Open Earth Systems: An Earth Science Course For Maryland Teacher Professional Development

1. Open Earth Systems: An Earth Science Course For Maryland Teacher Professional Development EARTH HISTORY AND THE FOSSIL RECORD DAY 1 - Weds. July 9 AM Instruction: Solar System Origin, Early Earth & Habitability AM Activity: Dating the Earth PM Instruction: Major Events in Earth History PM Activity: Exploring Geologic Time DAY 2 - Thurs. July 10 AM Instruction: Climates of the Past AM Activity: Weathering, Erosion and Soils PM Instruction: The Fossil Record of Life PM Activity: Fossil Identification LINDA HINNOV, Instructor

2. OUTLINE Paleoclimate archives and proxies Icehouse-Greenhouse oscillations Inventory of Earth’s major icehouses and greenhouses ICEHOUSE FOCUS: Late Proterozoic snowballs GREENHOUSE FOCUS - Early Cenozoic hyperthermia ICEHOUSE FOCUS – Last Glacial Maximum

3. archives Paleoclimate archives and proxies Earth materials that contain a signature of paleoclimatic conditions proxies Isotopes deuterium, oxygen Plants stomata, leaf margins, tree rings Gas in ice CO2, CH4in gas bubbles Minerals evaporites, glendonites, coal, clays Marine Organisms Faunal assemblages Other Proxies Geomorphology, sedimentary facies

4. Icehouse-Greenhouse oscillations Glacial Non-glacial Pan-glacial

5. Inventory of Earth’s major icehouses and greenhouses PRECAMBRIAN: GREENHOUSE: Archean-Proterozoic ICEHOUSE: ArcheanWitwatersrand glaciation ICEHOUSE: Early Proterozoic Huronian glaciation * ICEHOUSE: Late Proterozoic “snowball earths” PHANEROZOIC: GREENHOUSE: Early Paleozoic greenhouse(s) ICEHOUSE: Late Ordovician glaciation ICEHOUSE: Permo-Carboniferous glaciations GREENHOUSE: Late Permian - Triassic greenhouse and hot spikes ICEHOUSE: Jurassic-Cretaceous “cool”phases GREENHOUSE: Jurassic-Cretaceous greenhouses and OAEs * GREENHOUSE: Early Cenozoic hyperthermia (the PETM) ICEHOUSE: Late Cenozoic glaciation GREENHOUSE: Pliocene Warm interval • ICEHOUSE: Pleistocene – Last Glacial Maximum

6. * * Atmospheric CO2 Greenhouses? Kastings, 1987

7. Atmospheric CO2

8. Earth’s great icehouses http://www.snowballearth.org

9. ICEHOUSE FOCUS: Late Proterozoic snowballs http://www.snowballearth.org

10. The tillite-bearing Ghaub Formation has been mapped for >600 km along the outer arc of the Otavi fold belt. Marinoan Snowball 635 Ma http://www.snowballearth.org

11. TODAY: Supraglacial/Ice-margin Environments on top of or along the margin of the glacier A dirty-ice zone at a glacier's leading edge. Debris carried in the ice melts out and piles up at the glacier's edge. Till-like mixtures of material with a wide range of particle sizes, called "diamicton", are interspersed with waterlain sediments from lakes and streams. This photo shows a moraine forming at the edge of a glacier in eastern Canada. http://www.isgs.uiuc.edu/research/glacial-geology/

12. Marinoan Snowball 635 Ma http://www.snowballearth.org

13. TODAY: ProglacialEnvironments Sediments of the proglacial environment include materials sorted by water or wind: river sediment (outwash), lake deposits (rhythmites), and windblown sand and silt (loess). in front of the glacier Proglacial lake at the southern margin of Flaajokull, Iceland. Proglacial lake sediment in a pit near Chicago. http://www.geology.wisc.edu/~qlab/iceland/iceland2000.html http://www.isgs.uiuc.edu/research/glacial-geology/

14. Marinoan Snowball 635 Ma - post glacial cap carbonate, Namibia http://www.snowballearth.org

15. Phanerozoic temperatures based on the marine oxygen isotope record * Major greenhouses * * * * * CE=common era R. Rohde http://commons.wikimedia.org/wiki/File:All_palaeotemps.png

16. Phanerozoic oxygen isotope record (other glacial deposits) (paleolatitude of ice raft debris) Veizer et al., 2000

17. GREENHOUSE FOCUS - Early Cenozoic hyperthermia PETM= Paleocene/Eocene Thermal Maximum • The end of the Paleocene (55.5/54.8 Ma) was marked by the Paleocene-Eocene Thermal Maximum (PETM): • rise in atmospheric CO2 and global temp. • Sea surface temperatures rose ~8ºC. • altered ocean/ atmosphere circulation • extinction of 30-40% benthic foraminifera • a major turnover in mammals Sea surface temperatures at the North Pole reached as high as 23ºC (73ºF). Today's mean annual temperature at the N. Pole is around -20ºC (-4ºF). http://www.yale.edu/opa/newsr/06-06-01-03.all.html http://scicom.ucsc.edu/SciNotes/0301/warm/index.html

18. GREENHOUSE FOCUS - Early Cenozoic hyperthermia During the PETM, the Earth remained warm for about 80,000 to 200,000 years. On land, there was a massive turnover of mammals, with primitive mammals that had developed since the end of the Cretaceous suddenly replaced by ancestors of most of the surviving modern mammal groups, all of them in small versions, adapted to Eocene heat. Plant life was characterized by the boreotropical flora, with extensive high-latitudeforests composed of large, fast-growing trees such as Dawn Redwood (Metasequoia) as far north as 80°N. Metasequoiaglyptostroboides http://scicom.ucsc.edu/SciNotes/0301/warm/index.html http://en.wikipedia.org/wiki/Paleocene-Eocene_Thermal_Maximum

19. GREENHOUSE FOCUS - Early Cenozoic hyperthermia Summary of environmental records and a 3-phase model of Earth Systems evolution through the (PETM). E. Patterns of biotic change: • tropical dinoflagellates (Apectodinium) at N. Pole • small-bodied mammals • extinction of benthic foraminifera A. Terrestrial paleosol carbonate records from northern Wyoming (dark green) northern Spain (light green), and southern China (olive green). Dashed lines track onset of the PETM event. B. Marine planktonic foraminifera records from the subtropical Pacific (red) and southern Atlantic (blue). Carbon isotope changes during the onset of the PETM (dashed lines) occurred as a series of abrupt (~1 Kyr) steps. C. Difference of the averaged carbon isotope curves for the 3 terrestrial and 2 surface ocean records. Bowen et al., 2006 D. Surface temperature anomaly records for the 2 oceanic sites, with colors as in B.

20. GREENHOUSE FOCUS - Early Cenozoic hyperthermia Proposed cause of the hyperthermia During the Paleocene/Eocene transition, a sharp decrease in the amount of heavy carbon in 55-million-year-old occurred marine fossils. A gas with very low amounts of heavy 13C must have flooded the atmosphere: methane gas has enough light carbon to produce the change. The hypothesis: methane escaped from submarine methane hydrates in cold bottom water under great pressures, plentiful and widely distributed in sediments on the outer edges of continental margins. Methane is estimated to be 21 times as effective as carbon dioxide as a greenhouse gas. The released methane oxidized to carbon dioxide, raising atmospheric carbon dioxide levels to as high as 3,000 ppm, compared with almost 380 ppm today. This carbon dioxide increased the acidity of seawater, accelerating dissolution of calcite shells of microplankton, leaving behind nonsoluble clays. A documented change in colors of the sediment, from bright white carbonate to deep red clays, marks the PETM. Normal deposition of microscopic carbonate foram shells did not resume for at least 50,000 years, and the total recovery time to a "normal state" took ~100,000 years. DEEP SEA CORES RECORD ACIDIFICATION OF OCEAN Demerara Rise offshore Brazil ODP Leg 207 Scientific Party http://www.palmod.uni-bremen.de/FB5//geochron/Robert/RPSpeb.html

21. Pliocene Warm Interval PLIOCENE

22. LAST GLACIAL MAXIMUM 20,000 YEARS AGO Numbers: kiloyears bp

23. LAST GLACIAL MAXIMUM 20,000 YEARS AGO