Water-rock Interaction Xiii || ~UPD~
Water-rock Interaction Xiii || >>> https://urloso.com/2t8byY
focussed on water-rock interaction, which has wide applications for hyrogeochemists, soil scientists, petrologists, economic geologists, and environment geologists in academia, industry, and applied laboratories
Organic molecules found in a meteorite that hurtled to Earth from Mars were synthesized during interactions between water and rocks that occurred on the Red Planet about 4 billion years ago, according to an analysis to be published this week in Science.
They found evidence of water-rock interactions similar to those that happen on Earth. The samples indicate that the Martian rocks experienced two important geochemical processes. One, called serpentinization, occurs when iron- or magnesium-rich igneous rocks chemically interact with circulating water, changing their mineralogy and producing hydrogen in the process. The other, called carbonization, involves interaction between rocks and slightly acidic water containing dissolved carbon dioxide and results in the formation of carbonate minerals.
It is unclear whether these processes were induced by surrounding aqueous conditions simultaneously or subsequently, but the evidence indicates that the interactions between water and rocks did not occur over a prolonged period. What is evident, however, is that the reactions produced organic material from the reduction of carbon dioxide.
14C is probably the most important radio-isotopic tool for dating deep groundwater, despite serious problems related to potential interactions of DIC species with the carbonate minerals and possible contributions of 14C-free deep CO2. Such contributions are quite common in geothermal waters, which may have a very low 14C content even if they contain tritium. 14C is most useful for dating waters and organic material in the range of 1000 to 40,000 years. For age-dating waters, the best accuracy is obtained when the 14C data is used within the constraints of a geochemical reaction path model which accounts for the sources and sinks of carbon along the flowpath (Plummer et al., 1983; 1991).
The hydraulically inactive pore spaces and microfractures, respectively, are the main source for alpha-recoil, while recoil supply from large fractures may be negligible due to their relative low brine-rock interaction rates.
Abstract: To date the characteristics of abiogenic hydrocarbons have not been well defined. Studies of terrestrial abiogenic gases have shown that measuring the delta 13C value of methane alone is not always diagnostic. If the source of carbon is mantle-derived, as at the mid-ocean spreading centers, the delta 13C value of the methane would be expected to be relatively enriched in 13C. Away from mantle carbon input however, in crustal-dominated systems such as deep Precambrian Shield rocks, processes of water-rock interaction (including serpentinization) produce abiogenic hydrocarbons that may have much more isotopically light (12C-rich) signatures, reflecting local crustal carbon sources. Drawing on field data from terrestrial abiogenic gases and recent laboratory experiments, this paper will address key parameters that may be used as diagnostic tools for identifying biogenic hydrocarbons versus abiogenic geological sources of methane and other hydrocarbons, in particular the pattern of 13C and 2H variation between methane and higher hydrocarbon gases such as ethane. 2b1af7f3a8