1. Questions? Discussion? Age Model Exercise I Note: FA = FO and LA = LO throughout investigation!

2. Questions? Discussion? Leg 208 - Oceanographic Setting NW Perspective View Walvis Ridge South Atlantic

3. Questions? Discussion? “Age-Depth_Cenozoic” Worksheet Original

4. Part I. Determine absolute ages for planktonic foraminifera FAs and LAs Example: Row 36 of “Site_1262” Worksheet: LA M. aragonensis

5. Part I. Determine Absolute Ages for FAs and LAs of Planktonic Foraminifera Example: Row 36 of “Site_1262” Worksheet: LA M. aragonensis Table 9 of Berggren et al. (1995): Datum 28... 52.3 Ma

6. Questions? Discussion? “Age-Depth_Cenozoic” Worksheet with PF Datums

7. Example: Row 41 of “Site_1262” Worksheet: PM-NormOnset Part II. Uniquely Identify Magnetochron Reversals and Their Absolute Ages

8. Example: Row 41 of “Site_1262” Worksheet: PM-NormOnset Table 2 of Berggren et al. (1995): Onset of C24n.3n aka C24n 53.347 Ma Note that Table 2 lists only the terminations and onsets of normal magnetochrons!

9. Questions? Discussion? “Age-Depth_Cenozoic” Worksheet with PF and PM Datums

10. Questions? Discussion? Leg 208 - Oceanographic Setting NW Perspective View Walvis Ridge South Atlantic

11. Carbonate Sedimentation Patterns (from Trujillo & Truman, 2005)

12. Carbonate Sedimentation Processes CaCO 3 solubility increases with: –Decreasing Temperature –Increasing Pressure –Increasing  CO 2 Calculated calcite saturation curve Typical carbonate ion concentration Carbonate Compensation Depth (CCD) – <20 wt% CaCO 3 –Modern depth: 3.5-4.5 km (from The Open University)

13. Estimating PaleoCCD from Cores Simplified shelf:basin compensation model Sea Level CCD Site receives less than 20 wt% CaCO 3 Continental Shelf Abyssal Plain Ridge Abyssal Plain

14. Sea Level CCD Continental Shelf Abyssal Plain Ridge Abyssal Plain Site receives greater than 20 wt% CaCO 3 Estimating PaleoCCD from Cores Simplified shelf:basin compensation model

15. Paleodepth Reconstruction Sea Level and CCD display a positive correlation Other related controls include:  CO 2, Ca, and CO 3 2- ion supply from weathering (from Van Andel, 1979)

16. Questions? Discussion? Age Model Exercise I Site 1262 (Deep) Site 1263 (Shallow) (from Leg 208 Initial Reports)

17. Questions? Discussion? Spatiotemporal Variations in Wt% Carbonate in Leg 208 Sites (from Leg 208 Initial Reports)

18. Part III. Biomagnetostratigraphic Constraints on the...

19. Questions? Discussion? Eocene Layer of Mysterious Origin Paleocene-Eocene Thermal Maximum (from Lourens et al., 2005)(from Zachos et al., 2005) Recovery 139.22 mcd Onset 140.12 mcd Onset 117.62 mcd ~118 kyr

20. Questions? Discussion? “Age-Depth_ELMO_PETM” Worksheet

21. Questions? Discussion? Eocene Layer of Mysterious Origin Paleocene-Eocene Thermal Maximum (from Lourens et al., 2005)(from Zachos et al., 2005) Recovery 139.22 mcd Onset 140.12 mcd Onset 117.62 mcd ~118 kyr

22. Questions? Discussion? If one uses the CN linear regression model... Elmo age = 0.0828*mcd+43.389 = 53.128 Ma

23. Questions? Discussion? Eocene Layer of Mysterious Origin Paleocene-Eocene Thermal Maximum (from Lourens et al., 2005)(from Zachos et al., 2005) Recovery 139.22 mcd Onset 140.12 mcd Onset 117.62 mcd ~118 kyr

24. Questions? Discussion? If one uses the CN linear regression model... Elmo age = 0.0828*mcd+43.389 = 53.128 MaPETM age = 0.0828*mcd+43.389 = 54.916 Ma

25. Questions? Discussion? Eocene Layer of Mysterious Origin Paleocene-Eocene Thermal Maximum (from Lourens et al., 2005)(from Zachos et al., 2005) Recovery 139.22 mcd Onset 140.12 mcd Onset 117.62 mcd ~118 kyr

26. Questions? Discussion? If one uses the CN linear regression model... Elmo age = 0.0828*mcd+43.389 = 53.128 MaPETM age = 0.0828*mcd+43.389 = 54.916 Ma Elmo–PETM onset interval = 54.916-53.128+0.118 = 1.906 = 1.91 Myr

27. ElmoPETM ChronC24nC24r Epoch Early Eocene Age Ypresian PFZ P6b P5 CNZ NP11 NP9

29. Mass Accumation Rates (MARs) Linear sedimentation rate (LSR) vs. mass accumulation rate (MAR) MAR calculation: Y something (moles, counts, etc.) * dry bulk density (g/cm 3 ) * LSR (cm/kyr) Resulting MAR units: Y something cm -2 kyr -1 (e.g., 127 g CaCO 3 cm -2 kyr -1 ; 127 benthic foraminifera cm -2 kyr -1 )

30. Questions? Discussion? Age Model Exercise I Site 1262 (Deep) Site 1263 (Shallow) (from Leg 208 Initial Reports)

31. Site 1262 (Deep) Site 1263 (Shallow)

32. Questions? Discussion? “Age-Depth_ELMO_PETM” Worksheet

33. Age Model Round-Up

34. Age Models – Gots, Needs, etc. Getting/giving data: IODP Janus, NGDB, journal archiving/appendices Depths/heights are static, age models evolve Primacy of age models: Interpretations built on rock or sand? Effects of changing sedimentation rates on age models Cyclostratigraphy: Going from space- to time-domain Garbage in, garbage out: Analyzing  18 O for periodicity