Age and Thickness.

The beds belonging to this formation contain a large number of species of which, according to Captain Hutton, who has carefully studied them, 37 per cent. are identical with living forms, and consequently they ought to be classed as upper miocene. Considering that we are not yet fully acquainted with the molluscan fauna of our seas, except with that of the Littoral Zone, it is very possible, that when dredging operations can be carried on on a large scale, many of the species we now believe to be extinct, will be found still living. Consequently the number of living species will be augmented. In such a case, the age of the Pareora formation would be lower pliocene.

Although in many localities the beds of which this formation is composed are only a few hundred feet thick, in others, as for instance, in the middle and lower Waipara and the Waihao, they have an aggregate thickness of as many thousand feet, arenaceous material in the form of sands having been deposited in great abundance along the coasts in a shallow sea.

The name Pareora formation was first applied by me to these beds, in 1864, when examining the Pareora river, where they are well developed, this designation being adopted by Dr. Hector and Captain Hutton. It includes tho Kanieri group (lower portion), of Captain Hutton, and the Awatere group (upper portion of von Hochstetter).