TY - JOUR

T1 - New Data on Biostratigraphy of the Middle Cambrian Section at the Khorbusuonka River, Northeastern Siberian Platform

AU - Korovnikov, I. V.

AU - Tokarev, D. A.

PY - 2018/11/1

Y1 - 2018/11/1

N2 - The aggregated section of Middle Cambrian at the Khorbusuonka River, northeastern Siberian Platform, is described. The aggregated sequence is compiled on the basis of investigations at four bank outcrops. The findings of trilobites at different stratigraphic levels allowed us to identify the intervals comparable to regional zones of the Amgan and Mayan stages (Middle Cambrian). New findings and analysis of stratigraphic distribution of trilobites helped to specify the position of the Middle Cambrian lower boundary. The lower boundary of the Mayan Stage is drawn by the first appearance of Corynexochus perforatus in the section, 9 m from the base of the Yunkyulyabit-Yuryakh Formation. Trilobites of Cyclolorenzella sp. and Kuraspis sp. found in the upper Tyussala Formation are characteristic of the boundary layers of the Middle and Upper Cambrian. It was supposed earlier that the Upper Cambrian part of the sequence began in the overlying Lapar Formation; however, the aforementioned findings suggest that the Middle Cambrian lower boundary can be located within the limits of the upper Tyussala Formation.

AB - The aggregated section of Middle Cambrian at the Khorbusuonka River, northeastern Siberian Platform, is described. The aggregated sequence is compiled on the basis of investigations at four bank outcrops. The findings of trilobites at different stratigraphic levels allowed us to identify the intervals comparable to regional zones of the Amgan and Mayan stages (Middle Cambrian). New findings and analysis of stratigraphic distribution of trilobites helped to specify the position of the Middle Cambrian lower boundary. The lower boundary of the Mayan Stage is drawn by the first appearance of Corynexochus perforatus in the section, 9 m from the base of the Yunkyulyabit-Yuryakh Formation. Trilobites of Cyclolorenzella sp. and Kuraspis sp. found in the upper Tyussala Formation are characteristic of the boundary layers of the Middle and Upper Cambrian. It was supposed earlier that the Upper Cambrian part of the sequence began in the overlying Lapar Formation; however, the aforementioned findings suggest that the Middle Cambrian lower boundary can be located within the limits of the upper Tyussala Formation.

KW - stratigraphy

KW - Middle Cambrian

KW - trilobites

KW - Siberian Platform

KW - Khorbusuonka River

KW - KHORBOSUONKA RIVER

UR - http://www.scopus.com/inward/record.url?scp=85061564901&partnerID=8YFLogxK

U2 - 10.1134/S0869593818060035

DO - 10.1134/S0869593818060035

M3 - Article

VL - 26

SP - 599

EP - 610

JO - Stratigraphy and Geological Correlation

JF - Stratigraphy and Geological Correlation

SN - 0869-5938

IS - 6

ER -