An investigation of Laser Induced Breakdown Spectroscopy for use as a control in the laser removal of rock from fossils found at the Malapa hominin site, South Africa

Laser Induced Breakdown Spectroscopy (LIBS) was used to study the spectra from fossils and surrounding rock recovered from the Cradle of Mankind site at Malapa, South Africa. The objective was to find a suitable spectral line(s), specific to fossils, which could be used as a control signal to limit damage to fossils during high speed laser removal of the encasing rock. The calcified clastic matrix (rock) encasing the fossils was found to emit a variety of complex LIBS spectra. Nevertheless, it was found possible to distinguish fossils in a single LIBS pulse, and without significant damage to the fossil, using spectral lines of neutral phosphorus.

► LIBS used to discriminate fossils from rock as potential processing control mechanism.
► 2 million year old fossils from Malapa hominin site found to be high in phosphorus.
► Rock spectral lines from silicon, iron and manganese, but no phosphorus.
► Holds great promise for process control in laser preparation of fossils.
► Also promising for accurate identification of fossils at excavation sites.