Editing Cambrian (section)

==== Early Furongian ====
Continued erosion of the deeper levels of the Gondwanan mountain belts led to a peak in <sup>87</sup>Sr/<sup>86</sup>Sr and linked positive δ<sup>13</sup>C and δ<sup>34</sup>S excursions, known as the [[Steptoean positive carbon isotope excursion]] (SPICE).<ref name="Myrow-2024" /> This indicates similar geochemical conditions to Stages 2 and 3 of the early Cambrian existed, with the expansion of seafloor anoxia enhancing the burial rates of organic matter and pyrite.<ref name="Zhang-2020" /> This increase in the extent of anoxic seafloor conditions led to the extinction of the marjumiid and [[Damesellidae|damesellid]] trilobites, whilst the increase in oxygen levels that followed helped drive the radiation of plankton.<ref name="Peng-2020" /><ref name="Pruss-2024" />

<sup>87</sup>Sr/<sup>86</sup>Sr fell sharply near the top of the Jiangshanian Stage, and through Stage 10 as the Gondwanan mountains were eroded down and rates of weathering decreased.<ref name="Peng-2020" /><ref name="Zhang-2020" />