This research line utilises terrestrial cosmic-ray-produced (= cosmogenic) nuclides to investigate timescales and rates of earth surface processes to understand past climate and environmental conditions that have great implications to hominid migrations and settlements. This line is related to the Dating Cosmogenic Nuclide Laboratory.
Cosmogenic nuclides are the products of nuclear reactions between cosmic rays and elements in atmosphere and lithosphere on earth. Their production is the function of geomagnetic field intensity, exposure times and erosion rates. Measurements of cosmogenic nuclide concentrations allow us to determine the surface exposure ages at timescales from ~1000 years to several million years. Erosion rates as low as ~0.1 mm/k.y. up to 10,000 mm/k.y. can also be investigated. In addition, measurements of multiple cosmogenic nuclides enable us to calculate sediment burial ages from 400,000 years to 5 million years.
Among various cosmogenic nuclides, 10Be and 26Al produced in situ in quartz are the most widely used as quartz is ubiquitous and chemically resistant, and its simple crystal structure means the nuclide production rates are well constrained. Other types of nuclides include 36Cl in K-Ca-rich lithology (e.g., calcite/limestone, plagioclase/basalt) and 53Mn in Fe-rich lithology (e.g., hematite/banded iron formation).
10Be is also produced within atmosphere and falls out via precipitation, attached to soil particles on the ground. The 'meteoric' 10Be is useful for assessment of soil erosion, chronostratigraphy for marine/lacustrine cores (in combination with palaeomagnetism) as well as direct dating of sediment at timescales up to ~14 Ma.
The method is widely used in the field of earth sciences to date, including glacial, lava flow, fault scarp, catchment source-sink dynamics, sediment deposition in caves, fluvial/marine terraces and aeolian dunes.
Current projects include (collaborator, affiliation):
- Ice shelf dynamics in W Antarctica (PhD candidate, Mr Jeromson, U Canberra, AUS)
- Permafrost formation in Transantarctic Mountain (PhD candidate, Mr Anderson, U Otago, NZ)
- Impact of mining on basin denudation in Pilbara (PhD candidate, Ms Flatley, U Melbourne, AUS)
- Slope evolution in SE Queensland, Australia (PhD candidate, Mr Patton, U Queensland, AUS)
- Grounded ice behaviour in E Antarctica (PhD candidate, Mr Blaxell, U Canberra, AUS)
- Palaeorainfall reconstruction in central Asia (Dr Fitzsimmons, Max Planck, GER)
- Waterfall formations in N Australia (Dr May, U Melbourne, AUS)
- Wind erosion in yardang fields, southern Argentina (Dr May, U Melbourne, AUS)
- Neotectonics-fluvial interplay in Flinders Ranges, Australia (Dr May, U Melbourne, AUS)
- Late Cenozoic history of Duero, Ebro, and Guadiana basins (Dr Benito-Calvo, CENIEH)
- Incision history in Lobos Canyon, N Spain (Dr Bartolomé, Madrid Nat Museum)
- Deglaciation history in central Pyrenees (PhD candidate, Ms Vidaller, Inst Pirenaico Ecol-CSIC)
- Glacial history in Central Range, Spain (Dr Karambaglidis, CENIEH)
- Inception of Acheulian technology in Iberian Peninsula (Dr Panera, U Sevilla)
- Plio-Pleistocene paleoclimate reconstruction in Israel (Dr Waldmann, U Haifa, Israel)
- Direct isochron burial dating of stone artefacts in Olduvai Gorge (Dr de la Torre, Inst Historia-CSIC)
The following projects are under design and have potential PhD/postdoc opportunities:
- Palaeoenvironment in Lake Tanganyika, E Africa (Dr Sier, CENIEH)
- Human migration in Armenia (Dr Glauberman, Inst Archaeo Ethnography, Armenia)
- Palaeoecology & human settlement in West Mediterranean (Drs Parés, Duval, CENIEH; IPHES)
- Chronology of Atapuerca cave systems (CENIEH)
- Cave chronology in Ojo Guareña (Dr Ortega, CENIEH)
Please contact Dr Toshiyuki Fujioka (email@example.com) for any enquiry including research collaboration and technical consultation.