Sicilian serpentinite xenolihs conaining abioic organics wih nanodiamond clusers ans key model for prebioic processes

• 作者: Sergei K.Simakov Vittorio Scribano Nikolai N.Mel'Nik Germana Barone
• 来源期刊: 地学前缘（英文版）
• 年，卷（期）: 2021,（1）
• 所属期刊栏目: Research Paper
• 页码范围: 255-263
• 页数: 9页
• 语种: 英文

摘要

Rock fragments from the deepest parts of a buried hydrothermal system belonging to the Mesozoic Tethys Oceanentered as xenoliths in a Miocenic diatreme. hence brought to the surface, in the Hyblean Plateau (Sicily). Somexenoliths consist of strongly serpentinized ultramafic rocks bearing blebs of abiotic organic matter, where clusters of amorphous carbon nanoparticles, including nanodiamonds, are immersed. Such an occurrence conjures upestablished hypotheses that diamond surfaces are suitable catalytic platforms stimulating the assemblage ofcomplex bio-organic molecules relevant to the emergence of life on Earth. The appearance of bio-organic mol-ecules under primitive Earth conditions is one of the maj or unsolved questions on the origin of life. Here we reportnew micro-Raman spectra on blebs of abiotic organic matter from a selected xenolith. Diamond bands wererelated to hydrogenated nanocrystalline diamonds, with size of nearly 1-1.6 nm, formed from organics at lowpressures and temperatures. In particular. diamond surfaces can give rise to crystalline interfacial water layersthat may have played a fundamental role in the early biosphere evolution as a good medium for rapidly trans-porting positive charges in the form of hydrated protons. Nowadays, proton gradients in alkaline hydrothermalvents along oceanic ridges are generally viewed as key pre-biotic factors. In general, serpentinites span the entiregeological record, including prebiotic times. These hydrous ultramafic rocks often display evidence of abioticcarbon species, both organic and inorganic, including nanodiamonds, being also capable to give rise to chemi-osmotic processes and proton gradients necessary to the organisms, such as the "Last Universal CommonAncestor" (LUCA), in the prebiotic Earth.