Ground-based hyperspectral imaging combined with terrestrial lidar scanning
is a novel technique for outcrop analysis, which has been applied to Early and
Late Albian carbonates of the Pozalagua Quarry (Cantabrian Mountains, Spain).
An image processing workflow has been developed for differentiating
limestone from dolomite, providing additional sedimentary and diagenetic
information, and the possibility to quantitatively delineate diagenetic phases in
an accurate way. Spectral absorption signatures can be linked to specific
sedimentary or diagenetic products, such as recent and palaeokarst,
hydrothermal karst, (solution enlarged) fractures and different dolomite types.
Some of the spectral signatures are related to iron, manganese, organic matter,
clay and/or water content. Ground-truthing accessible parts of the quarry
showed that the classification based on hyperspectral image interpretation was
very accurate. This technique opens the possibility for quantitative data
evaluation on sedimentary and diagenetic features in inaccessible outcrops.
This study demonstrates the potential of ground-based imaging spectroscopy to
provide information about the chemical–mineralogical distribution in outcrops,
which could otherwise not be established using conventional field methods.