TABULATA AND HELIOLITOIDEA CORALS FROM THE LOWER DEVONIAN (PRAGIAN) SODA CREEK LIMESTONE, FAREWELL TERRANE, WEST-CENTRAL ALASKA

The following Tabulata and Heliolitoidea corals are documented from the Lower Pragian (Lower Devonian) Soda Creek Limestone (Farewell terrane) of west-central Alaska: Favosites admirabilis, Favosites tarejaensis, Gephuropora multiplicatus, Squameofavosites bohemicus, Squameofavosites obtusispinosus, Squameofavosites nexus, Echyropora vijaica, Echyropora (?) sp., Pachypora cylindrica, Striatopora tschichatschewi, Striatopora magna, Parastriatopora rzonsnickajae, Yacutiopora innae, Yacutiopora khalfini, Alveolitella karmakensis, Scoliopora inconstans, Caliapora sp., Crassialveolitella? sp., and Pachycanalicula dentata. These species indicate Asian faunal influence, being common in Lower Devonian (mainly Pragian) localities in NE Asia, West and SW Siberia, Taimyr, and the Urals-Novaya Zemlya region. In contrast, the foregoing species association shows negligible similarity with Lower Devonian Tabulate corals known from cratonic North America.

Many of the Soda Creek tabulate species are typical for Tom-Chumysh and Krekov Horizons of SW Siberia and also for lower and middle Pragian Sagyrsky Formation of East Siberia. Yacutiopora khalfini, Pach. dentata and F. admirabilis are known from the Tom-Chumysh Horizon and F. admirabilis, P. rzonsnickajae, Sq. obtusispinosus and Str. tschichatschewi are typical for Krekov Horizon of Kuznets Basin and Y. innae, S. inconstans, F. admirabilis and P. rzonsnickajae are characteristic for Sagyrsky Formation of NE Siberia.

Noticeable among the Tabulate corals are representatives of Yacutiopora. The genus is characteristic for the Lower Devonian of NE Asia, West and SW Siberia. Y. innae (Dubatolov), reported here in the Soda Creek Ls., is widely distributed in different parts of Siberia.

Based on the common occurrence of F. admirabilis, Sq. obtusispinosus, Sq. bohemicus sensu Alkhovik, Sq. nexus, P. rzonsnickajae, Str. magna and A. karmakensis, significant similarity is also noted between Tabulates from the Soda Creek with those of the Uryum and Tolbat Beds of Taimyr. Additionally, several of the Soda Creek Tabulates are known from the Nelichenskaya Formation of East Siberia (Upper Pragian) and Salairka Horizon of SW Siberia (?Upper Pragian-Emsian): G. multiplicatus, Pch. cylindrica, S. tschichatschewi and Sq. obtusispinosus.