ANAHITA, DEEV JAHI, AND AMORDAAD: THREE OCEANS OF THE PERMIAN - TRIASSIC BOUNDARY

Geochemical signatures and sedimentological characteristics of the Permian – Triassic boundary (PTB) strata in Iran, China, and Europe suggest that three types of oceans existed during this time period. Bulk-rock carbon and oxygen isotopic values remain relatively invariant in the Upper Permian strata, both declining linearly toward the PTB, but increase in Early Triassic. The Upper Permian strata consist of carbonates deposited under normal marine conditions at a high rate of sedimentation indicative of high biological productivity in a healthy ocean. The uppermost Permian strata encompass the biological devastation and display a very slow rate of sedimentation suggestive of disruption in carbonate production. The lowermost Triassic layers contain enigmatic features consisting of abiotic and microbial carbonates precipitated at a high rate of sedimentation under unusual conditions.

Sedimentological and geochemical characteristics of the PTB strata can be related to the existence of three oceans with distinct seawater compositions. The Anahita (the Goddess of water and fertility in Persian mythology) Ocean with its life-nurturing seawater occurred in the Upper Permian before the mass killing began, promoting high diversity, normal marine sedimentation, and high productivity.

The Deev Jahi (a female deeman and killer of all life form in Persian mythology) Ocean operated during the uppermost Permian. It formed by massive injection of methane into the ocean. Its seawater was hot, bubbly, and burning, causing the biological catastrophe at PTB. The Deeve Jahi Ocean became highly acidic at the PTB (the Acid Bath Ocean) when dissolved CO2 concentrations became very high resulting is platform dissolution and slow rate of carbonate precipitation. Deev Jahi Ocean was terminated when the generation of CO2 ceased.

The Amordaad (the Goddess of immortality in Persian mythology) Ocean operated during Early Triassic. It was highly supersaturated with respect to calcium carbonate leading to precipitation of enigmatic cement – microbial carbonates. The Amordaad Ocean was hostile, but its seawater was sufficiently nurturing to prevent the total demise of life in the ocean.