20
4
January
907
912
SPICER, R. A. 1978. The pre-depositional formation of some leaf impressions. Palaeontology, 20, 4, 907–912.
Robert A. Spicer Observations show that an inorganic sedimentary encrustation may be built up on plant leaves within a few weeks after entry into a depositional environment. Such an encrustation may be the basis of a detailed impression fossil. SEM examination and X-ray microanalysis of this encrustation on freeze-fractured, freeze-dried leaves reveals preferential deposition of fine-grained, iron-rich material that faithfully replicates the epidermal surface detail of the leaf. By analysis, fossil-leaf impressions from the Upper Cretaceous Dakota Sandstone of Kansas are shown to have a similar elemental composition. A possible biogenic origin for the surface encrustation is suggested. The Palaeontological Association (Free Access)