Synchrotron X-ray microscopy of marine calcifiers: how plankton record past climate change

X-Ray Microscopy Conference 2016

Redfern, S.A.T.^1 ; Branson, O.^1,2 ; Read, E.^1

Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge

CB2 3EQ, United Kingdom^1

Research School of Earth Sciences, Australian National University, Mills Road, Acton

ACT

2601, Australia^2

关键词: Biogenic carbonates;    Chemical environment;    Chemical variations;    Climate variation;    Environmental influences;    Geochemical signatures;    Nanoscale structure;    Synchrotron x rays;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/849/1/012011/pdf
DOI  :  10.1088/1742-6596/849/1/012011

来源: IOP

【 摘 要 】

We have used STXM and PEEM to reveal the underpinning chemistry and nanoscale structure behind palaeo-climate geochemical signatures, such as trace Mg in shells- proposed proxies for palaeo-ocean temperature. This has allowed us to test the chemical assumptions and mechanisms underpinning the use of such empirical proxies. We have determined the control on driving chemical variations in biogenic carbonates using STXM at the absorption edge of Mg, B, and Na in the shells of modern plankton. The power of these observations lies in their ability to link changes in chemistry, microstructure, and growth process in biogenic carbonate to environmental influences. We have seen that such changes occur at length scales of tens of nanometres and demonstrated that STXM provides an invaluable route to understanding chemical environment and key heterogeneity at the appropriate length scale. This new understanding provides new routes for future measurements of past climate variation in the sea floor fossil record.