Comments and Replies on “Model for the origin of the Yakutat block, an accreting terrane in the northern Gulf of Alaska”

TitleComments and Replies on “Model for the origin of the Yakutat block, an accreting terrane in the northern Gulf of Alaska”
Publication TypeJournal Article
Year of Publication1984
AuthorsBruns, TR, Keller, G
JournalGeology
Volume12
Pagination565
Abstract

Wolfe and McCoy assert that Bruns's (1983a) model for the northward migration of the Yakutat block is not supported by foraminiferal or molluscan evidence and is contradicted by paleobotanical evidence. Contrary to this claim, both planktonic and benthic foraminiferal data are consistent with Bruns's model and provide temporal constraints on the northward migration of the Yakutat block, Prince William terrane, and Pacific plate between late early Eocene (50 Ma) and late Eocene to early Oligocene (38-34 Ma; Keller et al., 1984). Our foraminiferal evidence is based on detailed study of material from DSDP cores (Sites 192,183, 178), an exploratory drill hole (Middleton Island Well), dredged rocks from the Gulf of Alaska, and comparison with onshore coeval sediment sequences from California, Oregon, and Washington. We are not aware of a comparable geographic coverage of mollusca or paleobotanical data from well-dated rocks. Wolfe and McCoy have compared our GEOLOGY, September 1984 565 microfossil assemblages with molluscan and floral assemblages that are not coeval, and they try to correlate continental paleoclimates with oceanic paleoenvironments. Even worse, however, is the uncertainty in their dating, which in some cases spans the time during which the Yakutat block would have traveled through one climatic zone and well into another.  PDF

URLhttps://doi.org/10.1130/0091-7613(1984)12<565:caromf>2.0.co;2
DOI10.1130/0091-7613(1984)12<565:caromf>2.0.co;2