phosphatic

The dissolution of limestones in weak acid is now a standard palaeontological laboratory technique, and has been used extensively to isolate 'phosphatic' microfossils of all types from Paleozoic carbonates.

The sample was taken from a thin limestone lens with phosphatic oolites within the 'phosphatic' greensand.

The basal part of the transgressive sandstone contains erosion surfaces, reworked bioclasts, 'phosphatic' and glauconite pellets.

In time the combination solidifies to a 'phosphatic' rock that, in crumbling, provides soil in which vegetation may take root.

Nodules rich in 'phosphatic' material are found in residual accumulations along disconformities, such as bone beds or lag deposits in marine limestones and shales.