Jurassic paleobiogeography of Alaska

Abstract

FIGURES 1-9. Maps showing distribution of Jurassic fossils in Alaska: 1. All stages of the Jurassic ______ _____________. 2. Hettangian and Sinemurian ______-__________ __ ___. 3. Pliensbachian and Toarcian ____-_-______ __ _. 4. Bajocian ___________________ ______ _____ ______. 5. Bathonian and Callovian ___________ ________________ 6. Early Oxfordian ______________________________. 7. Late Oxfordian to early Kimmeridgian _ _____. 8. Late Kimmeridgian to early middle Tithonian __________. 9. Late middle to late Tithonian ____ ________________. 10. Index map of Jurassic areas in Alaska _____________________ 11. Correlation charts of Jurassic rocks in Alaska-_ ____________________ 12-15. Chart showing 12. Occurrences of unconformities in the Jurassic of Alaska _ _. 13. Correlation of Hettangian to Toarcian ammonite faunas in Alaska. 14. Correlation of Bajocian to Callovian ammonite faunas in Alaska 15.

Post-Carboniferous stratigraphy, northeastern Alaska

“…Age.-The Kingak Shale was considered to be Early Jurassic by Leffingwell (1919, p. 119 (Imlay and Detterman, 1973). These fossils are from the fissile clay shale and claystone in the lower part of the sequence.…”

Biostratigraphy of the Snowshoe Formation (Jurassic) in the Izee area, Grant County, Oregon

“…These specimens, together with the specimens discussed by Imlay (1967Imlay ( , 1973, probably represent the variants of a new species of Stemmatoceras related to S. a l be rt en se but differing in having more closely spaced primaries on the inner whorls, more distant primaries on the outer whorls, slightly fewer and sharper secondary ribs and a slightly higher whorl section.…”

“…Furthermore, this ammonite appears to be identical with the ammonites from the lower and middle Basey Member of the Snowshoe Formation that Imlay assigned to Sphaeroceras sp. (Imlay, 1973, especially pl. 40, fig.…”

“…(Imlay, 1973, p. 19~ Morton, 1975. EuhopZoaePas is restricted to the Disaites Zone (Westermann, 1966, p. 19) but has been reported from the upper Conaavum Zone (Morton, 1975, passim) and also associated in the upper part of its range with PapiZZiaeras in Oregon (?…”

Hydrocarbon potential, geologic hazards, and infrastructure for exploration and development of the lower Cook Inlet, Alaska

“…The marine fauna suggests an Early Jurassic age for these sedimentary rocks (Martin and others, 1915 Arkose Members (Detterman and Hartsock, 1966 Arkose Member is probably a deeper marine sandstone. The Naknek Formation exposed on the coast in Kamishak Bay is younger than the Pomeroy Arkose Member in the Iniskin-Tuxedni region (Imlay and Detterman, 1973 (Jones and Detterman, 1966).…”