Towards a carbon isotope stratigraphy of the Cambrian System: potential of the Great Basin succession

Abstract

The Cambrian spans a time of major biosphere change, during which the major invertebrate groups appeared and radiated.

The Furongian (late Cambrian) Steptoean Positive Carbon Isotope Excursion (SPICE) in Avalonia

“…More recently, the same positive Carbon Isotope Excursion (CIE) has been identified in organic-rich mudstones of the Alum Shale Formation in southern Sweden, where δ 13 C org peak values are around -28‰ (with a maximum amplitude of around 2‰) (Ahlberg et al, 2009). This CIE, first recognised in the late Cambrian of North America by Brasier (1993) and confirmed as a global CIE by Saltzman et al (1995), is termed the Steptoean Positive Carbon Isotope Excursion (SPICE) (Saltzman et al, 1998). We report here the occurrence of the SPICE in the Cambrian of central England, the first record in an Avalonian succession.…”

The Henson Gletscher Formation, North Greenland, and its bearing on the global Cambrian Series 2–Series 3 boundary

“…Clearly, a satisfactory GSSP will need to be based on paleontological data. Carbon isotopes may be useful for delimiting the Ediacaran-Cambrian boundary interval and the earliest Cambrian period for which several positive carbon isotope excursions can be detected in various regions (Banerjee et al 1994;Brasier 1985Brasier , 1991Brasier , 1992Brasier , 1994Brasier et al 1990Brasier et al , 1992Brasier et al , 1993Brasier et al , 1994aBrasier et al , 1994bBrasier & Sukhov 1998;Derry et al 1994). Nevertheless, such distinct excursions are largely absent (or not yet recognized) for the second half of the Early Cambrian and the early Middle Cambrian, although several regional studies seem to promise useful results (e.g.…”

Significant carbon isotope excursions in the Cambrian and their implications for global correlations

“…It was first reported at the Cambrian Steptoean Stage in the Great Basin of Western America [59]. Up till now, it has been documented in the basal strata of Paibian Stage (Furongian Series) developed in different sedimentary environments in Kazakhstan [15], China [50,53,60], Siberia [61], North America [55,59,62], Australia [63,64], South America [65], Europe [66] and Antarctica [67] (Figure 1). Therefore, it is considered to be a global Cambrian carbon cycle fluctuation and a paleoceanographic event that confirms intercontinental correlations between different biogeographic realms (Figures 1 and 5).…”

“…Consequentially, a high burial ratio of organic carbon rich in 12 C would be induced, which, in turn, inevitably results in the positive  13 C excursion. The opinion that the f org increases seems to be doubted, because there Figure 5 Intercontinental correlations of "SPICE" events documented at Great Basin [59] and Nevada [15] in USA, Hunan Province in China [60], Kyrshabakty River in Kazakhstan [60], Queensland in Australia [60] and Kulyumbe River in northwestern Siberia Platform [61] respectively. The  13 C excursions are all with biostratigraphic constraints.…”