

39Z-1, 7-8 62 Completely altered, sparsely plagioclase-phyric volcanic rock Quartz (anhydrite, illite, "chlorite, plagioclase, pyrite")
5-10

39Z-1, 41-43 62 Completely altered, sparsely plagioclase-phyric volcanic rock Quartz (anhydrite, illite, chlorite, "pyrite")
2-5

39Z-2, 18-19 64 Completely altered, aphyric volcanic rock Quartz (anhydrite, illite, chlorite, pyrite, plagioclase, illite-bearing mixed layer clays)
2-5

40Z-1, 3-5 65 Completely altered, magnetite-enriched, vesicular volcanic rock Quartz (plagioclase, anhydrite, illite, chlorite, pyrite, magnetite)
2-5

40Z-1, 36-38 66 Completely altered, sparsely plagioclase-phyric volcanic rock Quartz (anhydrite, illite, pyrite, "plagioclase, chlorite")
2-5

40Z-2, 35-36 67 Completely altered, clastic-textured volcanic rock Quartz (anhydrite, illite, pyrite, "plagioclase, chlorite")
2-5

41Z-1, 46-47 69 Completely altered, aphyric, amygdular volcanic rock Quartz (plagioclase, pyrite, illite, chlorite, "magnetite, anhydrite")
<2

41Z-2, 7-10 69 Completely altered, aphyric, amygdular volcanic rock Quartz (plagioclase, pyrite, illite, chlorite, "magnetite, anhydrite")
<2

42Z-1, 30-31 70 Completely altered, aphyric, sparsely amygdaloidal volcanic rock Quartz (anhydrite, illite, "pyrite")
5-10

42Z-1, 72-74 70 Completely altered, aphyric, sparsely amygdaloidal volcanic rock Quartz (anhydrite, chlorite, illite, pyrite, "plagioclase")
5-10

43Z-1, 6-8 71 Completely altered, aphyric, sparsely vesicular volcanic rock Quartz (illite, pyrite, chlorite, "anhydrite, plagioclase")
<2

43Z-1, 67-69 72 Completely altered, magnetite-bearing, aphyric volcanic rock Quartz, plagioclase (chlorite, pyrite, magnetite, "anhydrite")
<2

43Z-1, 90-91 72 Completely altered, magnetite-bearing, aphyric volcanic rock Quartz, plagioclase (chlorite, anhydrite, "pyrite, magnetite")
2-5

44Z-1, 85-86 72 Completely altered, magnetite-bearing, aphyric volcanic rock Quartz, plagioclase (chlorite, anhydrite, "pyrite, magnetite")
2-5

Core, section, interval (cm)	Unit	Description	XRD identification: major (minor, "trace") minerals*	Anhydrite (%)
193-1188F-
1Z-1, 4-5	27	Completely altered massive rock	Quartz (anhydrite, illite, "pyrite")	5-10
1Z-1, 29-30	27	Completely altered massive rock	Quartz (anhydrite, illite, pyrite)	2-5
1Z-1, 87-88	27	Completely altered massive rock	Quartz (anhydrite, illite, pyrite)	5-10
1Z-2, 4-5	27	Completely altered massive rock	Quartz (anhydrite, illite)	2-5
1Z-2, 37-38	27	Completely altered massive rock	Quartz (anhydrite, illite, "pyrite")	5-10
1Z-3, 20-21	27	Completely altered massive rock	Quartz (anhydrite, illite)	5-10
1Z-3, 34-35	27	Completely altered massive rock	Quartz (anhydrite, illite)	10-15
1Z-3, 35-36	27	Completely altered massive rock (including anhydrite vein)	Quartz (anhydrite, illite)	50-60
1Z-3, 85-86	28	Completely altered, silicified and green clay-bearing massive rock	Quartz (chlorite, illite, anhydrite, pyrite)	<2
1Z-3, 106-108	28	Completely altered, silicified and green clay-bearing massive rock	Quartz (anhydrite, illite, pyrite, "chlorite")	2-5
1Z-4, 90-91	28	Completely altered, silicified and green clay-bearing massive rock	Quartz (anhydrite, illite, "pyrite")	5-10
2Z-1, 44-45	29	Completely altered, silicified aphyric massive rock	Quartz (anhydrite, illite, pyrite)	2-5
2Z-1, 73-74	29	Completely altered, silicified aphyric massive rock	Quartz, calcite (anhydrite, illite, "kaolinite?")	5-10
3Z-1, 6-7	29	Completely altered, silicified aphyric massive rock	Quartz (illite, anhydrite, "pyrite")	<2
3Z-2, 40-41	30	Completely altered, brecciated, clay-rich rock	Quartz (anhydrite, illite, pyrite)	10-15
3Z-2, 144-145	30	Completely altered, brecciated, clay-rich rock	Quartz (anhydrite, chlorite, illite)	2-5
3Z-2, 150-151	30	Completely altered, brecciated, clay-rich rock	Quartz (anhydrite, illite, pyrite)	10-15
6Z-1, 20-21	30	Completely altered, brecciated, clay-rich rock	Quartz (anhydrite, illite, chlorite, pyrite)	<2
6Z-1, 46-47	31	Highly altered volcanic rock	Cristobalite, plagioclase (chlorite, pyrite)	0
6Z-1, 77-78	32	Completely altered, silicified massive aphyric rock	Quartz (anhydrite, illite)	2-5
6Z-2, 47-48	33	Silicified volcanic fragments embedded in soft gray clay	Quartz (illite, pyrite, anhydrite)	<2
7Z-1, 41-45	34	Silicified massive aphyric rock	Quartz (anhydrite, illite, "pyrite")	5-10
7Z-1, 104-107	35	Silicified, plagioclase-phyric rock	Quartz (anhydrite, illite)	2-5
7Z-2, 3-6	35	Silicified, plagioclase-phyric rock	Quartz (anhydrite, illite, "pyrite")	<2
8Z-1, 68-71	36	Silicified massive aphyric rock	Quartz (anhydrite, illite)	5-10
9Z-1, 9-12	37	Silicified clastic rock	Quartz (anhydrite, illite)	2-5
11G-1, 53-56	38	Silicified massive aphyric rock	Quartz (anhydrite, illite, "pyrite")	5-10
11G-1, 138-141	39	Silicified plagioclase-phyric, slightly vesicular volcanic rock	Quartz (anhydrite, pyrite, illite)	10-15
13Z-1, 118-121	41	Silicified plagioclase-phyric volcanic rock	Quartz, anhydrite, pyrite, illite)	2-5
13Z-2, 51-55	41	Silicified plagioclase-phyric volcanic rock	Quartz (anhydrite, illite, "pyrite")	5-10
13Z-2, 55-70	41	Silicified plagioclase-phyric volcanic rock	Quartz (anhydrite, pyrite, illite, "chlorite")	2-5
14Z-1, 134-139	41	Silicified plagioclase-phyric volcanic rock	Quartz (anhydrite, brittle mica?, pyrite)	2-5
15Z-1, 66-69	42	Silicified, aphyric rock	Quartz (anhydrite, brittle mica?, pyrite)	2-5
15Z-1, 90-95	42	Silicified, aphyric rock	Quartz (anhydrite, illite, brittle mica?, pyrite)	5-10
16Z-1, 41-43	44	Silicified, brecciated, flow banded, aphyric rock	Quartz (illite, pyrite, "anhydrite")	<2
16Z-1, 139-141	44	Silicified, brecciated, flow banded, aphyric rock	Quartz (pyrite, illite, brittle mica?, "anhydrite")	<2
22Z-1, 63-67	46	Completely altered, silicified, aphyric, volcanic rock	Quartz (anhydrite, pyrite, illite, chlorite)	2-5
23Z-1, 25-26	48	White halo of Piece 3	Quartz (anhydrite, illite, pyrite, chlorite)	5-10
23Z-1, 26-27	48	Gray kernel of Piece 3	Quartz (chlorite, illite, pyrite, "anhydrite, smectite")	<2
23Z-1, 102-103	49	Silicified, green clay-bearing aphyric volcanic rock	Quartz (anhydrite, chlorite, illite, "pyrite")	2-5
23Z-2, 13-14	49	White crust of Piece 2 (anhydrite vein)	Anhydrite ("quartz")	>95
23Z-2, 24-25	49	Silicified, green clay-bearing, aphyric volcanic rock	Quartz (anhydrite, chlorite, illite, pyrite)	2-5
23Z-2, 45-46	49	Silicified, green clay-bearing, aphyric volcanic rock	Quartz (anhydrite, chlorite, illite, "pyrite")	2-5
25Z-1, 24-26	49	Silicified, green clay-bearing, aphyric volcanic rock	Quartz, plagioclase (chlorite, pyrite, "anhydrite")	<2
26Z-1, 20-23	49	Silicified, green clay-bearing, aphyric volcanic rock	Quartz (anhydrite, pyrite, illite, chlorite, chl/sm mixed-layer clays, "smectite")	5-10
26Z-2, 60-61	50	Silicified, plagioclase-phyric volcanic rock	Quartz (chlorite, illite, anhydrite, pyrite)	2-5
27Z-1, 22-23	50	Silicified, plagioclase-phyric volcanic rock	Quartz (anhydrite, pyrite, plagioclase, illite, chlorite)	2-5
30Z-1, 5-7	51	Completely altered, variably silicified breccia	Quartz (plagioclase, illite, chlorite, "pyrite")	0
31Z-1, 1-3	52	Silicified, slightly plagioclase-magnetite phyric volcanic rock	Quartz, plagioclase (chlorite, magnetite, pyrite, "anhydrite")	<2
31Z-1, 39-42	53	Completely altered, variably silicified breccia	Quartz (pyrite, illite, chlorite, "anhydrite")	<2
34Z-1, 22-23	54	Completely altered aphyric volcanic rock	Quartz (anhydrite, illite, pyrite, "plagioclase")	5-10
34Z-1, 27-28	55	Completely altered volcanic rock and breccia with variable black, late-stage magnetite-bearing alteration	Magnetite (di- and trioctahedral illite, quartz, plagioclase, chlorite, pyrite, Fe spinel, "brucite")	0
34Z-1, 40-41	55	Completely altered volcanic rock and breccia with variable black, late-stage magnetite-bearing alteration	Plagioclase, quartz (illite, chlorite, pyrite, magnetite, "illite-bearing mixed layer clays")	0
34Z-1, 89-90	56	Completely altered and variably silicified volcanic rock breccia	Quartz (chlorite, illite, "anhydrite, pyrite")	<2
35Z-1, 5-6	57	Silicified, sparsely vesicular, aphyric, massive volcanic rock	Quartz (plagioclase, pyrite, magnetite, illite, "anhydrite, chlorite")	<2
35Z-1, 46-48	57	Silicified, sparsely vesicular, aphyric, massive volcanic rock	Quartz (plagioclase, pyrite, chlorite, "illite, anhydrite, magnetite")	<2
35Z-1, 140-141	57	Silicified, sparsely vesicular, aphyric, massive volcanic rock	Quartz (anhydrite, illite, "pyrite, chlorite")	2-5
35Z-2, 48-49	57	Silicified, sparsely vesicular, aphyric, massive volcanic rock	Quartz (anhydrite, illite, pyrite, "plagioclase")	2-5
37Z-1, 6-7	57	Silicified, sparsely vesicular, aphyric, massive volcanic rock	Quartz, plagioclase (illite, "anhydrite, pyrite, magnetite, chlorite")	<2
37Z-2, 18-20	57	Silicified, sparsely vesicular, aphyric, massive volcanic rock	Quartz (plagioclase, illite, pyrite, anhydrite, chlorite)	2-5
37Z-2, 31-33	58	Magnetite-rich, clastic rock	Plagioclase (magnetite, illite, alunite, Fe spinel, chlorite, pyrite, brucite)	0
37Z-2, 65-68	59	Silicified, locally magnetite-bearing, aphyric volcanic rock	Quartz (plagioclase, anhydrite, magnetite, "illite, chlorite, pyrite")	2-5
38Z-2, 90-92	61	Completely altered, aphyric, amygular volcanic rock	Quartz, plagioclase (illite, chlorite, anhydrite, "pyrite, magnetite")	2-5
39Z-1, 7-8	62	Completely altered, sparsely plagioclase-phyric volcanic rock	Quartz (anhydrite, illite, "chlorite, plagioclase, pyrite")	5-10
39Z-1, 41-43	62	Completely altered, sparsely plagioclase-phyric volcanic rock	Quartz (anhydrite, illite, chlorite, "pyrite")	2-5
39Z-2, 18-19	64	Completely altered, aphyric volcanic rock	Quartz (anhydrite, illite, chlorite, pyrite, plagioclase, illite-bearing mixed layer clays)	2-5
40Z-1, 3-5	65	Completely altered, magnetite-enriched, vesicular volcanic rock	Quartz (plagioclase, anhydrite, illite, chlorite, pyrite, magnetite)	2-5
40Z-1, 36-38	66	Completely altered, sparsely plagioclase-phyric volcanic rock	Quartz (anhydrite, illite, pyrite, "plagioclase, chlorite")	2-5
40Z-2, 35-36	67	Completely altered, clastic-textured volcanic rock	Quartz (anhydrite, illite, pyrite, "plagioclase, chlorite")	2-5
41Z-1, 46-47	69	Completely altered, aphyric, amygdular volcanic rock	Quartz (plagioclase, pyrite, illite, chlorite, "magnetite, anhydrite")	<2
41Z-2, 7-10	69	Completely altered, aphyric, amygdular volcanic rock	Quartz (plagioclase, pyrite, illite, chlorite, "magnetite, anhydrite")	<2
42Z-1, 30-31	70	Completely altered, aphyric, sparsely amygdaloidal volcanic rock	Quartz (anhydrite, illite, "pyrite")	5-10
42Z-1, 72-74	70	Completely altered, aphyric, sparsely amygdaloidal volcanic rock	Quartz (anhydrite, chlorite, illite, pyrite, "plagioclase")	5-10
43Z-1, 6-8	71	Completely altered, aphyric, sparsely vesicular volcanic rock	Quartz (illite, pyrite, chlorite, "anhydrite, plagioclase")	<2
43Z-1, 67-69	72	Completely altered, magnetite-bearing, aphyric volcanic rock	Quartz, plagioclase (chlorite, pyrite, magnetite, "anhydrite")	<2
43Z-1, 90-91	72	Completely altered, magnetite-bearing, aphyric volcanic rock	Quartz, plagioclase (chlorite, anhydrite, "pyrite, magnetite")	2-5
44Z-1, 85-86	72	Completely altered, magnetite-bearing, aphyric volcanic rock	Quartz, plagioclase (chlorite, anhydrite, "pyrite, magnetite")	2-5

Notes: XRD = X-ray diffraction. * = the terms major, minor, and trace are applied to XRD analyses as explained in "Hydrothermal Alteration" in the "Explanatory Notes" chapter and do not imply quantitative abundances. Anhydrite abundances are estimated for quartz-bearing assemblages as described in "Hydrothermal Alteration" in the "Explanatory Notes" chapter. This procedure probably results in an overestimation of the anhydrite abundance because the effect of clays is ignored. In the absence of a suitable calibration, it is not possible to estimate anhydrite abundance from XRD spectra. Chl/sm mixed-layer clays = chlorite/smectite-mixed layer clays.