Table T11. Biostratigraphic datums used to calculate sedimentation rates, Hole 1261A.
Core, section, interval (cm)
Depth
(mbsf)
Datum type
Taxon
Nannofossil
zone
Foraminifer
zone
Age
(Ma)
Epoch
Minimum
Maximum
207-1261A-







1R-CC, 12–17 3.85 4.61 Base Emiliania huxleyi NN21
0.26 late Pleistocene
2R-CC, 12–17 3.85 4.61 Top Pseudoemiliania lacunosa NN19
0.42 Pleistocene
3R-CC, 18–23 4.61 14.77 Top Sphenolithus sp. NN16
3.66 early Pliocene
3R-CC, 18–23 14.77 72.91 Base Globorotalia truncatulinoides*
PL1 1.92 late Pliocene and Pleistocene
5R-CC, 8–13 72.91 139.50 Top Globorotalia margaritae*
PL2 3.58 early Pliocene
5R-CC, 8–13 72.91 139.50 Top Reticulofenestra pseudoumbilicus NN13–15
3.8 early Pliocene
7R-1, 50–54 237.40 238.90 Base Sphaeroidinella dehiscens
PL2 5.54 early Pliocene
8R-CC, 0–5 246.03 255.72 Top Discoaster quinqueramus NN11
5.54 late Miocene
9R-CC, 21–28 264.74 274.03 Base Nicklithus amplificus NN11
6 late Miocene
20R-CC, 11–16 362.15 371.64 Top Chiasmolithus grandis NP17
37.1 middle Eocene
20R-5, 116–119 369.26 369.30 Base Globorotalia plesiotumida*
M13b 8.58 late Miocene
20R-5, 120–122 369.26 369.30 Top Acarinina and Morozovella spp.*
P14 37.5-38.5 middle Eocene
21R-2, 84–86 371.64 374.12 Top Orbulinoides beckmanni
P13 40.1 middle Eocene
20R-CC, 11–16 371.64 375.50 Base Dictyococcites bisectus NP17
38.5 middle Eocene
21R-CC, 23–29 371.64 375.50 Top Chiasmolithus solitus NP16
40.4 middle Eocene
27R-CC, 0–6 425.53 433.38 Top Chiasmolithus gigas NP15
44 middle Eocene
27R-CC, 0–6 433.38 448.94 Base Chiasmolithus gigas NP15
46.1 middle Eocene
31R-1, 56–58 468.16 487.14 Base Morozovella aragonensis*
P7 52.3 early Eocene
32R-CC, 19–24 468.16 487.14 Top Morozovella velascoensis group
P5 54.7 late Paleocene
34R-CC, 0–5 502.29 513.30 Base Discoaster multiradiatus NP9
56.2 late Paleocene
37R-7, 52–55 534.82 535.02 Base Praemurica uncinata
P2 61.2 early Paleocene
38R-CC, 0–5 535.00 535.26 Top Abathomphalus mayaroensis
KS31 65 Maastrichtian
38R-CC, 0–5 535.00 549.58 Base Micula murus CC26/26
66.2 late Maastrichtian
37R-CC, 0–3 535.02 535.31 Base Chiasmolithus danicus NP3
63.8 early Paleocene
37R-CC, 24–29 535.26 535.31
Approximate K/T boundary (nannofossils)

65 K/T boundary
39R-CC, 16–22 549.58 562.21 Base Globotruncana aegyptiaca*
KS29–31 73.8 late Campanian–Maastrichtian
40R-6, 55–57 549.58 562.21 Top Uniplanarius trifidum CC23
76 late Campanian
41R-CC, 21–22 573.69 583.04 Base Micula decussata CC14
87.2 late Coniacian
42R-3, 106–108 577.33 579.32 Base Contusotruncana fornicata
KS24-23 88 Coniacian
43R-CC, 12–17 590.10 600.49 Base Marthasterites furcatus CC13
89.3 early Coniacian
44R-6, 65–70 600.49 608.11 Base Eiffellithus eximius CC12
91 late Turonian
45R-CC, 5–7 608.11 619.06 Base Eprolithus eptapetalus CC11
93.2 early Turonian
48R-CC, 11–15 630.17 639.93 Top Rotalipora spp.
KS19 94 Cenomanian
48R-CC, 11–15 630.17 639.93 Top Axopodorhabdus albianus CC10
94 late Cenomanian
50R-3, 0–2 653.20
Base Eiffellithus turriseiffelii NC10a
101.7 late Albian

Notes: The minimum and maximum depths represent uncertainty in the depth range calculated based on the distance to the relevant subjacent or superjacent sample examined. See "Biostratigraphy". * = datum probably does not reflect a true range termination because of either coring gaps or preservational problems. K/T = Cretaceous/Tertiary.