Sicilian serpentinite xenoliths containing abiotic organics with nanodiamond clusters as key model for prebiotic processes  

作　　者：Sergei K.Simakov Vittorio Scribano Nikolai N.Mel’Nik Germana Barone 

机构地区：[1]LLC“ADAMANT”Skolkovo Participant,Tikhoretsky 10/1-61,St.Petersburg,194064,Russia [2]Department of Biological,Geological and Environmental Sciences,University of Catania,Corso Italia 55-I-95129 Catania,Italy [3]Lebedev Physics Institute,Russian Academy of Sciences,Leninsky Pr.53,Moscow,119991,Russia

出　　处：《Geoscience Frontiers》2021年第1期255-263,共9页地学前缘（英文版）

摘　　要：Rock fragments from the deepest parts of a buried hydrothermal system belonging to the Mesozoic Tethys Ocean entered as xenoliths in a Miocenic diatreme,hence brought to the surface,in the Hyblean Plateau(Sicily).Some xenoliths 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 up established hypotheses that diamond surfaces are suitable catalytic platforms stimulating the assemblage of complex bio-organic molecules relevant to the emergence of life on Earth.The appearance of bio-organic molecules under primitive Earth conditions is one of the major unsolved questions on the origin of life.Here we report new micro-Raman spectra on blebs of abiotic organic matter from a selected xenolith.Diamond bands were related to hydrogenated nanocrystalline diamonds,with size of nearly 1-1.6 nm,formed from organics at low pressures and temperatures.In particular,diamond surfaces can give rise to crystalline interfacial water layers that may have played a fundamental role in the early biosphere evolution as a good medium for rapidly transporting positive charges in the form of hydrated protons.Nowadays,proton gradients in alkaline hydrothermal vents along oceanic ridges are generally viewed as key pre-biotic factors.In general,serpentinites span the entire geological record,including prebiotic times.These hydrous ultramafic rocks often display evidence of abiotic carbon species,both organic and inorganic,including nanodiamonds,being also capable to give rise to chemiosmotic processes and proton gradients necessary to the organisms,such as the"Last Universal Common Ancestor"(LUCA),in the prebiotic Earth.

关 键 词：Hydrothermal systems Nanocarbons Sulfides Fr-t synthesis Abiogenesis LUCA Sicily MICRO-RAMAN 

分 类 号：P588.248[天文地球—岩石学] P534.5[天文地球—地质学]