@farmerman,
farmerman wrote:
I have no idea why Im even doing this but heres a place to start its a beginning U level petrology club at U of Washington.
Ok, I'm going to respond to this to show you how lay people read it:
Quote:" Methane and Hydrogen Formation From Rocks – Energy Sources for Life
Energy sources for what kind of life? Where do the methane and hydrogen come from? I.e. what energy source makes them to begin with?
Quote:One of the distinct geological characteristics of Lost City is that it lies upon basement rocks that originated in the Earth’s mantle and were brought to the surface through faulting.
What is 'Lost City?' What is 'faulting' and how does it bring 'basement rocks' to the surface? Does 'faulting' refer to earthquakes' 'fault lines?' I.e. are we talking about transform plate boundaries shifting? That is the term taught in K-12 regarding earthquakes and their fault lines.
Quote:These rocks are called peridotites and consist of minerals that are rich in magnesium and iron. The most common is the mineral olivine, which consists of magnesium, ferrous iron and silica. Below temperatures of about 425°C (about 800° F), olivine is unstable in the presence of seawater and reacts to form the hydrous Mg-rich silicate mineral serpentine and an iron-oxide called magnetite. We refer to this process of hydrating mantle rocks as “serpentinization”. Serpentinization causes important changes to the physical state of the rocks and the chemical composition of the system, and produces important nutrients for microbial activity.
I've read this. It doesn't explicate anything about the chemical pathways energy takes.
Quote:During the formation of magnetite, part of the ferrous (Fe2+) iron in olivine is oxidized to ferric iron (Fe3+) to form magnetite. This change in the valency of iron consumes oxygen from the fluid and leads to a state that chemists call reducing conditions. As a consequence of the formation of magnetite, hydrogen gas (H2) is produced from the reduction of seawater during serpentinization. Seawater also contains carbonate ions (HCO3- or CO22-) and sulfate ions (SO42-) which can become reduced to form methane (CH4) and hydrogen sulfide (H2S) during the serpentinization process. The presence of the reduced species H2, CH4 and H2S in the fluids that seep out of the rocks provide important energy sources for different microbial species that seem to thrive around the Lost City structures.
Here it sounds like the energy-containing H2 and methane break away from the cooling material, which is rich in energy because it was hot before it cooled, but I am assuming this is implied and I could be misinterpreting/analyzing.
If you apply this to explain Mars methane, you would have to assume that Mars had a hotter core/mantle that cooled and magma broke down into methane et al. and the methane is gradually venting out because of some seasonal cycle of freezing/thawing.
That's fine to hypothesize this kind of process, but why favor it over some other process that bears more resemblance to organic processes? Life is just a complex and extensive set of micro-chemical events that do what macro-geological mechanics do but on a nano-scale.
I have a hard time believing that life is either exceptional in the universe or that it doesn't exist on a continuum with abiotic processes, rather than as a radically different category, as is usually assumed.
Quote:In recent years, many scientists that have studied the mid-ocean ridge system have detected the presence of elevated concentrations of methane (and in some cases hydrogen) in the water column using a CTD package similar to the one that we will be using. These chemical anomalies have been found in a number of areas, particularly along the Mid-Atlantic Ridge. In many cases, the high methane concentrations can directly be linked to the presence of mantle rocks exposed on the seafloor that are undergoing serpentinization reactions. One of the goals of our expedition to Lost City will be to combine studies of the mineralogy and chemistry of the rocks with studies of the vent fluids, water column samples, and microbiology to better understand the links between the inorganic processes in the subsurface with biological activity around the vent structures. [/i]"
Ok, now I get you are talking about deep sea volcanic-vent based ecosystems. I often wonder if there's not a more continuous spectrum of energy-activities between what we consider life and what we consider abiotic magma. Life is thought to have begun with thermophiles as found in hot springs, etc. so there must be a spectrum of forms that leads back to abiotic magma processes. I.e. there shouldn't ultimately be any clear dividing line between magma and primordial life formation.
