Editing Cambrian (section)

==== Cambrian Stage 4 to early Miaolingian ====
The beginning of the eruptions of the Kalkarindji LIP basalts during Stage 4 and the early Miaolingian released large quantities of carbon dioxide, methane and sulphur dioxide into the atmosphere. The changes these wrought are reflected by three large and rapid δ<sup>13</sup>C excursions. Increased temperatures led to a global sea level rise that flooded continental shelves and interiors with anoxic waters from the deeper ocean and drowned carbonate platforms of archaeocyathan reefs, resulting in the widespread accumulation of black organic-rich shales. Known as the Sinsk anoxic extinction event, this triggered the first major extinction of the Phanerozoic, the 513 – 508 Ma Botoman-Toyonian Extinction (BTE), which included the loss of the archaeocyathids and [[Hyolitha|hyoliths]] and saw a major drop in biodiversity.<ref name="Myrow-2024" /><ref name="He-2019" /> The rise in sea levels is also evidenced by a global decrease in <sup>87</sup>Sr/<sup>86</sup>Sr. The flooding of continental areas decreased the rates of continental weathering, reducing the input of <sup>87</sup>Sr to the oceans and lowering the <sup>87</sup>Sr/<sup>86</sup>Sr of seawater.<ref name="Zhang-2020" /><ref name="Peng-2020" />

The base of the Miaolingian is marked by the Redlichiid–Olenellid extinction carbon isotope event (ROECE), which coincides with the main phase of Kalkarindji volcanism.<ref name="Myrow-2024" />

During the Miaolingian, orogenic events along the Australian-Antarctic margin of Gondwana led to an increase in weathering and an influx of nutrients into the ocean, raising the level of productivity and organic carbon burial. These can be seen in the steady increase in <sup>87</sup>Sr/<sup>86</sup>Sr and δ<sup>13</sup>C.<ref name="Zhang-2020" />