I agree it does look like rhyolite but not necessarily from a Nuee Ardente, intrusive aphanitic, felsic rocks such as rhyolites whether in the form of a dyke or a sill can form banding. But without at least a hand specimen we will only ever be speculating;(
Really good call though for an amateur:-) I'm not sure if Mars is a silica rich planet like earth. Without silica it would be unlikely for quartz to form, and without quartz; no rhyolite...
Just because a rock has layers doesn't mean it's sedimentary.
I agree entirely the chances of what seems to be a cemented sedimentary rock forming on Mars would change my whole opinion of the planet. The cementation alone would require the introduction of fluid medium and the cement itself whether that is calcium based such as a lime, or siliceous such as you find in a chert. For the cracking to have formed through the release of overlaying pressure would require there to have been more layers above and then for it to have been either exposed through erosion of thrust up from some tectonic force. Both of which are more than possible on a harsh planet like mars but the fact that the layer would have needed to be buried so deep in the first place I find unlikely.
More likely the regular box shaped cracks are the product of contraction during cooling. These cracks are then exploited by chemical and or mechanical erosion, probably Aeolian in nature. The banding is likely caused by minor lithological separation during intrusion of the dyke. As the hot magma touches the cooler 'country' rock it starts to solidify on the outside at the contacts and preferentially drags some mineral crystals that are starting to form.
Really interesting stuff.
Interestingly there seems to be some sort of horizontal feature that in a terrestrial rock could very well be stratification, which would make it a sedimentary rock. I would guess that it's more likely some sort of weathering effect. Although you do quite often see this sort of effect in dykes.
Very interesting:)
I work and purchase computers for a large company that has a standing offer with Dell. Every couple of years Dell give us a presentation on how good they are and where their product line is going. I've asked about the inclusion of AMD based workstations in their product line and always been given the "Intel is technically superior", (which means 'we have a deal with them').
Mind you this is from a company that gave us a long winded presentation on the merits of RDRAM and why we must have it and why all other RAM types will die a quick death...
My ISP openly uses the MAC address of the cable modem to authenticate my account so even flushing the modems cache will normally give you the same IP as long as the lease hasn't expired AND the ISP is not pressed for IP's.
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Dude did you even read past the first paragraph of the parent post? You are agreeing with him without even realising it.
True but ESRI are actually including Python with the ArcGIS 9 installation :)
I agree it does look like rhyolite but not necessarily from a Nuee Ardente, intrusive aphanitic, felsic rocks such as rhyolites whether in the form of a dyke or a sill can form banding. But without at least a hand specimen we will only ever be speculating ;(
:-) I'm not sure if Mars is a silica rich planet like earth. Without silica it would be unlikely for quartz to form, and without quartz; no rhyolite...
Really good call though for an amateur
Just because a rock has layers doesn't mean it's sedimentary.
I agree entirely the chances of what seems to be a cemented sedimentary rock forming on Mars would change my whole opinion of the planet. The cementation alone would require the introduction of fluid medium and the cement itself whether that is calcium based such as a lime, or siliceous such as you find in a chert. For the cracking to have formed through the release of overlaying pressure would require there to have been more layers above and then for it to have been either exposed through erosion of thrust up from some tectonic force. Both of which are more than possible on a harsh planet like mars but the fact that the layer would have needed to be buried so deep in the first place I find unlikely.
More likely the regular box shaped cracks are the product of contraction during cooling. These cracks are then exploited by chemical and or mechanical erosion, probably Aeolian in nature. The banding is likely caused by minor lithological separation during intrusion of the dyke. As the hot magma touches the cooler 'country' rock it starts to solidify on the outside at the contacts and preferentially drags some mineral crystals that are starting to form. Really interesting stuff.
Interestingly there seems to be some sort of horizontal feature that in a terrestrial rock could very well be stratification, which would make it a sedimentary rock. I would guess that it's more likely some sort of weathering effect. Although you do quite often see this sort of effect in dykes. Very interesting :)
I work and purchase computers for a large company that has a standing offer with Dell. Every couple of years Dell give us a presentation on how good they are and where their product line is going. I've asked about the inclusion of AMD based workstations in their product line and always been given the "Intel is technically superior", (which means 'we have a deal with them'). Mind you this is from a company that gave us a long winded presentation on the merits of RDRAM and why we must have it and why all other RAM types will die a quick death...
Wow Dell trying to relax their ties with Microsoft, who knows we may see a Dell system with AMD hardware one day ;-)
My ISP openly uses the MAC address of the cable modem to authenticate my account so even flushing the modems cache will normally give you the same IP as long as the lease hasn't expired AND the ISP is not pressed for IP's.