Data from: Visualizing mineralization processes and fossil anatomy using synchronous synchrotron X-ray fluorescence and X-ray diffraction mapping

Fossils, including those that occasionally preserve decay-prone
soft-tissues, are mostly made of minerals. Accessing their chemical
composition provides unique insight into their past biology and/or the
mechanisms by which they preserve, leading to a series of developments in
chemical and elemental imaging. However, the mineral composition of
fossils, particularly where soft-tissues are preserved, is often only
inferred indirectly from elemental data, while X-ray diffraction that
specifically provides phase identification received little attention.
Here, we show the use of synchrotron radiation to generate not only X-ray
fluorescence elemental maps of a fossil, but also mineralogical maps in
transmission geometry using a two-dimensional area detector placed behind
the fossil. This innovative approach was applied to millimetre-thick
cross-sections prepared through three-dimensionally preserved fossils, as
well as to compressed fossils. It identifies and maps mineral phases and
their distribution at the microscale over centimetre-sized areas,
benefitting from the elemental information collected synchronously, and
further informs on texture (preferential orientation), crystallites size
and local strain. Probing such crystallographic information is
instrumental in defining mineralization sequences, reconstructing the
fossilization environment and constraining preservation biases. Similarly,
this approach could potentially provide new knowledge on other
(bio)mineralization processes in environmental sciences. We also
illustrate that mineralogical contrasts between fossil tissues and/or the
encasing sedimentary matrix can be used to visualize hidden anatomies in
fossils.