Table T1. Results of X-ray diffraction analyses, <2-µm size fraction, Hydrate Ridge, Cascadia margin.
Core, section,
interval top (cm)
Depth
(mbsf)
Unit
Age
(Ma)
X-ray diffraction peak area
(total counts)
Relative %
(Biscaye factors)
Illite/smectite
mixed-layer clay
Smectite
(001)
Illite
(001)
Chlorite
(002)
Smectite
Illite
Chlorite +
kaolinite
S(001)
saddle
S(001)
peak
Saddle/
peak
%
Expand
204-1244C-
6H-5, 135 50.71 I <0.27 21,044 6,283 18,690 25 30 45 347 488 0.71 63
11H-5, 135 97.58 II 0.46–1.00 42,460 9,089 25,030 33 28 39 372 637 0.58 68
19X-5, 85 149.85 II 0.46–1.00 49,875 8,805 24,592 37 26 37 456 791 0.58 69
25X-3, 135 200.75 II 0.46–1.00 40,320 11,469 26,427 29 33 38 386 594 0.65 66
30X-3, 130 249.00 III 1.59–1.67 32,274 5,450 15,047 38 26 36 375 567 0.66 65
35X-3, 130 297.33 III 1.70–2.78 41,484 7,304 19,166 38 27 35 432 667 0.65 66
37X-1, 130 313.50 III 1.70–2.78 34,141 6,442 16,352 37 28 35 320 533 0.60 68
38X-3, 130 326.20 III >2.78 30,781 4,537 17,166 37 22 41 335 534 0.63 67
39X-1, 130 332.80 III >2.78 21,260 3,222 8,617 41 25 34 300 413 0.73 62
204-1245B-
6H-2, 140 50.40 II <0.27 29,597 9,029 27,403 25 30 45 392 571 0.69 64
11H-5, 140 101.87 III 0.46–1.00 36,155 8,186 20,842 33 30 38 406 633 0.64 66
18X-2, 113 151.73 III 1.00–1.20 36,226 11,712 24,471 27 35 37 460 647 0.71 63
23X-5, 125 201.95 III 1.00–1.20 29,563 6,448 19,042 32 28 41 310 500 0.62 67
28X-2, 125 245.68 IV 1.00–1.20 59,522 11,029 23,056 40 29 31 451 817 0.55 70
35X-2, 125 303.55 IV 1.20–1.59 28,799 8,833 23,892 26 32 43 355 515 0.69 64
40X-2, 125 351.65 IV 1.20–1.59 19,369 5,846 15,793 26 31 42 335 441 0.76 60
45X-2, 125 399.85 IV 1.20–1.59 29,402 5,431 14,572 37 27 36 356 508 0.70 63
51X-2, 125 447.95 V 1.20–1.59 39,408 6,561 15,892 40 27 33 383 599 0.64 66
52X-2, 125 457.45 V 1.20–1.59 53,495 8,341 19,270 43 27 31 469 760 0.62 67
53X-2, 125 466.51 V 1.20–1.59 42,499 8,080 20,540 37 28 35 344 583 0.59 68
204-1245E-
4R-1, 130 502.20 V 1.20–1.59 20,093 4,133 10,295 35 29 36 289 395 0.73 62
5R-1, 122 511.72 V 1.20–1.59 19,585 4,458 11,149 33 30 37 312 413 0.76 60
6R-1, 85 521.05 V >1.59 19,006 5,760 13,175 28 34 39 307 401 0.77 60
7R-1, 132 531.12 V >1.59









204-1246B-
6H-5, 140 50.00 II <0.27 26,559 5,733 16,973 32 27 41 312 493 0.63 66
12H-2, 140 102.60 II 0.27–0.46 18,820 4,622 15,481 28 27 45 312 426 0.73 62
15H-2, 140 125.15 II >0.46 14,032 5,456 16,848 20 31 48 298 365 0.82 57
15H-4, 140 128.15 II >0.46 18,926 5,323 15,908 26 30 44 297 400 0.74 61
16H-2, 140 132.70 II >0.46 19,886 9,136 21,797 20 37 44 349 454 0.77 60
204-1247B-
20X-3, 130 148.50 III 1.00–1.20 32,407 6,423 20,304 33 26 41 398 606 0.66 65
25X-3, 130 196.33 III >1.59 37,749 7,314 21,082 35 27 39 421 657 0.64 66
26X-3, 130 206.20 III >1.59 31,746 7,017 18,840 33 29 39 388 582 0.67 65
27X-3, 130 215.50 III >1.59 12,636 6,719 12,304 20 42 38 289 343 0.84 55
204-1248C-
6H-3, 129 51.05 III 0.46–1.59 30,280 7,918 20,392 29 31 40 386 571 0.68 64
11H-4, 122 100.36 III 0.46–1.59 9,975 4,386 11,475 20 35 45 242 288 0.84 55
16H-3, 135 140.85 III >1.59 24,306 7,360 19,525 26 32 42 339 496 0.68 64
17X-1, 130 143.30 III >1.59 42,441 8,980 20,923 35 30 35 420 671 0.63 67
17X-3, 135 146.30 III >1.59 31,389 6,228 16,051 36 28 36 372 571 0.65 66
204-1250C-
6H-5, 118 48.95 III <0.27 22,729 6,292 15,617 29 32 39 350 463 0.76 60
13H-2, 130 103.19 III >1.59 19,172 6,051 15,060 26 33 41 323 438 0.74 61
17H-3, 130 136.30 III >1.59 22,053 6,295 18,175 26 30 43 276 419 0.66 65
19X-2, 130 141.30 III >1.59 29,448 6,701 19,881 31 28 41 344 511 0.67 65
19X-5, 130 145.75 III >1.59 21,762 6,466 18,000 26 31 43 339 448 0.76 60
204-1250F-
11X-2, 98 155.68 III >1.59 28,195 7,403 19,054 29 31 40 348 509 0.68 64
12X-3, 125 167.05 III >1.59 25,108 5,751 17,107 30 28 42 364 504 0.72 62
13X-3, 125 176.65 III >1.59 31,789 5,466 15,459 38 26 37 380 575 0.66 65
204-1251B-
6H-5, 131 53.61 I 0.09–0.27 6,488 2,756 4,312 25 42 33 222 254 0.87 52
11H-5, 70 100.61 I 0.09–0.27 27,421 8,463 21,510 26 32 41 290 433 0.67 65
17H-5, 80 150.90 II 0.27–0.46 20,631 7,740 19,104 23 34 43 280 402 0.70 64
26X-2, 130 207.00 II 0.46–1.00 23,355 6,905 19,080 26 31 43 330 452 0.73 62
30X-4, 110 248.00 II 0.46–1.00 18,188 5,614 15,975 25 31 44 317 425 0.75 61
36X-5, 80 299.40 II 1.59–1.67 41,547 8,092 20,836 36 28 36 412 651 0.63 66
49X-3, 130 402.20 III 1.7–2.0 27,024 3,802 10,390 43 24 33 320 471 0.68 64
51X-3, 130 420.50 III 1.7–2.0 39,292 6,029 18,865 39 24 37 401 631 0.64 66
52X-3, 130 430.10 III 1.7–2.0 33,853 5,976 13,990 39 28 33 367 569 0.64 66
53X-3, 130 439.78 III >2.0 36,342 7,948 19,810 34 30 37 348 570 0.61 67