Linking the Jehol Biota evolution to the Early Cretaceous volcanism
during the North China craton destruction: insights from F, Cl, S, and P
Abstract
The Early Cretaceous Jehol Biota evolution has remarkable spatiotemporal
correlation with the destruction of the North China craton though the
coupling mechanism remains enigmatic. The craton destruction was
accompanied by intense magmatic activity and the released volatiles and
nutrients might have had climatic and environmental impacts on the
biotic evolution. In this study, we investigated the mentioned
hypothetical causal link by determining concentrations and total
emissions of volatile elements (S, F, Cl) and bulk-rock P contents of
volcanic rocks that were erupted during the pre-flourishing, flourishing
and post-flourishing stages of the Jehol Biota. Our results show that
the volcanism near the flourishing stage has lower S (1083-2370 ppm), Cl
(1277-5608 ppm) and higher P2O5 contents
(0.48-0.84 wt.%) than that in non-flourishing stages with S of
1991-3288 ppm, Cl of 7915-12315 ppm and
P2O5 of 0.17-0.23 wt.%. Fluorine
contents in the three stages vary from 893 to 3746 ppm. The total
volatile emissions are minor in the flourishing stage (3.6-6.6 Gt S,
2.2-4.6 Gt Cl and 2.1-4.0 Gt F) but elevated in the non-flourishing
stages (1-690 Gt S, 4-934 Gt Cl and 1-308 Gt F). Our data suggest that
regional climatic and environmental impacts of volcanism in the
non-flourishing stages probably hindered the species diversification.
The high P flux released from lithospheric mantle-derived lavas during
the peak time of craton destruction might enhance primary productivity
and contribute to the flourishing of the Jehol Biota. Our study provides
insights into the relationship between the biosphere and deep geodynamic
processes driven by volcanism.