BRACKISH-WATER FAUNAS FROM THE ST-MAUGHANS FORMATION - THE OLD RED SANDSTONE SECTION AT AMMONS-HILL, HEREFORD AND WORCESTER, UK, REEXAMINED

The disused railway cutting at Ammons Hill, Hereford and Worcester, ex poses a sequence of beds belonging to the Devonian St Maughans Formati on of Lochkovian (Gedinnian) age. The beds are of Old Red Sandstone fa cies, but contain brackish water faunas. These faunas occur at a level generally considered to be above the level of marine influence that a ffected the older Raglan Mudstone Formation of mainly Pridoli Series a ge. The section, described by King in 1934, is now overgrown, but was excavated in 1986 by the British Geological Survey during its survey o f the Worcester 1:50000 sheet. The evidence of the section calls for s light amendment of Alien's (1985) model of an interrupted transition f rom marine deposition in Ludlow time to freshwater deposition in Gedin nian time that was complete by the time of the formation of a regional ly extensive calcrete palaeosol, the Psammosteus Limestone. Subsequent transgressive events took place before the establishment of apparentl y wholly fluvial and floodplain environments.