Table T3. Lithologic units and subunits, Site 1196.
| Unit | Subunit | Hole 1196A | Hole 1196B | Description | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Core | Depth (mbsf) | Core | Depth (mbsf) | |||||||
|
Top
|
Base
|
Top
|
Base
|
Top
|
Base
|
Top
|
Base
|
|||
| I | IA | 1R-1, 0 | 13R-2, 100 | 000.0 | 117.2 | 1R-1, 0 | 17Z-1, 0 | 000.0 | 122.9 | Dolomitic floatstone/rudstone. Grainstone matrix. Distinctive constituents are centimeter-sized rhodoliths. Dolomitization is not pervasive. |
| IB | 13R-2, 100 | 14R-2, 20 | 117.2 | 125.9 | 17Z-1, 0 | 20Z-1, 20 | 122.9 | 130.5 | Dolomitic floatstone. Constituents include larger benthic foraminifers (seen as molds) and branching red algal debris. | |
| IC | 14R-2, 20 | 18R-1, 0 | 125.9 | 162.8 | 20Z-1, 20 | 24Z-1, 0 | 130.5 | 145.0 | Skeletal rudstone/boundstone with colonial corals alternating with dolomitic floatstone with molds of benthic foraminifers. | |
| ID | 18R-1, 0 | 20R-1, 27 | 162.8 | 182.2 | 24Z-1, 0 | 33Z-1, 0 | 145.0 | 184.9 | Dolomitic floatstone. Predominant constituents include larger benthic foraminifers, which are commonly dissolved, and branching red algal fragments. Rare coral present. | |
| II | IIA | 20R-1, 27 | 35R-1, 40 | 182.2 | 335.9 | 33Z-1, 0 | ? | 184.9 | Skeletal floatstone. Predominant constituents are porcellaneous benthic foraminifers and centimeter-sized mollusk fragments. Thin, well-sorted grainstone intervals occur at 232 and 317 mbsf. Nannofossil age: 13.6-18.2 Ma at 218 and at 316 mbsf. Foraminifer age: 13.3-15.2 Ma throughout the unit. | |
| IIB | 36R-1, 0 | 37R-1, 30 | 335.9 | 345.8 | Skeletal rudstone/boundstone. Reefal facies containing hermatypic corals, red algae, and mollusk fragments. | |||||
| III | IIIA | 37R-1, 30 | 38R-1, 20 | 345.8 | 355.3 | Dolomitic rudstone. Reefal facies showing ghosts of rhodoids, corals, and mollusk fragments. | ||||
| 39R | 42R | 355.3 | 412.7 | Insignificant recovery. | ||||||
| IIIB | 44R-1, 0 | 50R-1, 0 | 412.7 | 470.4 | Sucrosic dolostone. Rare relicts of centimeter-sized rhodoids are preserved. Coarsely crystalline. | |||||
| IIIC | 50R-1, 0 | 57R-1, 0 | 470.4 | 537.7 | Variegated dolostone. Ghosts of rhodoliths visible locally. Moldic porosity after benthic foraminifers. Contains several brownish layers interpreted as exposure surfaces. Evidence for fracturing. Coarsely crystalline. | |||||
| IIID | 57R-1, 0 | 65R-2, 85 | 537.7 | 617.1 | Dolostone with molds. Molds after benthic foraminifers are typical. Rare rhodoliths, red algae, and mollusk fragments. Two thin intervals of dolomitic skeletal grainstone with abundant benthic foraminifers occur in Core 63R. | |||||
| IV | 65R-2, 85 | 70R-1, 0 | 617.1 | 662.6 | Mixed dolomitic rocks. Various facies containing noncarbonate grains (quartz, glauconite) and forming meter-scale sequences separated by exposure surfaces. | |||||
| V | 70R-1, 0 | ? | 662.6 | ? | Siliciclastic substrate. Dark sandstone, claystone, and phosphatic sands of latest Oligocene age (24.2-24.6 Ma). | |||||
Notes: Hole 1196B end of core at 265.3 mbsf. ? = not defined.