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Is there a Geologist in the house?
- Thread starter Mack
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Thanks!!!:thumbup:
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The rock looks like petrified wood. The black gooey stuff I have never seen before, I am sure it is not basalt. It looks like asphalt. But doing any analysis by picture is difficult. Anyway I think it is secondary and not originally related to the petrified wood.
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In the western deserts I've seen it often. Generally near lava flows. I'm just not certain as to what it is.
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Not sure, I will find out though. It is hard as rock even though it looks soft.
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it's probably some form of volcanic rock. there are multiple types.
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I have a pic taken near Bailey CO. I've seen this black gooey looking but hard rock before and assumed it was Basalt but as we know I'm not very bright.
What is it?
Isn't this the same stuff that changed Jed Clampett's life.
You always wanted a Cement Pond.
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It's hard to tell from the quality of the picture and without being able to handle it, but my guess would be volcanic glass. Obsidian is what we commonly think of, but what you found may be of "lower quality". Volcanic glass forms as liquid lava cools rapidly (not allowing for crystal growth) as it flows across the ground or fly's through the air. The bubbly look is formed as gas escapes from the lava.
Obsidian is classified as an extrusive igneous rock with a high silica content. This high silica content shows that it originated form a rhyolitic lava. Basalt, on the other hand, has a lower silica content. Your guess was pretty good though, because basalt typically has a dark color, whereas rhyolite is light in color (obsidian being the exception due to its formation).
Obsidian is classified as an extrusive igneous rock with a high silica content. This high silica content shows that it originated form a rhyolitic lava. Basalt, on the other hand, has a lower silica content. Your guess was pretty good though, because basalt typically has a dark color, whereas rhyolite is light in color (obsidian being the exception due to its formation).
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Looks like a coal seam to me. I'm not a gynocologist though
lambertiana
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It appears to be in sedimentary rock, so the setting is not correct for obsidian or basalt to show up in one spot like that. I have seen similar things, and I think it is caused by a seep. Mineralized water can carry things through seams in the rock.
I have a pic taken near Bailey CO. I've seen this black gooey looking but hard rock before and assumed it was Basalt but as we know I'm not very bright.
What is it?
When hit with a rock pick or hammer, does it give a dull thud or a sharp ring? Does it fracture with conchoidal fracture (like the inside of a shell), or like broken glass? If so the volcanic glass/obsidian theory is prob. correct, or an dense aphanitic volcanic rock.
Does it flow? It kinda looks like tar to me
Try to scratch it with a knife to see if it has a hardness >7, it would indicate siliceous rock at least.
The other rock looks like jointed basalt, if the black stuff is crystalline or glassy it might be a chilled surface.