| Unit/Subunit | Core interval | Depth (mbsf) |
Thickness (m) |
Age | Lithologies
with volcanic components |
Volcanic components |
Authigenic
and secondary minerals |
|---|---|---|---|---|---|---|---|
| Lithologic | |||||||
| I-V | 1R-1, 0 cm, to 49R-1, 109 cm | 0 | 272.01 | early Pleistocene to late Eocene | Bathyal to neritic and shallow marine fossiliferous sediments | Disseminated and discrete tephra horizons, accumulations of terrigenous detritus, may be biologically disturbed (e.g., by burrowing) | Clay minerals after volcanic glass, zeolites (clinoptilolite), and glauconite |
| Basement | |||||||
| 1A | 49R-1, 109 cm, to 52R-1, 56 cm | 461.69 | 1.59 | >late Eocene | Massive and flow-banded felsic volcanic cobbles | Massive, flow-banded, altered and silicified, abraded, loose rhyolite lava cobbles and pebbles | Clay minerals after volcanic glass, followed by silicification |
| 1B | 52R-1, 56 cm, to 52R-1, 103 cm | 489.66 | 0.47 | >late Eocene | Bioclastic sandstone | Intercalated nonvolcanic lens with angular bioclasts (e.g., bryozoan, bivalve, echinoderm, benthic foraminifer), | |
| <1% volcanic lithic fragments | Clay minerals, hematitic staining | ||||||
| 1C | 52R-1, 103 cm, to 53R-1, 25 cm | 490.13 | 0.72 | >late Eocene | Pumice/flow-banded felsic breccia | Altered breccia, pale green, flow-banded clasts with banded perlite formation, in siliceous matrix | Pale green clay minerals (nontronite, kaolinite?), followed by silicification |
| 1D | 53R-1, 25 cm, to 54R-1, 0 cm | 499.05 | 2.49 | >late Eocene | Altered, perlitic felsic glass | Reddish orange, massive, felsic volcanic glass, well-developed spheroidal perlitic fractures, minor lithic volcanic fragments | White and pale green clay minerals (nontronite?), and silicification |
| 1E | 54R-1, 0 cm, to 55R-1-0 cm | 508.00 | 1.08 | >late Eocene | Sheared and altered volcaniclastic sediments (fault zone) | Green, resinous to powdery, highly altered sheared rock (Fault Zone), and less altered, sheared rock with clastic texture | Pale to dark green, resinous to powdery clay minerals |
| 2 | 55R-1, 0 cm, to 56R-1, 78cm | 517.60 | 1.51 | >late Eocene | Dark red welded vesicular rhyolite | Welded, dark red, vesicular, sandine?-rich rhyolite agglutinate | Hematite staining of clay minerals (smectite?), and silicification |
| 3 | 56R-1, 78 cm, to 57R-1, 92 cm | 528.08 | 4.63 | >late Eocene | Green, altered, crystal vitric tuff-breccia | Green, highly altered, sanidine-rich vitric rhyolite tuff breccia, incorporated flow-banded clasts and lithic fragments | Pale green clay minerals |
| 4 | 57R-1, 92 cm, to 60R-2, 54 cm | 537.82 | 6.54 | >late Eocene | Dark red welded vesicular rhyolite | Welded, dark red, vesicular, sandine?-rich rhyolite agglutinate, to open-framework rhyolite breccia | Hematite staining of clay minerals (smectite?), and silicification |