Carbon isotopic data from the Selinde section in the southeastern part of the Siberian platform area are correlated with the reference isotopic profile from the Lower Cambrian stratotype sections of the Lena Aldan region, but also show additional d13C excursions unrecognized there. The chemostratigraphic correlation suggests that the geological and fossil record of the lower Pestrotsvet Formation in the Selinde section has a deeper history than the stratotype region. This conclusion is important for both constraining the age of the earliest Cambrian marine transgression on the Siberian platform and providing a clearer understanding of the pace and order of early Cambrian geochemical and biological events.

The paper deals with a section (57°23'38N; 132°42'25E) situated in the uppermost reaches of the Selinde River, a small right tributary of the Uchur River, in the southeastern part of the Siberian platform. The outcrop is at the southern slope of the Ket-Kap Range, 13 km SE of the town Mar-Kyuel'.

Supplement to: Kouchinsky, Artem; Bengtson, Stefan; Pavlov, Vladimir; Runnegar, Bruce; Val'kov, Anatolij K; Young, Edward (2005): Pre-Tommotian age of the lower Pestrotsvet Formation in the Selinde section on the Siberian platform: carbon isotopic evidence. Geological Magazine, 142(4), 319-325