Table T2. Summary of lithostratigraphic units, Hole 1276A.
Unit
Age
Core, section, interval (cm)
Depth
(mbsf)
Thickness
(m)
Lithology
(major/minor)
Color
(major/minor)


210-1276A-



1 middle Eocene to early Oligocene
 1W-1, 0 through 8R-5, 113 Top = 753.00-794.13 Base = 864.73 70.6-111.73 Mudstone and claystone Greenish gray, olive green, olive gray, to grayish olive





Grainstone; muddy sandstone and sandy mudstone Olive gray to light olive gray; pale yellowish brown
2 late Paleocene to middle Eocene 8R-5, 113 through 15R-3, 125 864.73-929.25 64.52 Grainstone and calcareous sandstone Very light gray, greenish gray, light brown
Marlstone Reddish brown, grayish red, greenish gray





Claystone and mudstone Olive gray, moderate olive brown, moderate brown
3


early Campanian to late Paleocene


15R-3, 125 through 25R-5, 80


929.25-1028.00


98.75


Claystone and mudstone

 

 Moderate brown, grayish green, light olive gray, greenish black
Grainstone and calcareous sandstone Yellowish gray, light greenish gray, olive gray, light olive gray, white, pale olive, light brown
Marlstone Pale green to light brown
Calcareous siltstone Yellowish gray, light greenish gray, olive gray, light olive
Sandy mudstone Light olive gray, olive gray, moderate brown
4


Turonian to late Santonian


25R-5, 80 through 29R-6, 62


1028.00-1067.24


39.24


Sandy mudstone and muddy sandstone Brown and yellowish brown
Sandstone Brown to light brown
Mudstone/siltstone Light brown/moderate brown
5A


Cenomanian to Turonian


29R-6, 62 through 36R-2, 129


1067.24-1129.80


62.56


Claystone and mudstone/calcareous sandstone Dark greenish gray, greenish gray moderate brown, greenish black, yellowish green, grayish black/light olive gray, medium gray
Marlstone Light olive gray, greenish gray, grayish blue
Black shale Grayish black, dark gray, olive black
Grainstone Light olive gray, medium light gray, greenish gray, yellowish gray
5B


Albian to Cenomanian


36R-2, 129 through 75R-3, 142


1129.80-1502.12


372.32


Claystone, mudstone, and calcareous mudstone/sandstone and siltstone Dark greenish gray, moderate brown, greenish black, olive black, dark gray, olive gray/light olive gray, medium gray
Black shale Grayish black, dark gray, olive black
5C


?late Aptian to Albian


75R-3, 142 through 104R (unrecovered)


Top = 1502.12Base = 1732.12-1736.9


234.78


Claystone and mudstone/sandstone and siltstone Dark greenish gray, moderate brown, greenish black/light olive gray, medium gray
Grainstone Light olive gray, medium light gray
5C1 Albian or younger 87R-6, 72 through 88R-7, 117 1612.72-1623.00 10.3 Diabase sill
5C ?late Aptian to Albian Continuation of 5C (see above) (see above) (see above) Continuation of 5C (see above)
5C2 Albian or younger 99R, entire core through 104R (unrecovered) Top = 1719.40 Base = 1732.12-1736.9 12.72-17.5 Diabase sill
 
Unit
Age
Sedimentation rate
(m/m.y.)
Physical processes
1 middle Eocene to early Oligocene
 ~7, but poorly constrained Hemipelagic deposition (claystone) punctuated by deposition from turbidity currents and debris flows. Postdepositional folding, shearing, and extensional faulting.
2 late Paleocene to middle Eocene ~7 Hemipelagic deposition (claystone) punctuated by deposition from frequent turbidity currents (high proportion of graded beds).
3 early Campanian to late Paleocene ~1-8; lowest in Core 210-1276A-22R
 Hemipelagic deposition (claystone) punctuated by deposition from mud-laden turbidity currents. Condensed interval of sandy mudstone in Core 210-1276A-22R with abundant Zoophycos.
4 Turonian to late Santonian ~2 or less Slow accumulation of thinly interbedded sand and mud, in variable proportions, sufficiently slowly that burrowers completely homogenize the sediment; possible slow reworking of originally downslope-transported material by fluctuating bottom currents to produce coarsening-fining cycles.
5A Cenomanian to Turonian ~2-15.0 Mud-dominated gravity-flow deposits (~80%) alternating with (1) bioturbated hemipelagic mudrocks and (2) periodic slow accumulation of carbon-rich muds from suspension with no bioturbation (due to anoxia).
5B Albian to Cenomanian ~18-100 Hemipelagic bioturbated mudrock (~70%) punctuated by (1) mud-dominated gravity-flow deposits (~10%) and (2) periodic slow accumulation of carbon-rich muds from suspension with no bioturbation (due to anoxia).
5C ?late Aptian to Albian ~22-100 Mud-dominated gravity-flow deposits (~90%) alternating with (1) bioturbated hemipelagic mudrocks and (2) very rare accumulation of carbon-rich muds from suspension with no bioturbation (due to anoxia).
5C1 Albian or younger
Igneous intrusion
5C ?late Aptian to Albian ~22 Continuation of 5C (see above)
5C2 Albian or younger
Igneous intrusion