Article: Palaeoecological studies in the Great Oolite at Kirtlington, Oxfordshire
W. S. McKerrow, R. T. Johnson and M. E. Jakobson
Middle Jurassic (Bathonian) limestones and clays at a quarry north of Oxford have yielded faunas, some of which are life assemblages, and others which have been transported before burial. Size distributions and articulation ratios are among the criteria discussed for distinguishing between the life and death assemblages.The White Limestone, the lower of the two formations studied, consists of two facies: (a) limestones disturbed by burrowing molluscs, worms, and crustaceans which are interpreted as having lived in inter-tidal flats; and (b) channels cut into the inter-tidal deposits, which are either poorly fossiliferous or which contain an epifauna of terebratulid brachiopods (Epithyris) and mussels (Modiolus); the floors of these channels were sub-tidal.The inter-tidal facies continues locally into the basal metre of the Forest Marble, but this higher formation is dominantly sub-tidal. The Forest Marble (in Oxfordshire) is distinguished from the White Limestone in containing an abundant epifauna (with a large proportion of oysters) and few signs of bioturbation. Shelly limestones and clays with lignite are the characteristic Forest Marble lithologies; one coral-Epithyris bed is present which contains a mixture of drifted and endemic forms.