thaumaturgy
Well-Known Member
Gosh all, I'm sad we didn't stay on the geology of the Grand Canyon. I'm no expert on it but it sure is fun to learn more about it.
Take for instance the Muave Limestone
It's down near the bottom. Now what's apparently really cool about the Muav Ls is that it has deep channels that were carved in the TOP OF IT! Little minicanyons if you will! Interesting. Because that means it was at least consolidated enough to be erodable. But then these were filled in with freshwater limestone!
History within history.
Also note that no rocks that can reasonably be interpretted to have been from the Ordovician or Silurian are seen in the geologic column. Hmmm, either they weren't deposited or they were eroded away.
Either way, no matter what you think about how the layers of the canyon formed, you have to wonder why rocks that would be present elsewhere in the world indicating either a type of animal population or another identifiable marker, simply didn't get deposited here.
Further up the column they find stuff in the Supai Group that can be traced back to the Ancestral Rocky Mountains! So these mountains (which existed before the current Rocky Mountains) formed, eroded and their detritus was accumulated in a shallow sea to the west, all before any Canyon building stuff happened. And the Ancestral Rockies were probably Precambrian metamorphic rockswhich means eroding them may not have been a "fast job". But I don't know for sure what their mineralogy was.
Remember Steno's Law of "Cross Cutting Relationships" which essentially tells you if you have a feature and some other feature (like a giant canyon or gash) cuts across that feature the feature being cut was there FIRST!
Wow, the levels of history are stunning.
Keep going up and you see the HERMIT SHALE. This was laid down by freshwater streams and has fossils of winged insects and ferns in it! On top of that we have a full-on dune deposit as discussed earlier.
The formation above that, the Toroweap Fm has interbeds of gypsum. Gypsum forms when water that is very saline is allowed to stand and evaporate to the point where there is so much Ca and sulfate in the water that it dumps out gypsum.
So you go from a freshwater stream type environment to a desert to a shallow sea, then another formation, the Kaibab, that marks more sea deposition,
But what I DON'T see is the evidence of a world-altering high energy super massive flood or evidence of the fountains of the deep erupting or a giant flux of water that suddenly swept in to deposit all this. What we do see are numerous instances of ocean and land and shallow calm seas and fresh water cutting down through the ground, and more seas and more land.
Just like we see happening today all over the planet.
Can someone please point out where the Flood happened in the stratigraphy?
It's pretty simply laid out there, let's find the Flood layer, shall we?
To the Original Poster: Please point out where the flood happened or explain how a single flood lasting a year deposited, lithified and then cut through so many differing deposits all in a nice package.
Take for instance the Muave Limestone
It's down near the bottom. Now what's apparently really cool about the Muav Ls is that it has deep channels that were carved in the TOP OF IT! Little minicanyons if you will! Interesting. Because that means it was at least consolidated enough to be erodable. But then these were filled in with freshwater limestone!
History within history.
Also note that no rocks that can reasonably be interpretted to have been from the Ordovician or Silurian are seen in the geologic column. Hmmm, either they weren't deposited or they were eroded away.
Either way, no matter what you think about how the layers of the canyon formed, you have to wonder why rocks that would be present elsewhere in the world indicating either a type of animal population or another identifiable marker, simply didn't get deposited here.
Further up the column they find stuff in the Supai Group that can be traced back to the Ancestral Rocky Mountains! So these mountains (which existed before the current Rocky Mountains) formed, eroded and their detritus was accumulated in a shallow sea to the west, all before any Canyon building stuff happened. And the Ancestral Rockies were probably Precambrian metamorphic rockswhich means eroding them may not have been a "fast job". But I don't know for sure what their mineralogy was.
Remember Steno's Law of "Cross Cutting Relationships" which essentially tells you if you have a feature and some other feature (like a giant canyon or gash) cuts across that feature the feature being cut was there FIRST!
Wow, the levels of history are stunning.
Keep going up and you see the HERMIT SHALE. This was laid down by freshwater streams and has fossils of winged insects and ferns in it! On top of that we have a full-on dune deposit as discussed earlier.
The formation above that, the Toroweap Fm has interbeds of gypsum. Gypsum forms when water that is very saline is allowed to stand and evaporate to the point where there is so much Ca and sulfate in the water that it dumps out gypsum.
So you go from a freshwater stream type environment to a desert to a shallow sea, then another formation, the Kaibab, that marks more sea deposition,
But what I DON'T see is the evidence of a world-altering high energy super massive flood or evidence of the fountains of the deep erupting or a giant flux of water that suddenly swept in to deposit all this. What we do see are numerous instances of ocean and land and shallow calm seas and fresh water cutting down through the ground, and more seas and more land.
Just like we see happening today all over the planet.
Can someone please point out where the Flood happened in the stratigraphy?
It's pretty simply laid out there, let's find the Flood layer, shall we?
To the Original Poster: Please point out where the flood happened or explain how a single flood lasting a year deposited, lithified and then cut through so many differing deposits all in a nice package.
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