Oxygen and carbon isotope stratigraphy of early cambrian carbonates in southeastern Newfoundland and England
By: Brasier, M.D.
Contributor(s): Anderson, M.M | Corfield, R.M.
Material type: ArticleDescription: 265-279p ; Illustration.Subject(s): Oxygen isotope stratigraphy - Early cambrian carbonates - Southeastern Newfoundland and England | Carbon isotope stratigraphy - Early cambrian carbonates - Southeastern Newfoundland and England | Chemostratigraphy - Newfoundland and England In: Geological magazine : Vol. 129 Iss. 1-6 Year. 1992Summary: Abstract Carbonate rocks have been sampled through predominantly siliciclastic sediments above the Precambrian-Cambrian global stratotype level in southeastern Newfoundland to assess their potential for oxygen and carbon isotope stratigraphy. Comparable successions were sampled at Nuneaton and Comley in England. Greatly depleted δ18O signals are attributed to widespread thermal alteration during deep burial and granitic intrusion, including within the stratotype region. Carbon isotope ratios appear to have been less affected and these are described from nine sections. A provisional, composite δ13C curve is based on non-ferroan, pink nodular and bedded micrites. Several δ13C excursions occur in the fossiliferous Bonavista Group and allow the position of the Tommotian-Atdabanian boundary to be identified. Chemostratigraphic correlation of the new Precambrian-Cambrian boundary stratotype may, however, prove difficult because of the lack of suitable, well-preserved carbonates. The search must begin for a comparable reference section allowing global correlation of the boundary level using chemostratigraphy as well as biostratigraphy.Item type | Current location | Collection | Call number | Status | Date due | Barcode |
---|---|---|---|---|---|---|
Article | Library and Information Centre Periodical Section | Bound Journal Collection | Not for loan | 002537_30 | ||
Serials/Scientific Journal | Library and Information Centre Periodical Section | Bound Journal Collection | 550 GEO (Browse shelf) | Available | 002537 |
Abstract
Carbonate rocks have been sampled through predominantly siliciclastic sediments above the Precambrian-Cambrian global stratotype level in southeastern Newfoundland to assess their potential for oxygen and carbon isotope stratigraphy. Comparable successions were sampled at Nuneaton and Comley in England. Greatly depleted δ18O signals are attributed to widespread thermal alteration during deep burial and granitic intrusion, including within the stratotype region. Carbon isotope ratios appear to have been less affected and these are described from nine sections. A provisional, composite δ13C curve is based on non-ferroan, pink nodular and bedded micrites. Several δ13C excursions occur in the fossiliferous Bonavista Group and allow the position of the Tommotian-Atdabanian boundary to be identified. Chemostratigraphic correlation of the new Precambrian-Cambrian boundary stratotype may, however, prove difficult because of the lack of suitable, well-preserved carbonates. The search must begin for a comparable reference section allowing global correlation of the boundary level using chemostratigraphy as well as biostratigraphy.
There are no comments for this item.