Science2010sglobalhigh confidence

A study on carbon spherules concluded that the particles were of natural biological origin and unrelated to either intense wildfires or cosmic impacts.

Notes on verification

Confirmed by peer-reviewed study (Scott et al. 2010, Geophysical Research Letters) identifying carbon spherules as fungal sclerotia, contradicting both wildfire and impact hypotheses. Multiple independent sources corroborate. [tier=gold indep_score=0.867 clusters=3 claim_tier=notable]

Sources