| mhorn | Дата: Saturday, 28.07.2012, 11:51 | Сообщение # 1 |
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| Caruthers A.H., Smith P.L. (2012) Pliensbachian ammonoids from the Talkeetna Mountains (Peninsular Terrane) of Southern Alaska // Revue de Paléobiologie, Vol. spéc. 11. P.365-378.
http://www.ville-ge.ch/mhng/paleo/paleo-pdf/spec-11/pal-spec-11-25.pdf
In this study we describe Late Pliensbachian ammonites from two stratigraphic sections of the Talkeetna Formation exposed in southern Alaska. Ammonites indicate the Kunae Zone in the Camp Creek section and Carlottense Zone in the Hicks Creek section. An interbedded ash within the Camp Creek section provides a 206 Pb/238U TIMS age date of 184.12 ± 0.17 Ma from the uppermost Kunae Zone, very close to the base of the overlying Carlottense Zone which is currently calibrated at 184.1 + 1.2/-1.6 Ma). Ammonoid taxa described in this study represent the Tethyan, Boreal, and East Pacific Realms and include: Amaltheus sp., Arieticeras aff. domarense
(meneghini), Fanninoceras (Fanninoceras) carlottense mClearn, Fanninoceras (Fanninoceras) fannini mClearn, Fanninoceras (Charlotticeras) cf. maudense smith & tipper, Leptaleoceras? sp., Lioceratoides (Lioceratoides) cf. involutum smith & tipper, and Lytoceras sp., of which Fanninoceras (Charlotticeras) cf. maudense, Leptaleoceras? sp., and Lioceratoides (Lioceratoides) cf. involutum are new to Alaska
Middle Jurassic - Lower Cretaceous ammonites & aptychi
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