The fauna of the Chazy limestone / by Percy E. Raymond.

  • Raymond, Percy Edward, 1879-1952.
Date:
[1905]
Catalogue details

Licence: In copyright

Credit: The fauna of the Chazy limestone / by Percy E. Raymond. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Pi vision 3.—Tliis is es})ecially well develo|:>e(] on Yalcoiir Island. Zone 3,^ is exposed in two or three localities on tlie east side. Zone 3,, is best developed about Cystid Point, the southeast point of Yalcour Island, and zone 3^ is ex|)Osed l)oth east and west of Black Piver Point on the north end. The division is 1T2 feet in thickness and carries Camarotoechia 2)lena thi-onghout. The fannides given for zones 3^, 3^, and 3., are those found on Yalcour Island. Crown Point t3ection.^' The section at Crown Point is 305 feet in thickness. At the base is a zone 25 feet thick in which the strata are sandstone and shale, and the only fossil is Linyida Ijrainerdi. The remaining 280 feet are impure blue and grey limestone, usually very fossil if erous. Division 1 is absent. Pi vision 3.—The fauna chai-acteristic of this division is found all through the section at Crown Point. The character- istic fossils—Maclurites mayna, Rafnesquina charnjjlainensis.^ Plaesiomys platys.^ and Lejoerditia limatida—are very abun- dant, and the whole expression of the fauna is that of the mid- dle part of the section at Yalcour Island and elsewhere. Brainerd and Seely assign the lower 48 feet to their Division A, and the upper 57 feet to Division C, but faunally the whole section belongs together. Camarotoechia plena, is absent, as are also the other fossils characteristic of Division 3. Tlie upper 3 feet of the section are a coarse limy sandstone, with Plcesiomys q^latys.^ Camarella vavians., Raphistoona starnin- eum.^ and Isotelus harrisi in a layer a foot thick at the top. Orwell,, Vermont. A short distance northeast of Orwell villao:e is the most southern exposure of the Chazy. At that place there are about 60 feet of strata,.the fauna of which indicates that they belong to Division 2. Another locality near by shows sand- stone and shale at the base of the formation. North of the International Boundary the various divisions can not be followed in the published lists, but this is due to the fact that no sections liave been made in tiiat region. The lists published by Billings, Logan, and Ami, of the Canadian Sur- vey, however, do show that fossils characteristic of all three divisions are found in that region. The Champlain Yalley fauna of the Chazy, which will be designated as the typical one, is found as far north as Joliette, 35 miles north of Montreal and * For detailed description of this section, see Bull. Anier. Pal., vol. iii, No. 14, 1902.