TABLE 1.
Physical and chemical characteristics of, and Arthrobacter isolates from, Hanford YBB sediment samples
| Lithofacies and depth interval (m) | Sediment sample | pHa | Ehb (mV) | NO3 (mg liter−1) | PO4 (mg liter−1) | SO4 (mg liter−1) | TOC (mg kg−1) | % Clay/ % silt/ % sand | Hydraulic conductivity (cm s−1) | Isolate(s) |
|---|---|---|---|---|---|---|---|---|---|---|
| Lacustrine unit | ||||||||||
| 172.9–173.8 (oxidized layer) | G1 | 7.8 | NDc | 2.53 | <0.10 | 12.43 | 300 | 18/76/6 | <1.0 × 10−9 | G960, G961, G964, G965, ZAT001, ZAT004, ZAT005, ZAT012, ZAT013 |
| 173.8–174.3 | G2 | 8.0 | ND | 3.71 | 0.55 | 14.08 | 310 | 19/79/2 | <1.0 × 10−9 | |
| 174.5–175.2 | G3 | 8.7 | 200 | 2.37 | <0.10 | 8.61 | 9,610 | 29/68/3 | ND | ZAT014 |
| 176.2–176.9 | G5 | 8.7 | 260 | 1.64 | <0.10 | 5.5 | 10,480 | 38/53/9 | ND | G962, G969, ZAT255 |
| 177.1–177.5 | G6 | 8.1 | ND | 1.45 | <0.10 | 4.68 | 11,690 | 33/56/11 | 2.9 × 10−7 | G915 |
| 177.5–178.4 | G7 | 8.4 | 200 | 1.46 | <0.10 | 3.94 | 10,860 | 41/57/2 | 5.7 × 10−8 | G963, G970 |
| 178.6–179.3 | G8 | 8.5 | 180 | 1.35 | <0.10 | 4.03 | 8,440 | 34/64/2 | ND | |
| 179.4–180.2 | G9 | 8.6 | 150 | 2.07 | <0.10 | 7.56 | 9,700 | 45/55/0 | ND | G966, G980 |
| 180.3–181.0 | G10 | 8.8 | 150 | 2.31 | <0.10 | 7.50 | 7,760 | 28/71/1 | 1.6 × 10−8 | G968, G979, ZAT200 |
| 181.1–181.6 | G11 | 8.5 | 160 | <0.03 | <0.10 | 23.07 | 8,250 | 28/72/0 | ND | |
| 181.8–182.3 | G12 | 8.7 | 130 | 2.11 | <0.10 | 12.15 | 6,500 | 30/70/0 | ND | |
| 182.3–183.0 | G13 | 8.9 | 190 | <0.03 | <0.10 | 17.41 | 6,190 | 29/71/0 | ND | ZAT262, ZAT263 |
| 183.1–183.9 | G14 | 8.8 | 180 | 4.94 | <0.10 | 15.55 | 5,370 | 36/64/0 | ND | ZAT351, ZAT352 |
| 184.6–184.8 | G16A | 9.0 | 160 | 0.14 | <0.10 | 73.38 | 12,180 | 35/63/2 | 1.1 × 10−7 | |
| Upper paleosol unit | ||||||||||
| 184.8–184.8 (tefra) | G16T | 9.5 | ND | ND | ND | ND | ND | 36/20/44 | 1.1 × 10−7 | ZAT277 |
| 184.8–185.0 | G16B | 8.6 | 160 | 2.91 | <0.10 | 3.64 | ND | 15/52/33 | 1.1 × 10−7 | |
| 185.2–186.0 | G17 | 7.0 | 50 | 1.88 | <0.30 | 41.33 | 870 | 35/58/7 | ND | |
| 186.1–186.9 | G18 | 7.6 | 50 | 2.45 | <0.10 | 72.62 | 990 | 45/52/3 | ND | |
| 187.5–188.4 | G20 | 7.3 | 80 | 0.48 | <0.10 | 140.1 | 2,090 | 51/34/15 | ND | |
| 188.7–189.6 | G21 | 6.3 | 80 | <0.03 | <0.10 | 202.2 | 7,410 | 10/75/15 | 4.5 × 10−7 | ZAT031 |
| 191.7–192.1 | G25 | 8.1 | 300 | <0.03 | <0.10 | 11.47 | 1,300 | 10/13/77 | ND | |
| 192.2–192.7 | G26 | 7.0 | 320 | 17.17 | <0.01 | 39.81 | 660 | 22/61/17 | <1.0 × 10−9 | |
| Fluvial sands unit | ||||||||||
| 192.9–193.6 | G27 | 6.6 | 300 | 3.01 | <0.10 | 12.58 | 250 | 36/29/35 | <1.0 × 10−9 | |
| 193.9–194.6 | G28 | 7.3 | 290 | 2.81 | <0.10 | 17.89 | 250 | 10/52/38 | ND | |
| 195.0–195.6 | G29 | 7.5 | 290 | 1.99 | <0.10 | 16.43 | 230 | 8/33/59 | ND | |
| 195.8–196.3 | G30 | 7.3 | 290 | <0.03 | <0.10 | 15.77 | 180 | 10/16/74 | 8.8 × 10−7 | |
| 196.3–197.0 | G31 | 8.8 | 290 | 2.06 | <0.10 | 15.00 | 460 | 10/40/50 | ND | G954, G986, G991 |
| Fluvial gravel unit | ||||||||||
| 197.6–197.7 | G33 | 7.0 | 280 | <0.03 | <0.10 | 10.97 | 160 | ND | ND (10−4)d | G919, G982, G984, G993 |
| 211.3–211.7 | G34 | ND | ND | ND | ND | ND | ND | ND | ND | |
| Lower paleosol unit | ||||||||||
| 217.5–217.7 | G37 | ND | ND | ND | ND | ND | ND | ND | ND | G950, G959, ZAT054, ZAT055, ZAT056 |
| 222.2–223.0 | G40 | ND | ND | 3.56 | <0.07 | 19.52 | ND | ND | ND |
a
Of expressed porewater.
b
Of slurry.
c
ND, not determined.
d
No data are available for the hydraulic conductivity of this fluvial gravel sequence, but a measurement within the fluvial gravel sequence overlying the lacustrine is on the order of 10−4 cm s−1, and this stratum is likely to have a similar permeability.