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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    There are three well-marked zones in this division, as fol- lows : Zone ITn GJapliuvas jmstalatas zone, is fV>nnd at the base of Division 3, at Yaleoni- Island, Chazy, Cooj^erville, and Isle La Motte. The chai’acteristie fossils are: Glajdrarus pustulatus., rilce)ni8 gloJ)Osas^ 1. erasiusi^ Jsotelus harrisi^ Reniopl ear ides canadensis^ Pliomerop)s ca/naden sis., Amphili- chas niin(/a)iensis., Jdseudosjdaerexoch us vuJcanus., Camarotm- chia plena., Conocardium heecheri sp. nov., Bttcania sulcaiina., and several cephalopods. Zone IL, the Camaroimchia. mayor zone, stands between 3^, and 3^ and its fannule is a transition between the two. Gama rot oechia becomes more abundant and better developed, and fossils, while nnmerons, become fewer in s])ecies. The best develo])inent is at Valconr Island. The characteristic fossils are: CamarotoeGhiaplena^ C. majot\ Tlehertella costalis^ Mcdocystites emmonsi. Malocystites s])., Palceocystites sp., Illmius glohosus, Pliomerops canadensis., Bucania sulcatina., Raphistoma stamineum^ and Isotelnis ohtusum. Zone 3^. The Modwlopsis fahaforniis zone. In this zone, Camarotcechia pdena is abnndant, almost to tbe exclnsion of other species. The fannnle extends to the to]:> of the formation at Chazj, G]*and Isle, and Yalconr Island. The cliaracteristic fossils are : Camarotoechia plena and Modiolopjsis faha for mis. Section at Chazy., Neic York. The section at Cliazy lias a thickness of 732 feet, but the base of the formation is not shown. Division 1.—The rocks carrying the fauna of Division 1 are well exposed in the ridges south of the village, near Tracy Brook. The thickness is 305 feet, and judging from the fauna at the base, at least 150 feet of strata are missing. Ilehertella eocfoliata is very abundant, especially below the horizon of Scalites angidatus. The latter zone is 217 feet above the base of the exposed section, and is zone Y of the generalized sec- tion. The most common fossils are : Secdites angidatus, Buca- nia sulcatina, Raphistoma immaturum, R. stamineum, and dlialeops ovata. Higher up in the section, 275 feet above tlie base, is the zone of Lophospira suhahhreviata, about 35 feet in thickness. This is zone 1^ of the generalized section. The gastropods ai-e very abuudant in the three localities at Chazy where this zone is exposed. Division 2.—The strata of this division are about 195 feet in tliickness, and are dark blue, impure nodular limestones, usually full of fossils which are frecpiently silicilied. Stroma-