Geochemistry Applied to Paleontology
Objectives
When studying the ancient environments the paleontology can benefit of the data from isotope geology and from the geochemistry. The information about the faunal associations and the morphological characteristics of the specimen can be complemented with information about their geochemical details allowing the development of more accurate paleoenvironmental reconstructions. Several examples can be cited such as: (i) calculation of the sea water paleotemperatures from marine fossils using the 18O/16O ratios of the exoskeletons; (ii) determination of paleoceanographic conditions through the determination of εNd in sediments and fossils; (iii) evaluate the oxygenation of the water column in a marine environment from the rare-earth concentrations of fossils and sediments.
This course intends to provide a view of the main geochemical and isotopic tools (radiochronology excluded), with applications in paleontology.
General characterization
Code
10937
Credits
6.0
Responsible teacher
Paulo Alexandre Rodrigues Roque Legoinha
Hours
Weekly - Available soon
Total - 51
Teaching language
Português
Prerequisites
Available soon
Bibliography
• Leng, M.J., Barker, P.A. (2006). A review of the oxygen isotope composition of lacustrine diatom silica for palaeoclimate reconstruction, Earth-Science Reviews, 75, 1-4, pp. 5-27.
• Swart, P.K. (1983). Carbon and oxygen isotope fractionation in scleractinian corals: a review Earth-Science Reviews, 19, 1, pp 51-80.
• Jaffres, J., Shields, G.A., Wallmann, K. (2007). The oxygen isotope evolution of seawater: A critical review of a long-standing controversy and an improved geological water cycle model for the past 3.4 billion years, Earth-Science Reviews, 83, 1-2, pp 83-122.
• Kotelnikova, S. (2002). Microbial production and oxidation of methane in deep subsurface, Earth-Science Reviews, 58, 3-4, pp 367-395.
• Prokoph, A., Shields, G.A., Veizer, J. (2008). Compilation and time-series analysis of a marine carbonate [delta]18O, [delta]13C, 87Sr/86Sr and [delta]34S database through Earth history, Earth-Science Reviews, 87, 3-4, pp 113-133.
Teaching method
The course will be supported by lectures in which the main theoretical concepts will be taught and on theoretical-practical applications of the concepts. Each module will have a set of exercises that will comprise the different possibilities of applications for the systems under consideration to the paleontological problems.
Evaluation method
The ranking will result from an exam (theoretical-practical) and a monograph each with a weighting coefficient of 50%.
Subject matter
1) Introduction: the chemical elements
a)Element abundance in the Universe
b)The chemical composition of the Earth’s crust
c)The geochemical classification of the elements
2)Isotopes
a)Stable isotopes and radiogenic isotopes
b)Characteristics of the stable isotope systems with geological interest
c)Mechanisms of fractionation of the stable isotopes
3)Isotopic systems with interest to the Paleontology
a)Oxygen and Carbon
i)Characteristics and properties
ii)Fractionation equations
iii)Paleoenvironmental information: paleotemperature, paleohydrology and paleovegetation
4)The rare-earth elements
a)Chemical properties
b)Mechanisms of fractionation in surficial environments
c)Application in paleoenvironmental studies.
5)Neodymium isotopes: paleoceanographic applications
6)The geochemistry and the Stratigraphy: general concepts and applications
7)Geochemical changes during diagenesis and metamorphism.