Steptoean positive carbon isotope excursion


The Steptoean Positive Carbon Isotope Excursion was a geological event which occurred about 500 million years ago at the end of the Cambrian Period. The SPICE event was a sudden reversal of the anoxia that had steadily spread throughout the oceans during the Cambrian which also affected the atmosphere. After the SPICE event, oxygen levels recovered and levels in the atmosphere may have risen as high as 30%, higher than the 21% of the atmosphere that prevails today. The sudden increase in oxygen led to an explosion of life across the globe. A recent study shows that the SPICE may be linked to Cambrian true polar wander.