Tectonics, climate and long-term evolution of the Nile drainage system using Pb isotopes in detrital feldspa

The Nile delivers sediment to one of the Earth's largest and most sensitive deltas and its offshore extension, the Nile Cone. The latter has become a major hydrocarbon province and wells and cores provide samples of the ultimate repository for sediment passing down the developing drainage system.The ancestral Nile has fed sediment to the eastern Mediterranean since at least the Oligocene. Although the modern (pre-dam) sediment load is dominated by volcanic lithic sands sourced from the Ethiopian Highlands, older sandstones in subsurface cores are quartzo-feldspathic, implying major changes in sand source areas and hinterland drainage through time.
The research project will focus on characterising the common Pb isotopic compositions of detrital feldspar grains in Miocene to Pleistocene sandstones from the Nile cone subsurface and comparing these to prospective basement source terranes and samples from the modern Nile tributaries. The new data will help constrain the development of Earth's longest river system, the onset of hyper-arid conditions in the eastern Sahara, teleconnections between climate, runoff and Mediterranean oceanography, and the influence of rift-shoulder and triple-junction uplift on sand supply. The study will also help develop the Pb-tracing technique by applying it to a large extant drainage system for the first time. The results will tie in to a wider provenance effort using other provenance tracers involving the universities of Lancaster, Aberdeen and Milano-Bicocca and using shared subsurface samples provided by BP. The Pb isotopic composition of both K-feldspar and plagioclase will be determined using an in-house laser ablation system attached to a Thermo-Fisher NEPTUNE MC-ICPMS at the National Centre for Isotope Geochemistry (NCIG), University College Dublin. Training in subsurface data interpretation, petrographical and grain imaging techniques and laser-abalation mass-spectrometry will be provided. There will also be opportunities to join field parties sampling the modern drainage and potential source blocks, and to collaborate with the other research teams.
Funding, through a Griffith Geoscience Research Award to the Marine and Petroleum Geology group at UCD, is for four years. The successful applicant will enter a structured PhD programme in the UCD School of Geological Sciences. The stipend will be €18,000/year and fees, field and conference travel, and analytical costs will also be covered. Prospective candidates should contact Dr Peter Haughton in the first instance, including a CV and a covering letter explaining your interest in the project (e-mail to Peter.Haughton@ucd.ie). Please provide contact details for three academic referees with your application. The deadline for receipt of applications is 24^th February 2012 for a summer 2012 start-up.

Source:  http://www.earthworks-jobs.com