NANOPROBES FOR DEEP CARBON

The deep carbon cycle plays a key role on the evolution of the atmosphere and life on the planet. Surficial observations reveal carbon in a great variety of organic, inorganic, and biological forms which subduct with descending slabs and rises and erupt in volcanoes. Little is known about the nature and the extent of deep carbon reservoirs as well as how carbon moves from one deep reservoir to another. Several questions related to the chemistry and physic of carbon at high pressure and high temperature remain to be answered: e.g. what is the state of carbon in the deep Earth? In what form do carbon-bearing materials exist deep within the Earth? With what others materials do they react and how quickly? How is it transported within the planet’s deep interior?

Experimental study of materials behavior at extreme conditions requires the ability to reach simultaneous extreme pressure-temperature conditions, and the development and implementation of a battery of micro/nanoscale probes to characterize samples. In addition, studying carbon brings its own set of complications and considerations. Several ex-situ and in-situ techniques have been recently developed and can now be used for investigating deep carbon. In this presentation we will first review some of the techniques for reaching ultrahigh pressures and temperatures focusing on the laser-heated diamond anvil cell (DAC). We then discuss state-of-the-art ex-situ techniques for studying quenched carbon-bearing samples with nanoscale resolution. Significant progress has been made to bring the study of the deep Earth on par with the capabilities available for surface studies, and we will discuss some of the in-situ techniques most relevant to studying carbon. Finally we will look ahead to future developments and prospects for the experimental study of deep carbon.