Evidence for 15 m.y. of continuous deep-sea biogenic siliceous sedimentation in early Paleozoic oceans

Citation
Tj. Tolmacheva et al., Evidence for 15 m.y. of continuous deep-sea biogenic siliceous sedimentation in early Paleozoic oceans, GEOLOGY, 29(8), 2001, pp. 755-758
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
GEOLOGY
ISSN journal
0091-7613 → ACNP
Volume
29
Issue
8
Year of publication
2001
Pages
755 - 758
Database
ISI
SICI code
0091-7613(200108)29:8<755:EF1MOC>2.0.ZU;2-E
Abstract
Upper Cambrian to Lower Ordovician radiolarites (alternations of ribbon-ban ded radiolarian cherts and siliceous shales) from Kazakhstan are dated accu rately by means of conodonts. They represent the only known continuous sequ ence of abyssal deposits across the Cambrian-Ordovician boundary. The radio larites are associated with remnants of oceanic crust (ophiolites) and form the oldest-known radiolarian ooze accumulations, which presumably formed i n equatorial paleolatitudes. The Cambrian cherts contain clusters of conodo nts (especially paraconodonts) that are very poorly known at present, despi te their potential for improved understanding of conodont community structu re and paleoecology.