A Monograph of the Gault

From the INTRODUCTION. The Gault is a deposit of blue, grey, and sometimes of reddish clays and marls, which are met with in the middle of the Cretaceous strata above the topmost beds of the Upper Neocomian formation viz. the zone of Ammonites mammillaris, and is by the majority of French geologists looked upon as Gault; but English geologists differ as to this division, the reason for which will be given further on in this work. The lower beds of the Gault in Kent, Sussex, Surrey, Cambridg...