Excerpt: Deep Earth Genesis

Natural History, Dec, 1998 by Thomas Gold

Thomas Gold, founder of and professor emeritus at the Cornell Center for Radiophysics and Space Research, believes that earth's subsurface realm and its inhabitants constitute what he calls the "deep hot biosphere." This is a large region within the earth's crust, deeper than we can drill: the source of earthquakes and a place of vast reservoirs of petroleum, certain metal ores, microbes--and the chemical energy that created life's beginning. Gold, whom Stephen Jay Gould has called "one of America's most iconoclastic scientists," has made major contributions to our understanding of the mechanism of mammalian hearing, the nature of pulsars, and an extraordinary range of other scientific phenomena. One of Gold's controversial ideas is that natural gas and oil originated not from biological deposits but from relics of the material out of which the earth condensed.

From The Deep Hot Biosphere, by Thomas Gold. Copyright 1999 by Thomas Gold. Reprinted by permission of Copernicus, an imprint of Springer-Verlag.

New ideas in science are not right just because they are new. Nor are old ideas wrong just because they are old. A critical attitude is clearly required of every seeker of truth. But one must be as critical of the old ideas as of the new. Whenever the established ideas are accepted uncritically and conflicting new evidence is brushed aside or not even reported because it does not fit, that particular science is in deep trouble. This has happened quite often in several fields. In geology, for example, a person who thought that continents or parts of continents might have moved in the past was ridiculed before 1960, despite the existence of good evidence from magnetic rock measurements. After 1965 anyone who did not believe in such movement was again a subject of ridicule. In petroleum geology, the massive and persuasive evidence for a deep origin of the fluids is still treated with disdain and cannot be published in certain journals.

Carbon and hydrogen can form a great variety of molecules that have different ratios of carbon to hydrogen and different molecular geometries, and all are called hydrocarbons. At the temperatures and pressures on or near the earth's surface, some hydrocarbons are solid (coal), some are liquid (crude oil), and some are in the vapor state (natural gas, which is predominantly methane). Liquid and gaseous hydrocarbons are commonly called petroleum, which exhibits great variation in the proportions of hydrocarbon molecules. Petroleum also has unifying features' that suggest a similar mode of generation. How, then, is petroleum formed?

At the present time, most petroleum geologists outside the former Soviet Union would say that the question has been completely answered--that deposits of biological debris, reworked by geological processes, account for all natural petroleum. Elevated temperatures (but not elevated to volcanic levels) and elevated pressures prevailing at depth will, given sufficient time, perform this feat of alchemy, transforming the remains of surface life buried within sediments--or so we are told. Petroleum is therefore regarded as "fossil fuel." Yet the assemblage of widely accepted facts on petroleum chemistries and their geographical and geological occurrences, considered as a whole, does not support a preference for this standard solution.

The abiogenic theory, the alternative explanation that I favor, holds that hydrocarbons were a component of the material that formed the earth, through accretion of solids, some 4.5 trillion years ago. With increasing internal heat, liquids and gases were liberated, and because they were less dense than the rocks, buoyancy forces drove them upward. In favorable conditions, the upward journey from the regions of origin would be dammed temporarily in porous rocks at depths that our drills can reach, and from which we then derive commercial petroleum.

The abiogenic theory of petroleum formation depends on the truth of five underlying assumptions. First, hydrocarbons, or compounds that could have been converted into hydrocarbons at the intense pressures of the earth's depths, must have been a common constituent of the primordial materials out of which the earth was formed. Second, in the four and a half trillion years since the earth accreted, the primordial hydrocarbons must not subsequently have become dissociated and fully oxidized to carbon dioxide and water by exposure to the significant amounts of oxygen bound in the rocks of the earth's crust. Third, hydrocarbons must be chemically stable at the combinations of high temperature and pressure that prevail deep within the earth. Fourth, hydrocarbon fluids must have found or created suitable pores in which to exist at depth, and through which to travel in their journey upward, driven by buoyancy forces due to their low density compared with that of the rocks. Fifth and finally, a source of hydrocarbons must still exist at great depth. Can these five assumptions all be valid?