Marine and Environmental Geochemistry
Marine Geochemistry studies all processes that influence the
chemistry in the water. The chemical cycles in the oceans are closely related
to processes in the atmosphere and terrestrial systems as well as to biological,
and recently anthropogenic, activity. Marine Geochemistry also studies the sediments,
including the pore waters as well as the abiotic and biotic processes that take
place within the sediment. Currently our research at Stellenbosch University
focuses on macro-nutrient (e.g., N, P, Si) and trace metal cycling in the modern
ocean (e.g., Fe, Mg, Zn, Cd, Co, Cu), interactions with biological organisms
(especially with microbes and algae), and impact of atmospheric deposition
(dust). We currently focus on the Atlantic sector of the Southern/Antarctic Ocean and the west coast of southern Africa.
contact(s): Prof. Roychoudhury (send e-mail) or Dr. Susanne Fietz (send e-mail)
facebook: Environmental Geochemistry at Stellenbosch University
Blog: https://southernoceanfe.wordpress.com

Overview of ocean-land-atmosphere-biosphere interactions studied at Stellenbosch University, Earth Sciences
Most of our marine research projects sampling and experiments are conducted on board SA's flagship, the research vessel/icebreaker SA Agulhas II
Geochemical proxies for paleo-climate reconstructions
Climate and the environment are ever-changing, driving human
activity in the past and being altered by human behaviour in the present and
future. Understanding the past is crucial for predicting future climate
scenarios. Instrumental analysis is limited to a few centuries, but sediments,
peats and speleothems offer a window into the climate of the past. There is no means of directly measuring the past air or water temperature, or soil pH, or ocean acidity etc. The
reconstructions are thus based on microfossils, isotopes, and biomarkers preserved
over millions of years. At Stellenbosch University, Earth Sciences, we mainly
focus on molecular biomarkers, organic compounds derived from microbes that provide
clues about regional temperature variability, environmental forcings (e.g., dust deposition) and
ecosystem functioning (e.g., algal and microbial community).
contact(s): Prof. Roychoudhury (send e-mail) or Dr. Susanne Fietz (send e-mail)
facebook: Environmental Geochemistry at Stellenbosch University
(left) A sediment core is just like a history book. Cutting section by section, it provides clues to the past that we can use to understand the present and project the future.
(below) Examples of sediment core sections from the Pacific Southern Ocean: a) laminated diatom ooze, b) Nannofosil ooze
(below) coring long piston cores in a lake and at sea
