Ge104: Introduction to Geobiology

Transcription

1 Ge104: Introduction to Geobiology Professor: Woody Fischer Office: 107 N. Mudd [x6790] Office hours: by appt. TA: Jena Johnson Office: 102 N. Mudd Office hours: TBD Meeting Time: Lecture: TT 7-8:30pm 267 Arms No Lab. No Section. Website: Look here for lecture slides and exercise materials.

2 Performance assessment: Quizzes 05% Writing (5x) 40% Midterm exam 20% Final exam 35%

3 xams: There are two exams, midterm and final. Both are take home and closed book. The midterm will be 1 hour and cumulative. The final will be 3 hours and cumulative, but weighted to topics covered in the second half of the course. Important exam dates: midterm Nov. 1, final Dec. 14. Note that the final date may change depending on how we arrange the schedule at the end of the course to accommodate students attending the Fall AGU meeting. Quizzes: There will be two short quizzes, administered in class, to test your understanding of the geological timescale [ timescale/ ]. Tue 10/9, and Thu 11/8.

4 Writing (News & Views): This is an opportunity to practice and hone your critical reading and writing skills in the context of learning about geobiology. very two weeks you will write a short perspective piece on a recently published study broadly related to the geobiology subdiscipline. The goal is to emulate the style, feeling, and intent of a Nature "News & Views" article. These articles are limited to 1000 words (excluding figure caption and references). They should have more than 5 but less than 12 references, and one original color figure that helps explain the interesting aspects of the study being discussed (e.g. - problem, data, methods, results, interpretation). Make it visually appealing. Choose a paper that (a) was published in the past month, (b) is on a topic of interest to you and broadly related to geobiology, and (c) makes a breakthrough, however small, in understanding an important geobiological process or event. You will need to read through a number of papers to find one that is suitable. Attached in the appendix is a list of some common journals for geobiology research. Try browsing the most recent issues or articles in press. And just because a paper already has a published perspective piece (either in Nature or Science Magazine) you can still use it for your N&V, particularly if you disagree with the perspective or see the importance of the study differently. Your N&V are due at the beginning of class on the due date. Please compile your articles into pdf format and embed your figure and caption in the text, and submit them electronically via to Sebastian and I. At the beginning of class on the day N&Vs are due, you will be expected to give a very brief (3 minute) review of your paper to the class and field questions arising from quick discussion. N&V due dates: Oct. 9, Oct. 23, Nov. 6, Nov. 20, Dec. 4 [date may change due to AGU].

5 Some questions you can ask to get started: What problem is this paper addressing, and why is it important? What approach did the authors bring to bear on this problem (e.g., new methods, inverse modeling, statistical reanalysis, new observations, new theory)? Can you reconstruct the logic of the argument? How were the data interpreted? How could the data be interpreted? What did the study do right? What did it do wrong? What is the next step?

6 Collaboration Policy: You are expected to abide by the Caltech honor code. Present your own work. You can consult with classmates for thoughts on your News & Views exercises, but not on quizzes or exams. When researching and writing your News & Views papers, cite only references from the primary published literature. Late Work Policy: Students are responsible for handing in work on time. Worked turned in one day late will be marked down by 25%. Work turned in thereafter (and until the final day of class) will be marked down by 50%. No late work will be accepted after the final day of class.

7 The history of the arth is inseparable from the history of life on arth Goal: decipher, understand, and appreciate the interplay between life and environments Fundamental Duality: process and history

8 The greatest contribution of arth scientists to Science is the discovery of time.

9 We are fortunate that arth has recorded its history How do we know time?

10 AG (Ma) MAGNTIC POLARITY HIST. ANOM. CHRON. 1 C1 2 2A 3 3A 4 4A 5 5A 5B 5C 5D 5 6 6A 6B 6C C2 C2A C3 C3A C4 C4A C5 C5A C5B C5C C5D C5 C6 C6A C6B C6C 7 C7 7A C7A 8 C C9 C10 C11 C12 C13 C15 C16 C17 C18 C19 C20 C21 C22 C23 C24 C25 C26 C27 C28 C29 30 C30 CNOZOIC PRIOD Terreneuvian QUATR- NARY TRTIARY PALOGN NOGN POCH HOLOCN PLISTOCN PLIOCN MIOCN OLIGOCN OCN PALOCN L M L L M L M AG CALABRIAN GLASIAN PIACNZIAN ZANCLAN MSSINIAN TORTONIAN SRRAVALLIAN LANGHIAN BURDIGALIAN AQUITANIAN CHATTIAN RUPLIAN PRIABONIAN BARTONIAN LUTTIAN YPRSIAN THANTIAN SLANDIAN DANIAN 2009 GOLOGIC TIM SCAL PICKS (Ma) AG (Ma) MAGNTIC POLARITY HIST. ANOM. MSOZOIC CHRON. 30 C30 31 C31 32 C32 33 C33 34 C34 M0r M1 M3 M5 M10 M12 M14 M16 M18 M20 M22 M25 M29 RAPID POLARITY CHANGS PRIOD POCH TRIASSIC JURASSIC CRTACOUS LAT ARLY LAT MIDDL ARLY LAT MIDDL ARLY AG MAASTRICHTIAN CAMPANIAN SANTONIAN CONIACIAN TURONIAN CNOMANIAN ALBIAN APTIAN BARRMIAN HAUTRIVIAN VALANGINIAN BRRIASIAN TITHONIAN KIMMRIDGIAN OXFORDIAN CALLOVIAN BATHONIAN BAJOCIAN AALNIAN TOARCIAN PLINSBACHIAN SINMURIAN HTTANGIAN RHATIAN NORIAN CARNIAN LADINIAN ANISIAN OLNKIAN INDUAN PICKS (Ma) AG (Ma) PALOZOIC PRIOD PRMIAN CAMBRIAN* ORDOVICIAN SILURIAN DVONIAN CARBONIFROUS POCH L M PNNSYL- VANIAN MISSIS- SIPPIAN L M L M L M Series 3 Series 2 Furongian Walker, J.D., and Geissman, J.W., compilers, 2009, Geologic Time Scale: Geological Society of America, doi: /2009.CTS004R2C The Geological Society of America. AG CHANGHSINGIAN WUCHIAPINGIAN CAPITANIAN WORDIAN ROADIAN KUNGURIAN ARTINSKIAN SAKMARIAN ASSLIAN GZLIAN KASIMOVIAN MOSCOVIAN BASHKIRIAN SRPUKHOVIAN VISAN TOURNAISIAN FAMNNIAN FRASNIAN GIVTIAN IFLIAN MSIAN PRAGHIAN LOCKHOVIAN PRIDOLIAN LUDFORDIAN GORSTIAN HOMRIAN SHINWOODIAN TLYCHIAN ARONIAN RHUDDANIAN HIRNANTIAN KATIAN SANDBIAN DARRIWILIAN DAPINGIAN FLOIAN TRMADOCIAN STAG 10 STAG 9 PAIBIAN GUZHANGIAN DRUMIAN STAG 5 STAG 4 STAG 3 STAG 2 FORTUNIAN PICKS (Ma) AG (Ma) PRCAMBRIAN ON PROTROZOIC ARCHAN *International ages have not been fully established. These are current names as reported by the International Commission on Stratigraphy. RA NOPRO- TROZOIC MSOPRO- TROZOIC PALOPRO- TROZOIC NOARCHAN MSO- ARCHAN PALO- ARCHAN OARCHAN PRIOD DIACARAN CRYOGNIAN TONIAN STNIAN CTASIAN CALYMMIAN STATHRIAN OROSIRIAN RHYACIAN SIDRIAN Sources for nomenclature and ages are primarily from Gradstein, F., Ogg, J., Smith, A., et al., 2004, A Geologic Time Scale 2004: Cambridge University Press, 589 p. Modifications to the Triassic after: Furin, S., Preto, N., Rigo, M., Roghi, G., Gianolla, P., Crowley, J.L., and Bowring, S.A., 2006, High-precision U-Pb zircon age from the Triassic of Italy: Implications for the Triassic time scale and the Carnian origin of calcareous nannoplankton and dinosaurs: Geology, v. 34, p , doi: /G22967A.1; and Kent, D.V., and Olsen, P.., HADAN BDY. AGS (Ma)

11 Nicholas Steno ( ) Steno s Laws of Stratigraphy: Law of Superposition Law of Original Horizontality Law of Lateral Continuity...then he converted to Catholicism and became a priest.

12 Relative timescales Field relationships F D C J I H G D C J I H F D B A B A C B What s the sequence of events in this cross-section?

13 Relative timescales Relative timescales can be constructed locally from rocks in contact with one another, but how can we construct relative timescales across large distances (e.g. Colorado and South China)? Find a phenomenon global in scope and preservable in rocks that changes systematic through time!

14 Relative timescales Biostratigraphy William Smith (1815) He made the first geological map......then he died in a debtor s prison.

15 Relative timescales Biostratigraphy Taxa useful for biostratigraphy widespread environmentally and geographically limited time span easily fossilized easily identified Time Limitations Facies/ecology Paleogeography/Provincialism FAD and LAD evolution volution

16 Absolute timescales Radiometric

17 Absolute timescales Radiometric 2/+.3'41,%'(. 5678"9%"(!"#$%&'( )%*+,-. (",#/+,(.0%1+,%'

18 Absolute timescales Radiometric 543+/-1 Ma

19 Absolute timescales Radiometric

20 Relative timescales Magnetostratigraphy AG (Ma) MAGNTIC POLARITY HIST. ANOM. CHRON. 1 C1 2 C2 2A C2A 3 C3 3A C3A 4 4A 5 5A 5B 5C 5D C4 C4A C5 C5A C5B C5C C5D 5 C5 6 C6 6A C6A 6B C6B 6C C6C 7 C7 7A C7A 8 C8 9 C9 10 C C11 C12 C13 C15 C16 C17 C18 19 C C20 C21 C22 C23 C24 C25 C26 27 C C28 C29 30 C30 CNOZOIC PRIOD Terreneuvian QUATR- NARY TRTIARY PALOGN NOGN POCH HOLOCN PLISTOCN PLIOCN MIOCN OLIGOCN OCN PALOCN L M L L M L M AG CALABRIAN GLASIAN PIACNZIAN ZANCLAN MSSINIAN TORTONIAN SRRAVALLIAN LANGHIAN BURDIGALIAN AQUITANIAN CHATTIAN RUPLIAN PRIABONIAN BARTONIAN LUTTIAN YPRSIAN THANTIAN SLANDIAN DANIAN 2009 GOLOGIC TIM SCAL PICKS (Ma) AG (Ma) MAGNTIC POLARITY HIST. ANOM. MSOZOIC CHRON. 30 C30 31 C M0r M1 M3 M5 M10 M12 M14 M16 M18 M20 M22 M25 M29 C32 C33 C34 RAPID POLARITY CHANGS PRIOD POCH TRIASSIC JURASSIC CRTACOUS LAT ARLY LAT MIDDL ARLY LAT MIDDL ARLY AG MAASTRICHTIAN CAMPANIAN SANTONIAN CONIACIAN TURONIAN CNOMANIAN ALBIAN APTIAN BARRMIAN HAUTRIVIAN VALANGINIAN BRRIASIAN TITHONIAN KIMMRIDGIAN OXFORDIAN CALLOVIAN BATHONIAN BAJOCIAN AALNIAN TOARCIAN PLINSBACHIAN SINMURIAN HTTANGIAN RHATIAN NORIAN CARNIAN LADINIAN ANISIAN OLNKIAN INDUAN PICKS (Ma) AG (Ma) PALOZOIC PRIOD POCH PRMIAN CAMBRIAN* ORDOVICIAN SILURIAN DVONIAN CARBONIFROUS L M PNNSYL- VANIAN MISSIS- SIPPIAN L M L M L M Series 3 Series 2 Furongian Walker, J.D., and Geissman, J.W., compilers, 2009, Geologic Time Scale: Geological Society of America, doi: /2009.CTS004R2C The Geological Society of America. AG CHANGHSINGIAN WUCHIAPINGIAN CAPITANIAN WORDIAN ROADIAN KUNGURIAN ARTINSKIAN SAKMARIAN ASSLIAN GZLIAN KASIMOVIAN MOSCOVIAN BASHKIRIAN SRPUKHOVIAN VISAN TOURNAISIAN FAMNNIAN FRASNIAN GIVTIAN IFLIAN MSIAN PRAGHIAN LOCKHOVIAN PRIDOLIAN LUDFORDIAN GORSTIAN HOMRIAN SHINWOODIAN TLYCHIAN ARONIAN RHUDDANIAN HIRNANTIAN KATIAN SANDBIAN DARRIWILIAN DAPINGIAN FLOIAN TRMADOCIAN STAG 10 STAG 9 PAIBIAN GUZHANGIAN DRUMIAN STAG 5 STAG 4 STAG 3 STAG 2 FORTUNIAN PICKS (Ma) AG (Ma) PRCAMBRIAN ON PROTROZOIC ARCHAN *International ages have not been fully established. These are current names as reported by the International Commission on Stratigraphy. RA NOPRO- TROZOIC MSOPRO- TROZOIC PALOPRO- TROZOIC NOARCHAN MSO- ARCHAN PALO- ARCHAN OARCHAN PRIOD DIACARAN CRYOGNIAN TONIAN STNIAN CTASIAN CALYMMIAN STATHRIAN OROSIRIAN RHYACIAN SIDRIAN Sources for nomenclature and ages are primarily from Gradstein, F., Ogg, J., Smith, A., et al., 2004, A Geologic Time Scale 2004: Cambridge University Press, 589 p. Modifications to the Triassic after: Furin, S., Preto, N., Rigo, M., Roghi, G., Gianolla, P., Crowley, J.L., and Bowring, S.A., 2006, High-precision U-Pb zircon age from the Triassic of Italy: Implications for the Triassic time scale and the Carnian origin of calcareous nannoplankton and dinosaurs: Geology, v. 34, p , doi: /G22967A.1; and Kent, D.V., and Olsen, P.., HADAN BDY. AGS (Ma)

21 Relative timescales vent stratigraphy xamples: Volcanic eruption Tsunami Bollide impact

22 Relative timescales Chemostratigraphy D. DePaulo

23 !"#$% Relative timescales Chemostratigraphy &'(#)#*#$ &+,$-. Shuram C isotope excursion

24 10 5 Neoproterozoic Palaeozoic Mesozoic Cenozoic Magnitude ( ) Shuram 15 Rank order Figure 1 Historical variability of carbon isotopic composition of sedimentary rocks. Rank order of carbon isotope excursions greater than 2 over the past 1,000 Myr is shown in terms of sign and magnitude. Negative excursions are common in the Neoproterozoic stratigraphic record. The S is the largest of these; such a distribution of isotope excursions through time provides clear evidence for large-scale change in the operation of the global carbon cycle over geologic history. Data from ref. 18.

25 Time (Ma) Oman (composite) Masirah bay Khufai Shuram Buah Ar a Hadash Fiq 13 C ( ) Gaskiers Ingta S heepbed Gametrail Blueflower Risky Stelfox Canada? C N uccaleena Brachina A BC Bunyeroo Wonok a Rawnsle y Bonney Adelaide rift complex 586 ± 30 1 Acraman ejecta Marinoan Glacial C C. Wood Stirling Johnnie Noonday Death valley Wildrose 580 ± 7 Ma Correlated incision age on the Brown s Hole Fm 2 Bänninger (2003) C Dolostones Nama Tsumeb Unconformities Ghaub Namibia ± 1.2Ma 3 Siliciclastics Limestones ± 1Ma C Dengying D C B Yangtze platform South China A Nantuo diacaran fauna Shelly fossil Marinoan glacials C 500 m ± 0. 7Ma ± 0. 6Ma 5 Fig. 6 The d 13 C and strontium isotope composite profile from Oman, plotted against time, shows a major negative excursion and long recovery in the time period c Ma. The Oman section is compared with other successions plotted on a thickness scale:

26 Relative timescales Phylogeny Rokas & Carroll 2006

27 How accurate is comparative biology alone? birth rate death rate Number of species

28 An example from whales (a) (b) (c)

29 Cetacean phylogeny from comparative molecular biology Time (myr)

30 F 3. (Continued) Time (myr)

31

32

33

34 F 3. (Continued) Time (myr)

35 From Steeman et al. (2009) (i.e. - molecules) From PaleoBiology database (i.e. - fossil record) A time of oceans restructuring

36 From Steeman et al. (2009) (i.e. - molecules) From PaleoBiology database (i.e. - fossil record) A time of oceans restructuring

37 Timescale Quiz next Tuesday Know the following intervals: Hadean (4.55Ga Ga) Archean (3.85Ga Ma) Proterozoic (2500Ma - 542Ma) Paleoproterozoic (2500Ma Ma) Mesoproterozoic (1600Ma Ma) Neoproterozoic (1000Ma - 542Ma) diacaran (635Ma - 542Ma) AG (Ma) PRCAMBRIAN ON PROTROZOIC ARCHAN RA NOPRO- TROZOIC MSOPRO- TROZOIC PALOPRO- TROZOIC NOARCHAN MSO- ARCHAN PALO- ARCHAN PRIOD DIACARAN CRYOGNIAN TONIAN STNIAN CTASIAN CALYMMIAN STATHRIAN OROSIRIAN RHYACIAN SIDRIAN BDY. AGS (Ma) on ra Period 3750 HADAN OARCHAN