Bromine content of salts from DSDP Hole 13-134, Mediterranean Sea (Table 1)

A deep-sea drilling cruise to the Mediterranean in late 1970 discovered the presence of an extensive evaporite deposit under the Mediterranean seabed. The deposit includes dolomite, anhydrite, gypsum, halite, and more soluble salts and covers an area more than 10**6 km 2. The origin of the evaporites has been interpreted as the product of desiccation, when the Mediterranean was isolated from the Atlantic during the Late Miocene Messinian stage, 5-7 million years ago. The desiccation led to a total destruction of pre-Messinian marine faunas and permitted the development of oligohaline and euryhaline faunas in the Mediterranean region. The circum-Mediterranean lands became arid and forests were replaced by savannas and steppes. Large-scale migrations, especially of grazing animals, may have been the consequence of such a drastic change in geography and in ecology

Gaia and the Mediterranean Sea

The Earth is a self-organizing system liking a living organism. Lovelock proposed Gaia as a metaphor to designate the check and balance ofterrestrial temperatures: the Earth is never too hot so that the ocean could boil, and the Earth is never too cold that the ocean could freeze from top to bottom. Hsü proposed that Gaia is endothermic because the life on Earth has been alternate successions of air-conditioners and heaters which evolved and deactivate or reinforce the terrestial greenhouse of carbon dioxide in atmosphere. When Earth was heating up too much, the air-conditioneers, such as anaerobic bacteria, cyanobacteria, skeletal organisms and trees, and finally calcareous plankton, went to work to bring the terrestrial temperature down. When the Earth was freezing at times of continental glaciation, heaters went to work, such as methanogenic bacteria, Ediacaran faunas, tundra and desert plants, and now Homo sapiens. Gaia has to have other organs to keep the self-organizing system vital. This paper presents a postulate that the Miocene Mediterranean Sea acted as Gaia´s kidney. The steady influx of dissolved ions and debris into the ocean causes inevitable increase of ocean´s salinity. The fossil and geochemicl records indicate that the ocean has never been too saline nor too brackish for the survival of normal marine organisms: the salinity ranged from about 32 to 36 pro mil during the last billion years. Ocean-drilling cruises to the Mediterranean discovered a very large salt formation, deposited during some 5 million years ago when the Mediterranean dried up. A study of the geochemical balance of the oceans indicates that the deposition of very large salt bodies in isolated basins such as the Miocene Mediterranean every 100 million years or so. The saline giants have the function of Gaia´s kidney. With periodical removals of the salt ions and the heavy metals from seawater, the world´s ocean have been rendered forever habitable. Gaia has to have a kidney. The desiccation of the Mediterranean is the evidence of a functioning kidney. Earlier kidney functions were performed during the deposition of the Cretaceous (South Atlantic), Jurassic (Gulf of Mexico), Permo-Triassic (Europe), Devonian (Canada),.Cambrian/Precambrian (Gondwana) saline giants.No disponible

(Table 1) Chemical composition of Mediterranean halite from DSDP Hole 13-134

Bromine content of a 15 cm halite core from Deep Sea Drilling Project Leg XIII Hole 134 was analyzed at 1.5 cm intervals. The Br varies from 140 to 254 ppm, and three maxima were found to coincide with three postulated horizons of desiccation. The Br profile confirms the interpretation from sedimentologic evidence that Mediterranean salts were deposited in a desiccating basin