TY - JOUR
T1 - Minimal biomass deposition in banded iron formations inferred from organic matter and clay relationships
AU - Dodd, Matthew S.
AU - Papineau, Dominic
AU - Pirajno, Franco
AU - Wan, Yusheng
AU - Karhu, Juha A.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - The cycling of iron and organic matter (OM) is thought to have been a major biogeochemical cycle in the early ferruginous oceans which contributed to the deposition of banded iron formations (BIF). However, BIF are deficient in OM, which is postulated to be the result of near-complete oxidation of OM during iron reduction. We test this idea by documenting the prevalence of OM in clays within BIF and clays in shales associated with BIF. We find in shales >80% of OM occurs in clays, but <1% occurs in clays within BIF. Instead, in BIF OM occurs with 13C-depleted carbonate and apatite, implying OM oxidation occurred. Conversely, BIF which possess primary clays would be expected to preserve OM in clays, yet this is not seen. This implies OM deposition in silicate-bearing BIF would have been minimal, this consequently stifled iron-cycling and primary productivity through the retention of nutrients in the sediments.
AB - The cycling of iron and organic matter (OM) is thought to have been a major biogeochemical cycle in the early ferruginous oceans which contributed to the deposition of banded iron formations (BIF). However, BIF are deficient in OM, which is postulated to be the result of near-complete oxidation of OM during iron reduction. We test this idea by documenting the prevalence of OM in clays within BIF and clays in shales associated with BIF. We find in shales >80% of OM occurs in clays, but <1% occurs in clays within BIF. Instead, in BIF OM occurs with 13C-depleted carbonate and apatite, implying OM oxidation occurred. Conversely, BIF which possess primary clays would be expected to preserve OM in clays, yet this is not seen. This implies OM deposition in silicate-bearing BIF would have been minimal, this consequently stifled iron-cycling and primary productivity through the retention of nutrients in the sediments.
UR - http://www.scopus.com/inward/record.url?scp=85074363177&partnerID=8YFLogxK
U2 - 10.1038/s41467-019-12975-z
DO - 10.1038/s41467-019-12975-z
M3 - Article
C2 - 31685820
AN - SCOPUS:85074363177
SN - 2041-1723
VL - 10
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 5022
ER -