1. Quaternary Environments Marine Sediments and Corals

2. Marine Environments  Cover more than 70% of the Earth’s surface  Between 6-11 billion metric tons of sediment accumulate in the ocean basins annually

3. Definitions Planktic – Passively floating organisms living near the surface (0-200m depth) Planktic – Passively floating organisms living near the surface (0-200m depth) Benthic – Bottom-dwelling organisms Benthic – Bottom-dwelling organisms Test – Protective covering Test – Protective covering

4. CLIMAP  The CLIMAP Research Group  Climate: Long-range Investigation, Mapping, and prediction (CLIMAP)  SST and Ocean Surface Conditions  From 635 ocean sediment cores  Data from faunal counts of diatoms, planktonic foraminifera, coccoliths, and radiolaria  Stratigraphy - percent fine, coarse, total carbonate, 18 O and 13 C  Geochemistry - percent opal, quartz, and organic carbon

5. SPECMAP  Spectral Mapping Project  Determining the spectral characteristics of ocean sediment-based paleoclimatic records  Establishing a basic timeframe for past climatic events  Climate times series of the past 400,000 years  Based on 17 sediment cores from the Atlantic Ocean.  Quantitative data on planktonic species and assemblages which reflect conditions in the surface waters of the Atlantic Ocean  18 O, 13 C difference (planktic and benthic), and Cd/Ca.

6. Sedimentation in the Ocean

7. Problems With Marine Sediments  Selective dissolution of thin-walled specimens  Transportation by ocean currents  Removal of easily transported species  Introduction of exotics  These problems may make some ocean floor sediments unsuitable for paleoclimatic reconstructions

8. Regions Usable for Foram Studies

9. Important Organisms  Foraminifera - Zooplankton  Coccolithophores (coccoliths) – Unicellular algae  Dinoflagellate – Organic walled  Radiolarians – Siliceous zooplankton  Silicoflagallates – Siliceous  Diatoms – Siliceous algae

10. Foraminifera – Neogloboquadrina pachyderma from the North Atlantic Foraminifera – Globigerina bulloides from the Labrador Sea

11. CoccolithDinoflagellate Centric DiatomPennate Diatom

13. Paleoclimatic Inferences  Oxygen isotopic composition of CaCO 3 in foram tests  Quantitative interpretations of species assemblages and their spatial variations through time  Morphological variations in particular species resulting from environmental factors

16. Benthic 18 O record for equatorial Atlantic for the past 3.2 Mya

17. SST Reconstructions for 18,000 yrs BP

22. Coral Records of Past Climate  Reef-Building Massive Corals that have a symbiotic relationship with algae  The algae produce carbohydrates through photosynthesis and are therefore dependent upon water depth, turbidity, and cloudiness  Sectioned and x-rayed  High and low density bands can be distinguished with high-density bands relating to high SST

23. http://www.noaanews.noaa.gov/magazine/stories/mag95.htm Drilling corals for paleoclimatic reconstruction.

25. http://www-ocean.tamu.edu/Quarterdeck/QD6.2/giese.html Growth bands in Coral. Arrows indicate "stress bands" revealed in an x-ray of coral skeletal material caused by cold, unfavorable temperatures.

26. Benefits of Coral Analysis  Tropical records that fill gaps left by other marine paleorecords  Annual resolution  Dating is checked with 230 Th  Possible extent back to 130,000 years BP

27. Problems with Coral Analysis  Few records that extend past one century  Real extreme events may go unrecorded do to death of the coral colony for some period of time

28. Long Coral Based Records of Past Climate