Salthill Quarry

© Craven & Pendle Geological Society

Salthill Cap Beds

Crinoidal Gravel Scree

Crinoidal gravel

Locality 6
Grid Reference [SD 756425]

This is the slope where good exposures of biosparite crinoidal limestone and cover mudstones have yielded a rich and diverse fauna of crinoids.  It is instructive to note the steep dips of these beds especially as these were deposited on a shallow slope!

There is an abundance of crinoid stems.  Less common today are the crinoid calyx's.  On death the calyx commonly breaks up.  Nevertheless, with patience, whole calyx's can still be found at this locality.

Of particular interest are the parasitic organisms that lived amongst the crinoid population.  The tabulate coral Cladochonus is commonly found here together with the curious gastropod Platyceras.

Also of interest are the plants that thrive on carboane soils. In August / September, the grassy part of the site is usually covered in Autumn Gentian (see next link).

The fossil crinoids continue to be of interest to the scientific community. Recently two papers on biotic interaction of Amphoracrinus gilbertosoni have been published:

Publications
Donovan, S. K., Lewis, D. N. and Kabrna, P. (2006). A Dense Epizoobiontic Infestation of a Lower Carboniferous crinoid (Amphoracrinus gilbertsoni PHILLIPS) by Oichnus paraboloides Bromley. Ichnos 13: 1 - 3

Donovan, S. K., Lewis, D. N. and Kabrna, P. (2005). An unusual crinoid-coral association from the Lower Carboniferous of Clitheroe, Lancashire. Proceedings of the Yorkshire Geological Society, 55, Part 4, 301-304