WAS THE EARTH AN ICE GLOBE BEFORE THE GERM OF LIFE?
It is deemed that early earth was really hot: in particular, water temperature in the ocean gained 85 degrees centigrade. However, the analysis of South African rock refuse formed in Archean period 3.5 billion years ago, testified that in those remote time the Planet could be ice glazed on the contrary and thereby life originated…
The theory of "Snowball Earth" suggested that more than 700 million years ago our planet was a gigantic snowball: the ice crust laid over it from poles to equator. This mighty Great Ice Age had been lasting for decades of million years.
But, as soon as this theory appeared, it was declined momentarily as impossible idea. Nevertheless, more and more evidences arise in its favor currently…
Martin de Vite from the Nelson Mandela University in Port Elizabeth (South Africa) and his colleagues were busy with the research study of Greenstone vein system massive formed in the latitude of 20 to 30 degrees. The measurement of oxygen isotopes balance inside of these roaches testified that the ocean had been frozen in the period of their formation.
It differs from the results of previous reconnaissance, according to which the temperature was much higher in Archean. The scholars from the Mandela University assumed that their precursors came up with different roach, which had been subject to impact of hydro-thermal vents (this is a definition of hot well springs flapping from beneath the ocean bottom).
De Vite and his colleague Harald Furns from the Bergen University, in their turn, made the investigation of oceanic sediment free from influence of hydro-thermal vents. They succeeded in finding out proof of lime hydrous sulfate formation, which is feasible only in abyssal areas where cold water is present.
To avoid mistakes in findings, the experts examined junior sediments formed at the less ocean deep and above the sea level too. Small banded silt stones with distinct pebble dissemination were found over there. According to expert opinion, they look like bottom lamination developing, as a rule, in shallow parts of icebound ocean.
The academic community, of course, couldn’t accept conclusions of De Vite’s team without reserve. Some researchers claimed that such a mineral like gypsum can grow even at a temperature of water about 80 degrees. Meanwhile, De Vite is convinced that, under such high temperatures, gypsum comes into existence only at shallow water areas where water evaporation takes place, but the gypsum crystals studied by his group took their shape at a depth of 2-4 kilometers.
By the way, shortly before De Vite’s survey another science team exploring oxygen isotopes in Greenstone vein system, reasoned that in Archean era water was not hot nor icy but comparatively cool like in contemporary tropic oceans…
So, what about the germ of life? We take for gospel that it emerged from water, but what kind of water? The fact is that certain probes denote: life forms could begin to take off in solid water too, because constitutive organic compounds keep stable structure alive even with pretty low temperatures.
Even more, the cold is really quite useful for some organic molecules being crucial for the germ of life since it makes them become more concentrated.
The laboratory test confirms this hypothesis: the research testifies that "ice conditions" amplify synthesis of certain important molecules and inhibit decay process of other labile molecules, which typically starts immediately after their genesis.
And there is one more "irresistible" proof of "snowball" hypothesis. In July last year, a team of geologists led by Paul Hoffman examined lithic concrements discovered in 90s of the past century in the territory of Namib Desert. There was a time, when roaches were situated not in the middle of burning sandy desert but at the ocean bottom.
It turned out that these stones are similar in composition to those ones, which come up at the bottom of the Arctic Ocean. Thus, oversize Great Ice Age was, anyway, massive enough and involved practically the whole area of the planet.