Table 1.
Summary of drill sites of International Ocean Discovery Program (IODP) Exp. 385 (Teske et al., 2020, 2021) from which samples were used for this study.
| Site and Hole | Latitude and Longitude | Temperature gradient (°C km−1) | Seafloor depth (mbsl) | Number and depth range of samples | Site description |
|---|---|---|---|---|---|
| U1545C | 27°38.2420’N 111°53.3290’W |
225 | 1,595 | 21, 2.0–325.8 mbsf | About 52 km northwest of the western axial graben of the northern Guaymas Basin spreading segment, sediment strata are not disturbed by the intruding sill, 1.1 km distance to Site U1546D, mainly diatom ooze and clay. |
| U1546D | 27°37.8943’N 111°52.7812’W |
221 | 1,586 | 18, 2.1–292.4 mbsf | About 51 km northwest of the western axial graben, disturbed sedimentary layer due to the sill intrusion at approx. 350–430 mbsf, mainly diatom ooze and diatom clay. |
| U1548C | 27°30.2698’N 111°40.8476’W |
958 | 1,737 | 7, 1.9–59.8 mbsf | About 27 km northwest of the western axial graben, located at the outside of the active hydrothermal ringvent, mainly diatom ooze. |
| U1551B | 27°12.3832’N 111°13.1841’W |
100 | 1,844 | 5, 1.4–35.6 mbsf | About 29 km southeast of the western axial graben, the only sampling site from the southeastern region of Guaymas Basin among the eight sampling sites, and predominantly terrestrial silt and sand. |
| U1552B | 27°33.2885’N 111°32.9640’W |
262 | 1,841 | 5, 2.1–48.0 mbsf | About 20 km northwest of the western axial graben, cold seep seafloor, gas hydrate rich site, diatom/silty clay, and sandy silt. |
mbsl stands for meter below sea level and mbsf stands for meter below seafloor. See Supplementary Table S1 for a list of all SRR data.