Fig.1. Proposed relationships in the equatorial Early Paleozoic among shellyand graptolite biofacies, shelly and black shale lithofacies, and chemical oceanography (Modified from Berry et al., 1987). Chemical model (Redfield et al., 1963, p. 46) uses modern surface values in the ETP (Anderson, 1982), but with no deep ventilation.
A. Conditions for warm climates and high stands of sealevel.
B. Conditions for cold climates and low stands of sealevel.