ACID CHARACTER OF ARCHEAN OCEAN WATERS REVEALED BY 3.3-GA-OLD FERRUGINOUS CHERT COMPOSITIONS, WESTERN-AUSTRALIA

Authors
SUGISAKI R HORIUCHI Y SUGITANI K ADACHI M
Citation
R. Sugisaki et al., ACID CHARACTER OF ARCHEAN OCEAN WATERS REVEALED BY 3.3-GA-OLD FERRUGINOUS CHERT COMPOSITIONS, WESTERN-AUSTRALIA, Proceedings of the Japan Academy. Series B Physical and biological sciences, 71(6), 1995, pp. 170-174
Citations number
33
Categorie Soggetti
Multidisciplinary Sciences",Biology
Journal title
Proceedings of the Japan Academy. Series B Physical and biological sciences → ACNP
ISSN journal
03862208
Volume
71
Issue
6
Year of publication
1995
Pages
170 - 174
Database
ISI
SICI code
0386-2208(1995)71:6<170:ACOAOW>2.0.ZU;2-P
Abstract
Comparative inspection of Archean ferruginous cherts with Phanerozoic cherts shows that the former precipitated from acid-water hydrothermal ly supplied during intensive early Precambrian volcanism. The pH of th e water is inferred to have been around 4 where Al dissolves, and Ti a nd Zr do not. The peculiar geochemical environment seems to have been widespread in Archean to early Proterozoic greenstone basins when trem endous volume of banded iron formation (BIF) formed. This suggests tha t the acid seas were neutralized after the BIF deposition probably dur ing the middle to late Proterozoic; this change of pH in sea water may have promoted the deposition of carbonate rocks.