Petroleum in space? Ain’t that a gas! – Part 2
The widely accepted view is that petroleum formed from organisms—mostly plants and small marine animals—which accumulated in swamp mud and on river and ocean beds.Over time, the theory holds, the organisms got buried under flowing detritus; and the resulting heat, together with pressure, transformed the organic matter into kerogen.
But as Ker Than reminds Live Science readers, not all scientists accept this “biogenic” model of petroleum formation. Some believe Earth already had more oil than dead organisms has produced.
Russian scientists are the originators and leading exponents of this “abiogenic” explanation—which reportedly date back to the Cold War Era of the 1950s. (The biogenic idea too, may be traced to Russia!)
Abiotic adherents—among whom are also U.S. and European partisans—argue that oil and gas formation does not require organic matter. Nor is it confined to Earth’s crust.
Petroleum, contends the “modern Russian-Ukrainian theory of abyssal, abiotic petroleum origins,” is a “primordial material” erupting from Earth’s mantle—a semi-fluid mass, nearly 3000 km thick.
The mantle lies between Earth’s crust and core. “In this subterranean area,” notes the 21st Century Tech website’s Len Rosen, “… methane forms when iron oxide, calcite and water interact”.
The reactions, Russian scientists and their Western cohorts aver, occur at a depth far below that at which any living organisms have ever existed.In late 2004, for example, Nature News reported on an experiment which scientists at Indiana University, U.S.A., conducted do demonstrate the possibility of deep mantle petroleum synthesis.
The laboratory experiment showed, Nature noted, that methane “is stable at the intense temperatures and pressures found in Earth’s mantle, 100-300 kilometres beneath the surface”.Since that time, drilling has confirmed the existence of deep petroleum deposits, which—some advocates insist—lend further support to the abiogenic theory.
“Until a decade or so ago,” wrote the conservative U.S. commentator, O.R. Adams, Jr., in 2011, “virtually all oil discovered was in the range of 5-10 miles (8 to 16 km) into the crust.
“Yet recently,” he continued, referring to the famous Dnieper–Donets Basin Province, in Russia and Ukraine, “the Russians have discovered major oil pockets as far down as 40 miles (64 km)”.More germane, is the second line of evidence on which the abiotic argument rests: That being the presence of methane and other hydrocarbons beyond Earth.
Both methane and ethane, for instance, have been observed spectrally, on solar system bodies and even in the interstellar medium—where no biological processes are known to be at work.
Methane (CH4), in particular, wrote Sushil K. Atreya, in Atlantic Monthly, “is abundant on the giant planets—Jupiter, Saturn, Uranus and Neptune…”The most intense scientific scrutiny though, has been focused on Mars and Saturn’s mammoth moon, Titan. The latter is loaded with methane, and its weightier chemical stablemate, ethane, in liquid form.
NASA estimates that Earth’s natural gas reserves could provide “300 times the amount of energy the …(U.S.A.) uses annually for residential heating, cooling and lighting”.
Yet, it speculates, “Dozens of Titan’s lakes individually have the equivalent of at least this much energy in the form of methane and ethane”. Atreya makes reference to a scientific model, which attributes the natural gas bonanza on Saturn’s icy moon to a subsurface ocean, 200-to-300 km deep.
He surmises that “Reactions between the water and…rock [at the ocean floor]…liberated hydrogen gas, which in turn…reacted with carbon dioxide, carbon monoxide, carbon grains (etc.)…”.This process, Atreya believes, may explain Titan’s observed methane abundance.
To be continued.