stylistic:style_transfer, stylistic:tone
Early Furongian

Continued erosion of the deeper levels of the Gondwanan mountain belts led to a peak in Sr/ Sr and linked positive δ C and δ S excursions, known as the Steptoean positive carbon isotope excursion (SPICE). 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. This increase in the extent of anoxic seafloor conditions led to the extinction of the marjumiid and damesellid trilobites, whilst the increase in oxygen levels that followed helped drive the radiation of plankton.

Sr/ 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.