JSTOR: Journal of Paleontology: Vol. 49, No. 1, p. 93 Page 2 of 3 Doc. 137 [illegible] DEVONIAN DALMANITACEAN TRILOBITES I. Saint-Léon and a. Grande Grève of Clarke (19[µ] older Formations and older authors II. York River and b. Grande Grève of National younger Formations Topographic Map 22 A/16 Cap-des-Rosiers Cove Cap Bon Ami GULF OF SAINT-LAWRENCE Dolbel Brook Cap Bon Ami Formation Grande a Grève Formation coulée II Cap Petit Gaspé Gave prépente b Indian Cove Cape Gaspe Shiphead GASPÉ BAY TEXT-FIG. 1--Map of the Forillon peninsula, Quebec. and bentonitic layers with an uppermost 1.5 m (5 ft) thick of "grass-green" beds (glau- conic shales and glauconitic calcarenites). Overlying this lower member is the Indian Cove Member, approximately 183 m (600 ft) thick of cherty limestones. A continuous sec- tion of the lower member is exposed, and fos- sils are therein easy to collect; no continuous section of the upper member has ever been followed, as its outcrop is largely parallel to the strike of the beds. Fossils in the Indian Cove Member, although plentiful, are difficult to extract, and silicified specimens are more easily collected. Problems facing the stratigraphy of the Grande Grève Formation are twofold. Firstly, the lithology of the Grande Grève Formation changes westward and, secondly, the faunas previously described from the type area of the Formation are assigned only with difficulty (if at all) to the present lithostratigraphic framework. The Grande Grève Formation extends some 225 km (140 miles) west of Cape Gaspé. In these areas away from the Forillon peninsula, the Grande Grève Formation is commonly dis- tinguished from the underlying Cap Bon Ami Cumming, 1959) are best assigned to Saint-Léon Formation. There is thus littl common between the Grande Grève Forma tion of the Forillon peninsula, and the strata ca by the same name farther west. The for tional names applied by those who map a particular area will be used here and ages of the trilobites from these beds will those ages obtained from the accompany brachiopods (identified by A. J. Boucot) Biostratigraphy.--The age assignment of the described fossils from the Forillon pe sula is a vexing problem. Sir W. E. Lo (Logan et al. 1863) named the strata of Forillon peninsula the "Gaspé Limeston and divided them into eight units (comm referred to as "members") (Text-fig. 2). U 8 corresponds exactly to the Indian Cove M er of L. S. Russell; unit 7 on the other h differs. The Shiphead Member is 39 m (128 thinner than Logan's unit 7, although the s upper contact of the "grass-green beds" Shiphead is used as a boundary between strata. Billings (1874) began a description the fossils of the Gaspé Limestones; the jority of the fossils described came from 8 and none is identified as coming from u http://www.jstor.org/view/00223360/ap040280/04a00070/2?frame=noframe&userID=82... 10/29/2007