Rovers on Mars

Hi, rosborne.
I have just found an article about concretion on the earth:

http://www.ugs.state.ut.us/online/pdf/pi-77.pdf

(I have not read it through yet.)

I would not have picked those thingys as concretions but, now knowing the chemistry, i guess the solubility of iron pyrite in a salt medium led to a type of sedimentary deposit called a reduzate, where a K brine develops and pyrite oxidizes and hydrolizes and forms the jarosite. The only jarosiste and argentojarosite Ive ever come across is in small hexagonal crystals in rock cracks and sedimentary surfaces. this "blueberry" depositing means that the blueberries came first and then were cemented into place, then some other rocks in a tab form were dissolved out to form the vugs. This is all new to me that Im like a schoolkid learning new tricks to look for. The chemical (redox) situation means that this was probably in a low pH environment that had just enough oxygen to cause Fe S to go to the Fe+++ SO4-- (OH-) and pick up a k from (probably) brine. That would provide a model that the water available was still plentiful cuz K salts precip at lower concentrations than do Na b rines. There is a place in Turkmenistan called the Gulf of Kara bogas wherein the various salts have separated and formed desert like deposits of brines of Na , K and metal chlorides and sulfates . the similarity is that the Gulf has actual discrete zones where these minerals precip .
I looked it up in my Dana and found similar "Mammilary" concretions in Chocoya Bolivia. Every where else its found as crystals (indicating a continuous wet solution of Fe SO4 and k2 SO4).

I thought those little blueberries were spherules from a volcanic source. I should have been more careful cause there were so many in unique layers. i thought they were periodic eruptions , when, more likely they were formed in zones that were more permeable to water and the water formed solutions and as it dried, they precipitated. Im still not convinced because the concretions in the Bolivian specimens, actually show more distinct layering and , according to my mineral properties handbooks, the hardness of jarosite is like 2.5 to 3.5. That drill should have torn the crap out of the little beads. instead they look like they really can take the grinding. I dont have any specs on the bit, maybe it was really high speed and soft metal, but you could see the salt dust all over the rock face .
Im gonna get a bowl of chips and keep watching as more stuff comes over the wire.

Hi Satt,

Page 12 of the document you linked shows Hematite concretions which are very spherical (just like the ones on Mars), however, when they are sliced open, they have very distinct internal structure, which is very unlike the ones on Mars.

Interesting though.

I'm sticking with some sort of molten liquid that solidified on hitting water, at least for some of those objects (spherules). Several of them have spurs, one had what looked to me like steam pitting and one had a belly button. Those are all the kinds of features you get when you drop molten lead, or glass into water. There are probably a number of different phonomania that are being classified under the category "blueberrys" and it wouldn't surprise me if we see a lot of "clarification".

Hi Farmerman,

Like you, I thought that the spherules were in different layers due to repeated events which produced them. But in my case, I thought that they came from impacts (instead of volcano's) as evidenced from the myriad of craters on the surface of Mars. The lower (than Earth) Martian gravity would allow larger tektite size to develop, as well as providing for a wider distribution of material after an impact.

The NASA guys argued that the fact that the spherules were distributed evenly in the rock layers that they could not have come from specific events (such as eruptions or impacts). But that argument seems a bit limited. For one thing, it ignores the fact that the spherules don't have an internal accretion structure, and they don't seem to be associated with any spaces in the rocks. Instead, they seem to be solidly embedded in dense material.

I was guessing that there might have been an almost constant rain of material (spherules as well as ash and rock debris) which was accumulating and solidifying over a long period of time. I figured it was all landing in water, and accumulating on the floor of a shallow sea or something.

I wish the NASA scientists would detail their argument for accretion a little bit better. Why doesn't even one of those blueberries have an internal structure?

I do not think we have seen the internal structure of "spherules" fully.

My impression is, "The Earth is a wonderful place!"

we owe satt a beverage of his choice as he picked up on thev sed nature of the rocks first. Whatll it be?

Water, of course.

Well, it's certainly *possible* that we haven't seen the internal structure we expect yet, and the NASA scientists would seem to agree with you, but with respect to the scientific method, shouldn't we try to form theory from the evidence we *do* see, rather than what we *expect* to see.

One of the scientists noted that one of the spherules seemed to have surface patterns which seemed to match the surrounding rock layering, but far more of the spherules I see don't seem to show any sign of external layering. And none of them show internal structure even though several have been sliced open pretty cleanly.

I'm sure the NASA guys are right, but I just don't understand all the details yet. I still wish they would produce a more comprehensive list of evidence to support their deduction.

This is the NASA press release for 3/3/04

Evidence of a Water-Soaked Past

This navigation camera image taken by the Mars Exploration Rover Opportunity on the 36th martian day, or sol, of its mission (March 1, 2004) shows the layered rocks of the "El Capitan" area near the rover's landing site at Meridani Planum, Mars. Visible on two of the rocks are the holes drilled by the rover, which provided scientists with a window to this part of the red planet's water-soaked past.
Scientists used the rover's microscopic imager and two spectrometers to look at the details of the freshly exposed, clean surfaces created by the rover's rock abrasion tool. Seeing beyond the veil of dust and coatings on the surface of the rock, scientists obtained the best views of the chemical composition of the areas. These data indicated that the rocks are made up of types of sulfate that could have only been created by interaction between water and martian rock.
The chemical make-up of the two holes is slightly different, giving scientists an inkling into the geologic history of this area. This history may help to explain the origin of the granular hematite found around the small crater cradling Opportunity and the "El Capitan" rock region.
The sulfates and the other chemicals found in the rocks at this location on Mars also occur on Earth, but only rarely. In places like Rio Tinto, Spain, similar minerals are forming today, and microorganisms live and thrive there.
Analyzing these two clean surfaces created by the rock abrasion tool proves that Mars had interactions between water and rock over extended amounts of time. Life on Earth is sustained by extended interaction between water and the environment. The fact that scientists have now found evidence of a similar relationship between water and rock on Mars does not necessarily mean that life did develop on Mars, but it does bring the possibility one step closer to reality.

These guys are inching ever so carefully towards a second big anouncement

Link to photo

Link to NASA press release

I hope it's more revealing that the last announcement. Don't get me wrong, it's nice to have confirmation that Mars has been soaked in water at some time in its past, but we pretty much already knew that. The flood indications on the surface convinced most scientists quite a while ago, this just corroborates it.

It would be a lot more exciting if they announced something we weren't pretty sure of already.

rosborne..
At least, as to gullies on Mars there has been a view that they might be formed through liquid CO2, not water.

http://unisci.com/stories/20012/0402013.htm
(April 2, 2001)

And hence the confirmation on the actual surface of the past flowing water is a very remarkable result.

Hi Satt,

Yeh, I remember reading those articles a while ago. I knew that there were some who speculated CO2, but most thought that was unlikely, and that regular old H2O was probably a more likely cause of the gullies.

Anyway, the confirmation from the rovers is nice.

Confirmation of water was crucial particularly the evidence of relatively still, mineral saturated water the rover seems to have found. There are many kinds of mineral deposits and many of them iron and sulfur based, that are created by the excretory processes of microbes. I would imagine that is what the earth based analysis, and possibly the rover is going to concentrate on now.

I hear that the rovers have no equipments for biological studies.

Certain mineral deposits are, or can be, bio-generated. That is what I suspect they will be looking for.

There was an eclipse on Mars by Deimos.

http://origin.mars5.jpl.nasa.gov/gallery/all/opportunity_p039.html

Anyone have any guesses as to the composition of those blueberries?

Could they be Hematite? Does Hematite form spherules like that?

Well, it looks like the spherules are mostly hematite: http://www.cnn.com/2004/TECH/space/03/18/mars.blueberries/index.html

According to the following, the making of the "blueberries" seems yet to be clear, though they are hematite-enriched.

http://www.csmonitor.com/2004/0319/p25s01-stss.html