APPLICATIONS OF NEUTRON IMAGING IN PALAEONTOLOGY

Neutron imaging is a non-destructive, diagnostic technique that provides information on the presence, position, size, morphology, and chemical composition of structures within bulk materials. It shares fundamental similarities with x-ray techniques but the information obtained is complementary, meaning that neutrons are often applicable in circumstances where x-rays are not. For example, neutrons are able to penetrate thick layers of material (including many heavy metals) but are highly sensitive to hydrogen. Neutron imaging techniques have been successfully applied to scientific research disciplines as diverse as fundamental physics, materials science, archaeology, botany and palaeontology.

Imaging experiments have been performed on fossils at the cold neutron radiography and tomography station (CONRAD) at the Helmholtz Centre Berlin for Materials and Energy, Berlin, Germany. The fossils comprise exceptionally well-preserved plant material (branches, twigs, leaves, cone scales and seeds), which have been identified as an extinct relative of Araucaria araucana, the monkey puzzle tree. These conifers are thought to represent the dominant vegetation growing in dense forests on the slopes of an active volcanic arc at 65°S (now the Antarctic Peninsula) during the late Early Eocene Era (approximately 53 million years ago). Images obtained from one specimen show that a considerable part of the fossil is hollow, but the high contrast of the regions of fossilised material suggests that it may contain remnant hydrogenous material.