Re: Extremophile Mars
From: george (george_at_wtfiswrongwithyou.com)
Date: 11/26/04
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Date: Fri, 26 Nov 2004 11:30:57 GMT
"jonathan" <Write@Instead.com> wrote in message news:41a6968e$1_1@127.0.0.1...
>
> "george" <george@wtfiswrongwithyou.com> wrote in message
> news:uj%od.664075$8_6.88469@attbi_s04...
>>
>> "John Thingstad" <john.thingstad@chello.no> wrote in message
>> news:opshyqfuiypqzri1@mjolner.upc.no...
>> > On Wed, 24 Nov 2004 05:38:30 GMT, george <george@wtfiswrongwithyou.com>
>> > wrote:
>> >
>> >>> This is just not true. Mars is now believed to experience
>> >>> ice-ages, and is thought to be exiting one right now.
>> >>> Also hydrothermal springs are obvious at Meridiani.
>> >>
>> >> You are insane. Go back to your square roots and leave the geology to us
>> >> geologists, Johnny boy. Any hydrothermal emissions that may have
>> >> occurred
>> >> there
>> >> were long ago (at least a billion or more years ago). Meridiani is as
>> >> dead
>> >> as a
>> >> door knob on the surface today, dork. AND THERE ARE NOT, NOR HAVE THERE
>> >> EVER
>> >> BEEN SPONGES ON MARS.
>> >>
>> >>
>> >
>> > I have heard the same.
>> > That is that Mars is in a ice age.
>> > Calling someone insane is futile.
>> > But if you are willing to pair data maybe somthing
>> > constructive could come from this.
>> > I have, by the way, also heard that Mars is volcanically inactive
>> > and that the core is thougt to be cold.
>> >
>>
>> I was referring to his lie that NASA has said that there are or were
>> hydrothermal emissions at the opportunity landing site. The data collected
>> so
>> far does not in any way support such a contention.
>
>
> Well, if Nasa says the hematite there typically forms in
> ....warm water.. what else is one to conclude? Any
> water flow on Mars must come from underground.
Warm water? Care to provide a link to MER data that clearly demonstrates the
hematite at Meridiani Planum was formed in warm water? Hematite, by the way,
doesn't have to have warm water in order to form. Hematite can and does form in
low water temperature lake/basin waters, and/or in association with evaporite
deposits. The hematite-bearing banded cherts of the Great lakes region (the
largest hematite deposits on earth) were formed in a low water temperature
environment. Guess what occurs at the Opportunity landing site? Evaporites.
And there is no evidence to suggest that all ancient water on Mars had to
originate from underground. It is abundantly clear that the Martian atmosphere
was more dense than it is today. In fact, there is evidence that is was dense
enough to have allowed the formation of lakes and streams, and possibily small
basins or seas. Considering the rate of Atmospheric loss at Mars today, and
extrapolating back in time, it is evident that the possibility exists that water
was relatively abundant billions of years ago, if for only a relatively short
time , geologically speaking. I know of no one who has worked out a possible
ratio of meteoric to primary water that once existed on Mars. There simply is
not enough data yet to make even a guess. That there once was, and possibly
still are springs on Mars is intriguing. That there presently is any primary
water emanating from Mars is highly doubtful. Given the evaporitic nature of
the surface exposed rock layers seen at Opportunity, and the mineral assemblage
that has been determined to occur there, there is no reason to suspect the
hematite to have formed in warm water. In fact, the presence of evaporites at
Meridiani planum argues against a warm water origin.
>
> And in case you think the following quote is from some
> crackpot, I'll post the authors biography below, this is
> the fella I read to find out what's-what on Mars. And guess
> what his specialty is...hydrothermal systems? And it
> is Dr Farmer that Nasa has been quoting in the
> Rover updates. Given his specialty, that is a
> Huge Clue guys.
I'm happy for him. Guess what my specialty is? Hydrogeology.
>
> Morphological Biosignatures and the Search for Life on Mars
>
> "Determining the location of potential paleobiological repositories
> on Mars requires an understanding of the martian surface in
> terms of elemental abundances and mineralogy. This variety
> of hematite on Earth forms only in the presence of large amounts of
> water, and typically at elevated (hydrothermal) temperatures
> (Christensen et al., 2000)."
> http://geology.asu.edu/jfarmer/pubs/pdfs/morpho.pdf
>
"Typically" but not exclusively at elevated temperatures. Note that Glotch,
Morris, Sharp, and Christenson (2003) indicated that:
http://www.lpi.usra.edu/meetings/lpsc2003/pdf/2008.pdf
"A variety of formation mechanisms has been proposed for the martian hematite
deposits [1-5], including aqueous and non-aqueous processes. Comparison of the
average Sinus Meridiani hematite spectrum measured by TES to laboratory
emissivity spectra for a variety of naturallyoccurring hematites shows small but
potentially important differences. In particular, the emissivity minimum at 300
and 445 cm-1in the Sinus Meridiani (SM) spectrum is displaced 10-25 cm-1 to
lower frequencies compared to some natural hematite samples [6]. In addition,
these bands in the TES data are narrower than the broad bands seen in many
natural hematite spectra. These differences may imply that the natural
variability of hematite spectra has not been fully characterized, especially
with respect to the reaction pathway (precursor mineralogy and temperature of
hematite formation)and crystal morphology."
They went on to discuss laboratory experiments that were conducted with goethite
(the primary source of the hematite at Meridiani) alteration to hematite under
various parameters of formation. Their conclusions was:
"Based solely on the laboratory spectra, the closest match to the SM hematite
spectrum is a goethite-derived sample heated at 300°C. Review of the literature,
however, points out that on Mars, goethite would be unstable relative to
hematite under all geologic conditions [9-12]. Given appropriate time and
pressure, the martian crystalline hematite deposits could have formed at
temperatures as low as40°C".
Do note that since both of these papers were written, things have changed,
because the data that has been received to date indicates that although the
hematite is likely secondary after goethite, the presence of the evaporite
deposits places strict limits the temperature of formation. In addition, the
fact that these deposits reveal primary sedimentary structures, such as
cross-bedding, indicate that they were formed at ambient temperatures (i.e.,
typically lake or basin water temperatures). Hence it is highly likely that the
hematite at the Opportunity landing site was formed in a low-temperature
environment.
> Besides look at this picture, clearly outcrop water flow.
> http://mars.gh.wh.uni-dortmund.de/mer/opportunity/269/tn/1P152067393EFF37B5P2438L5M1_L2L5L5L7L7.jpg.html
Johnathon. You really should take some geology classes before you post to the
geology newsgroup. You are seeing wind-blown and eroded grains which have been
"wind-deposited" into fractures exposed at the surface in bedrock at endurance
crater (a which is an impact crater with all the characteristics of impact
craters, including an ejecta blanket, highly fractured bedrock, tilted bedding,
etc).
> And look at the fans, only water could undercut the rocks. Does
> anyone think this pic shows a million year old scene???.
> More like millennia old at best, or before the current ice age.
> http://marsrovers.jpl.nasa.gov/gallery/all/1/n/297/1N154552477EFF3897P1992L0M1.JPG
> http://marsrovers.jpl.nasa.gov/gallery/all/1/n/297/1N154552440EFF3897P1992L0M1.JPG
This is why little weazels like you should stick to you chosen profession
instead of trying to interprete things for which you have no experience or
training. There is nothing extraordinary in the images with regard to the
deposition of the talus and detritus along the base of the outcrop. Those fans
are very easily explained by the simple fact that they point straight towards
eroded fractures that occur vertically (or nearly so) along the face of the
outcrop, and lead all the way to the surface above the crater. As the wind blows
over the crater rim it experiences a velocity change, a reduction in windspeed
that allows windblown particles to drop out. Particles will then collect in the
fractures, but because the fractures are exposed along the cliff face, the
deposit will eventually slump and slide out into the crater in the form of a fan
over top of the talus slope. It looks like a million other outcrops exposed on
earth. A million years old? Considering the rate of wind-blown deposition of
particles onto the surface of the rover itself, try hundreds of millions of
years, at a minimum.
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