Middle Hettangian (Lower Jurassic) ammonites from Isle of Raasay, Inner Hebrides, and correlation of the Hettangian-lowermost Sinemurian Breakish Formation in the Skye area, NW Scotland

Liasicus Zone (middle Hettangian) ammonites, allocated to a new species, Fr anziceras sorleyi, are described from Hallaig, Isle of Raasay and indicate that the Breakish Formation (formerly lower Broadford Beds) there is older than previously thought. The new finds have been integrated with the limite d available biostratigraphic information from the rare records of Hettangia n and basal Sinemurian ammonites, and with local lithostratigraphy based on marker beds, to develop a new interpretation of correlations within the Sk ye-Raasay-Applecross area. This concludes that there was a diachronous earl y Jurassic transgression and facies change from the continental red beds of the Stornoway Formation into the marginal marine carbonate-dominated sedim ents of the Breakish Formation.