Uppermost Cambrian carbon chemostratigraphy: the HERB and undocumented TOCE events are not synonymous. (16th August 2020)

• Record Type: Journal Article
• Authors: Landing, Ed; Ripperdan, Robert L.; Geyer, Gerd
• Is Part Of: Geological magazine. Volume 157:Number 8(2020)
• Page Start: 1373
• Page End: 1377
• Publication Date: 2020-08-16
• Subjects: Cambrian, -- carbon isotopes, -- HERB excursion, -- TOCE; Geology -- Periodicals; 551.05
• DOI: 10.1017/S0016756820000382
• Languages: English
• ISSNs: 0016-7568

Abstract

Abstract: Chemostratigraphic units require consistent definitions and unambiguous names. So-called TOCE (Top of Cambrian Excursion) is used as an uppermost Cambrian δ 13 Ccarb negative excursion although it was proposed without documentation, is ambiguously defined, and variably correlated into four Laurentian trilobite zones. TOCE, a nihilartikel, is regularly substituted to the exclusion of the earlier named, precisely documented and geochronologically older HERB (Hellnmaria-Red Tops Boundary) Event. HERB allows late Cambrian global correlation; its onset is close to the lowest occurrence of the conodont Eoconodontus notchpeakensis at the base of a proposed replacement (Lawsonian Stage) of Cambrian Stage 10. TOCE must be retired from use and abandoned as a synonym of the HERB Event.