RESEARCH INTERESTS and CURRENT PROJECTS  

[1] PALEOCEANOGRAPHY / MARINE BIOGEOCHEMISTRY

         A. Quantifying deep sea calcite dissolution

G. menardii fragmentation index [MFI]

We developed a deep sea carbonate dissolution proxy by anchoring the fragmentation trend of G. menardiis against estimates of percent calcite dissolved using the biogeochemical model, Muds. 

We are currently in the process of expanding the calibration range and down core applicability of our proxy. See Mekik, et al[2002, 2010] for its calibration details. Also Mekik and Francois, [2006] established support for MFI from Mg/Ca in shells of G. menardiis and P. obliquiloculatas.

See Mekik et al., 2012 for MFI's downcore applicability.

        B. Rain Ratio: the organic carbon to calcite flux ratio to the deep sea

I am working on quantifying the flux of calcite from the surface ocean to the deep sea and the potential of deep ocean waters for regulating atmospheric pCO2 over tens of thousands of years. The rain ratio is one of the two main controls on carbonate dissolution in the deep sea. This is  a map of the rain ratio we modeled for the eastern equatorial Pacific using surface ocean bioproductivity data from literature, the G. menardii carbonate dissolution index and biogeochemical modeling

Most recently, we have been using 230Thorium normalized sediment accumulation rate data and our carbonate dissolution proxy based on fragmentation of G. menardiis to calculate calcite fluxes for specific locations in the eastern equatorial Pacific. This will give us a more data-based map of the rain ratio for this region than the one shown here. Our work is still in progress. Actually our paper is in press in Deep Sea Research II.

        C. In search of the deglacial carbonate burial maximum in the deep sea:

We are using our carbonate dissolution index and carbonate burial rates in down core sediment samples to find the deglacial carbonate preservation maximum which must exist as a consequence of post-glacial atmospheric CO2 rise. In most places of the equatorial ocean the preservation and burial data is obscured by bioturbation and changes in ocean circulation. This work was recently published in Quaternary Science Reviews (Mekik et al., 2012)

 

[2] RADIOLARIANS, OCEANOGRAPHY and MÉLANGES                                             

Geology is a fun science and geologists get to travel to many exotic places in the world. I am from Turkey. I study ancient micro-organisms that can help us unravel the timing and story of mountain building around Ankara: Turkey's capital.. Turkey is rich with research opportunities with its many mélanges and thick sequences of fossil-rich rocks. Click here for a picture of the sedimentary mélange in Ankara, Turkey.