INFERIOR OOLITE.
This formation consists of a calcareous freestone, usually of small thickness,
but attaining in some places, as in the typical area of Cheltenham and the
Western Cotswolds, a thickness of 250 feet. It sometimes rests upon yellow
sands, formerly classed as the sands of the Inferior Oolite, but now regarded as
a member of the Upper Lias. These sands repose upon the Upper Lias clays in the
south and west of England. The Collyweston slate, formerly classed with the
Great Oolite, and supposed to represent in Northamptonshire the Stonesfield
slate, is now found to belong to the Inferior Oolite, both by community of
species and position in the series. The Collyweston beds, on the whole, assume a
much more marine character than the Stonesfield slate. Nevertheless, one of the
fossil plants Aroides Stutterdi, Carruthers, remarkable, like the Pandanaceous
species before mentioned (Figure 347) as a representative of the
monocotyledonous class, is common to the Stonesfield beds in Oxfordshire.
(FIGURE 350. Hemitelites Brownii, Goepp. Syn. Phlebopteris contigua, Lind.
Pages:
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653