Geochemistry
Faculty
Hagit Affek
Associate ProfessorRead MoreMy research focuses on global climate change and the use of isotope geochemistry to understand climatic and atmospheric processes. I am interested in the parameters and mechanisms that control paleotemperature proxies; in particuler, my group develops and uses the novel proxy carbonate clumped isotopes. We examine biological parameters that affect clumped isotopes and develop its use in new archive materials; we study the effect of non equilibrium processes on clumped isotopes and oxygen isotopes. We apply clumped isotpes to reconstruct paleotemperature and paleo-rainfall in different time periods during the Cenzoic. I am also interested in the use of isotopes to understand the modern carbon cycle and the effect of the biosphere of atmospheric chemistry.
What is clumped isotopes geochemistry?
Analysis of an isotopic composition is a measurement of the relative abundance of a heavy, rare, isotope within a group of molecules. The term ‘clumped isotopes’ refers to the natural abundance of molecules containing two heavy isotopes, such as 13C18O16O, and is a measure of the preference of two heavy isotopes to clump together into a chemical bond. This preference is temperature dependent with the isotopes distributed randomly among all molecules at very high temperatures and are clustered together into a more ordered system at low temperatures.
This results in an isotopic parameter, ∆47, that can record the temperature in which these bonds were formed. ‘Clumped isotopes’ measurements are currently applied for 13C-18O bonds in CO2 molecules that are extracted either from carbonate minerals or from the atmosphere. In carbonates ‘clumped isotopes’ are used to determine the formation temperature of the mineral with most applications associated with reconstruction of past climatic conditions. In atmospheric CO2 it is used as a tracer for partitioning and quantifying the different CO2 sources and sinks of the global carbon cycle.
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Alon Amrani
Associate ProfessorHead of the Environmental Science Department972-2-65-85477alon.amrani@mail.huji.ac.ilRoom 204 NorthRead MoreInterests:
Organic geochemistry and biogeochemistry, stable isotopes, sulfur cycle, organic-inorganic interactions
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Simon Emmanuel
ProfessorRead MoreOur group studies nano-scale geological processes central to hydrology and the oil and gas industry. We use a diverse array of methods, combining cutting edge lab technology, state-of-the-art modeling, and field work. Current research projects include:
- Measuring mineral reaction rates during geological carbon sequestration
- Imaging crystal growth in nano-pores
- Analysing mechanical properties of rocks at the nano-scale
I am currently looking for creative students with backgrounds in Earth Sciences, Chemistry, and Physics to join our team. Students in the group are part of a dynamic research program that is developing exciting new projects at the interface between hydrology, geology, and geochemistry. For further information concerning MSc, PhD and postdoctoral opportunities, contact Dr Simon Emmanuel (swemmanuel@gmail.com).
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Yigal Erel
Kozenitsky-Rosenbach Professor of GeologyRead MoreMy research involves the application of trace-element ratios and Sr, Nd, Pb, Mo and Fe isotopic compositions to follow the fate of metals in the environment, in archaeological artifacts and in humans. The clean lab and our sensitive analytical instruments enable me and my students to study small-samples and/or materials with low elemental concentrations (e.g., dust samples, teeth and brain). Currently, my group is involved in research projects centering around:
1. Records of aeolian, fluvial and lacustrine sediments as tracers of paleo-environment conditions and sediment sources.
2. Tracing metal artifacts in antiquity.
3. The dark side of ancient metallurgy: Measuring toxic metals and metallic isotopes (and aDNA) in human populations and in artifacts to trace the impact of early industries through time.
4. The association between elemental anomalies in the human brain and mental diseases.
We carry out these projects in collaboration with researchers from the Hebrew University (Earth Science, Archaeology, Medicine), the Geological Survey of Israel, Israel Oceanographic and Limnological Research, The Israel Antiquities Authority, Tel Aviv University, Haifa University, GFZ - Potsdam, Germany, Columbia University, University of California San Diego, University of Michigan, and the Institute of Geology and Geophysics, Chinese Academy of Sciences.
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Ronit Kessel
Associate Professor
Head of the Geology Program
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The combination of experimental petrology and thermodynamic modeling provides powerful insights into the igneous and metamorphic processes by which Earth and other planets evolved. My research involves the development of experimental techniques together with modeling of the experimental data to constrain the nature of both terrestrial and extraterrestrial environments through the study of synthetic analogs.
The topics I am currently involved with:
Melt and fluid compositions in equilibrium with mantle material. Aqueous fluids play an important role in melting and metasomatism of the Earth’s mantle; I study the role of volatiles (H2O, CO2, etc.) in dehydration/hydration and melting processes in the mantle.
The evolution of meteorite groups. Samples delivered to the Earth as meteorites provide us with a unique opportunity to study the timing and the processes by which our solar system formed and evolved. I combine both experimental and analytical methods to understand the formation conditions of different groups of meteorites.
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Boaz Lazar
Professor
972-2-65-86535
boaz.lazar@mail.huji.ac.il
Room 5 South
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Research interests:
| My research has been focused on geochemical and biogeochemical processes at and near natural interfaces such as between water (saline/fresh) and rocks (or sediments or particles) and water-atmosphere boundaries. The research covers a wide-scale variety of geological environments. I have studied fluid inclusions within crystals, microgradients between seawater and electrode surfaces, stromatolites (microbial mats), coral reefs, porewaters within corals and sediments, floods and the open sea water column. A brief description of the research activities:Sr isotopes in ground waters as tracers of the calcite-calcite and calcite-dolomite transformations; Fluid inclusions in halite and the reconstruction of the chemical evolution of the oceans during the geological history; Diagenesis of reef corals and the distribution of trace elements (proxies for paleo-oceanographic conditions) between coralline aragonite and seawater; The fate of manganese in the soil-aquifer treatment of a sewage reclamation system; Isotopic effect of CO2 influx across brine-atmosphere interface induced by intense photosynthesis; 14C fluxes into marine sediments, across freshwater seawater interface, flood water and radiocarbon budgets; Carbon, oxygen and nutrients variations in coral reefs emphasizing the role of bioeroders, the decrease in reef calcification due to eutrophication, and suggesting that reefs will stop to grow on atmospheric CO2 doubling; Nutrients budget of the northern Gulf of Aqaba, Red Sea that enable to determine the role of fish farming in the eutrophication of that oligotrophic basin; Using the disequilibrium in the U-Th series, the cosmogenic isotopes 14C and 10Be for identifying atmospheric exchange, flood intensity, fluxes into porewater and water dating and analyzing the open system effect on dating corals by the U-Th method and studying water fluxes and adsorption/desorption kinetics. 4) |
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Oded Navon
ProfessorRead MoreResearch interest: I am fascinated by volcanoes, diamonds and pink granites*. Perhaps this is why I am interested in the role of water and other volatiles in magmatic processes. Volatiles are involved in most igneous processes. They are central in formation of melts, play a major role in transporting trace elements and radio-isotopes between mantle reservoirs or between mantle and crust, and are the driving force of explosive volcanic eruptions. In my studies, diamonds provide a window to the nature of deep mantle fluids. The geochemistry of Cenozoic alkali basalts, late-Proterozoic igneous rocks and lower crustal xenoliths from Israel is interpreted as reflecting progressive melting of hydrated lithosphere and is used to follow the transport of trace element between mantle and crust. Hydrothermal experimental setup is combined with computer simulations in a study of melt-fluid separation and interaction during volcanic eruptions.
* I must admit that I also love colorful sandstones, but I do not study these rocks or their coloration.
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Moti Stein
Professor (Adjunct)Read MoreInterests: isotope geology and geochemistry, igneous petrology,geochronology, paleolimnology, geochemistry of Dead Sea brines,geology of the Quaternary,paleoseismology
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