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Author Topic:   Exploring the Grand Canyon, from the bottom up.
Jazzns
Member (Idle past 1988 days)
Posts: 2657
From: A Better America
Joined: 07-23-2004


Message 76 of 282 (295954)
03-16-2006 12:47 PM
Reply to: Message 75 by jar
03-16-2006 12:30 PM


Re: A few more questions before moving on to the Bass Limestone.
Q1. Rox or someone will have to answer that for certain.
Q2. I suppose the answer to that question would be that we can never know because erosion has destroyed that evidence. All we can say is that the sandstone came first and the instrusion after. How far they extened is unanswerable. For all we know there were a dozen other layers above the sandstone that the magma also intruded into that are now lost to erosion. (Acutually this might not be totally unknowable depending on the position of the schist and other layers that might not have been eroded somewhere else other than the GC. Just given this information alone it is unknowable.)
Q3. According to Rox's last post it sounds like the metamorphism and the melting of the granite happened sort of at the same time which sort of makes sense if some of the metamorphism is due to the magma. Rox had a good description of how some of the intrusions spread along the lines of deformation suggesting that they were all contemporaneous. The granite though may not have fully solidified until later. Granite in particular is a result of slow cooling.


Of course, biblical creationists are committed to belief in God's written Word, the Bible, which forbids bearing false witness; --AIG (lest they forget)
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jar
Member
Posts: 30934
From: Texas!!
Joined: 04-20-2004


Message 77 of 282 (296064)
03-16-2006 6:37 PM
Reply to: Message 76 by Jazzns
03-16-2006 12:47 PM


Calling a Geologist to aisle 14 !!!!
No problem. That'spretty close to what I thought. We'll need to get Roxrkool or one of the other geolgists to help firm things up.

But I would like to get this cleared up before we move on.

see Message 75


Aslan is not a Tame Lion
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roxrkool
Member (Idle past 973 days)
Posts: 1493
From: Nevada
Joined: 03-23-2003


Message 78 of 282 (296109)
03-16-2006 10:22 PM
Reply to: Message 75 by jar
03-16-2006 12:30 PM


Re: A few more questions before moving on to the Bass Limestone.
Now Question 1.

Does the accumulated sand need to be under pressure of an overlying layer to change from sand to sandstone, or is it simply that the lowest layers of sand are compressed by the weight of overlying sand?

Would it simply be a layer that is sand at the top gradually turning to sandstone as the weight and pressure increase with depth.

1. Generally, all you really need for lithification and/or induration of marine rocks is compression (gets all the water out) and it helps to have some sort of cement or maybe even a fine-grained component such as clay. So more deeply buried sediments are more likely to harden than shallow sediments. Diagenesis, which is basically very mild form of metamorphism, happens soon after deposition sometimes and this too will help 'set' the sediments. Your last sentence is possible.

Question 2.

Is it likely that the magma intrusion extended through the layer of sand--->sandstone and that what happened is the the softer protosandstone layers that also contained magma were what was eroded away before the Bass Limestone and other layers were laid down?


Jazz answered this question well, but yes, what you stated is possible as far as I know.

I haven't read many papers about the Precambrian strata in the area, so I don't know if a 'complete' section exists (between the Vishnu and the Supergroup) elsewhere in the area.

Question 3.

When did the sandstone become schist and the magma become granite? Wouldn't both have to be buried under lots of material to create the temperatures and pressures need for sandstone ---> schist and magma ---> granite?


Jazz also answered this one well. Based on other papers, it seems that most workers agree the schist and the granite formed at about the same time, especially at depth. There is some question whether the granite formed from the schist or whether the granite is a completely separate body of magma. The paper I linked to earlier (Ilg et al., 1996) state that, based on metamorphic mineralogy, peak temps in the study area reached as high as about 725 degrees Celsius and depths of about 22 km.
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jar
Member
Posts: 30934
From: Texas!!
Joined: 04-20-2004


Message 79 of 282 (296111)
03-16-2006 10:31 PM
Reply to: Message 78 by roxrkool
03-16-2006 10:22 PM


Moving on to the Bass Limestone layer.
The next layer to discuss is the Bass Limestone layer of the Grand Canyon Supergroup.

Please.

When talking about the Grand Canyon Supergroup I don't want to get into anything that happened to it yet. I just want to try to stick to a layer by layer exploration of what it is composed of and what that tells us.

So...

Limestone is something we haven't mentioned yet.

Question 1
What is Limestone?

Question 2
What does the change from sandstone to limestone tell us?


Aslan is not a Tame Lion
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Minnemooseus
Member
Posts: 3708
From: Duluth, Minnesota, U.S. (West end of Lake Superior)
Joined: 11-11-2001
Member Rating: 3.9


Message 80 of 282 (296136)
03-17-2006 5:27 AM
Reply to: Message 79 by jar
03-16-2006 10:31 PM


Re: Moving on to the Bass Limestone layer.
First of all, I'm going to repost the strat column originally posted in message 8.


Click to enlarge

SOURCE of the section.

The first question, "What is limestone?", has and is being discussed in the currently active Limestone Layers and the Flood. I don't see any point in rehashing that material here. The esential point there, is that limestone is mostly a direct or indirect product of biological activity.

The interesting point is that the Bass Limestone is a preCambrian limestone; Per the diagram, it has an age of 1250 million years. preCambrian limestones are relatively uncommon.

Per the second question, the sandstone/limestone transition - The Bass Limestone unconformibly overlies the Vishnu Schist, dated at 1700 million years. As such, there was no real transition from sandstone to limestone. The Bass was some sort of (marine?) deposit upon a schist/granite surface.

The interesting point, as I see it, is how did the Bass Limestone form, being that it is seemingly of an age before much any biologically produced calcium carbonate. In other words, the research topic is preCambrian limestones, or more specificly, Proterozoic limestones.

By the way, I have just noticed that the "preCambrian" in the diagram is designated as being a geologic period. That is wrong.

The geologic time scale is divided into the preCambrian and Phanerozoic. The preCambrian is in turn divided into the older Archean era (aka Early preCambrian) and the younger Proterozoic era (Proterozoic = proto life) (aka Late preCambrian). The Phanerozoic consists of the Paleozoic era (Paleozoic = early life), the Mesozoic era (Mesozoic = middle life), and the Cenozoic era (Cenozoic = recent life).

Moose

Added by edit: Possibly relevant article (abstract only, full paper access requires membership)

Temperature and salinity history of the Precambrian ocean: implications for the course of microbial evolution

Abstract

The temperature and salinity histories of the oceans are major environmental variables relevant to the course of microbial evolution in the Precambrian, the “age of microbes”. Oxygen isotope data for early diagenetic cherts indicate surface temperatures on the order of 55–85 °C throughout the Archean, so early thermophilic microbes (as deduced from the rRNA tree) could have been global and not just huddled around hydrothermal vents as often assumed. Initial salinity of the oceans was 1.5–2× the modern value and remained high throughout the Archean in the absence of long-lived continental cratons required to sequester giant halite beds and brine derived from evaporating seawater. Marine life was limited to microbes (including cyanobacteria) that could tolerate the hot, saline early ocean. Because O2 solubility decreases strongly with increasing temperature and salinity, the Archean ocean was anoxic and dominated by anaerobic microbes even if atmospheric O2 were somehow as high as 70% of the modern level.

Temperatures declined dramatically in the Paleoproterozoic as long-lived continental cratons developed. Values similar to those of the Phanerozoic were reached by 1.2 Ga. The first great lowering of oceanic salinity probably occurred in latest Precambrian when enormous amounts of salt and brine were sequestered in giant Neoproterozoic evaporite basins. The lowering of salinity at this time, together with major cooling associated with the Neoproterozoic glaciations, allowed dissolved O2 in the ocean for the first time. This terminated a vast habitat for anaerobes and produced threshold levels of O2 required for metazoan respiration. Non-marine environments could have been oxygenated earlier, so the possibility arises that metazoans developed in such environments and moved into a calcite and silica saturated sea to produce the Cambrian explosion of shelled organisms that ended exclusive microbial occupation of the ocean.

Inasmuch as chlorine is a common element throughout the galaxy and follows the water during atmospheric outgassing, it is likely that early oceans on other worlds are also probably so saline that evolution beyond the microbial stage is inhibited unless long-lived continental cratons develop.

The above was found via a scirus.com seach for "Bass Limestone". Apparently it is relevant to the Bass Limestone, even though such is not mentioned in the abstract. Seemingly, the Bass Limestone is a result of microbial processes. Note also the "Cambrian explosion" mention.

This message has been edited by minnemooseus, 03-17-2006 05:59 AM


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roxrkool
Member (Idle past 973 days)
Posts: 1493
From: Nevada
Joined: 03-23-2003


Message 81 of 282 (296235)
03-17-2006 12:04 PM
Reply to: Message 80 by Minnemooseus
03-17-2006 5:27 AM


Re: Moving on to the Bass Limestone layer.
moose writes:

By the way, I have just noticed that the "preCambrian" in the diagram is designated as being a geologic period. That is wrong.


They also spelled "Vishnu" wrong. heh

Abe: Good post, by the way. I'll see if I can find some more on the Bass Limestone. I'm really interested in this portion of the thread. I don't remember ever reading any literature about the Supergroup, much less individual formations.

This message has been edited by roxrkool, 03-17-2006 12:16 PM


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roxrkool
Member (Idle past 973 days)
Posts: 1493
From: Nevada
Joined: 03-23-2003


Message 82 of 282 (296243)
03-17-2006 12:37 PM


Unkar Group
Here is an interesting figure that shows another package of rocks below the Bass Limestone and included in the Unkar Group - the Houtata Conglomerate. It does not appear to be a widespread formation and may pinch out against paleo topographic highs. Red lines are unconformities.


Click to enlarge

SOURCE of figure. The link also has the following:

Abstract

Unkar Group (1.25-1.10 Ga) shale geochemistry and petrography coupled with detrital zircon geochronology of interbedded sandstones, identify specific source terranes for Unkar Group sediments. The dominant sediment source for most of the Unkar group is the southern Grenville Orogenic Front (GOF). The Hakatai Formation is composed dominantly of GOF volcanic detritus with some material derived from the Southern Granite Rhyolite Terrane (SGRT) and the Yavapai - Mazatzal crustal provinces (YMP). Unconformably overlying the Hakatai is the Shinumo Sandstone, which is composed primarily of locally-derived YMP and SGRT detritus with a minor GOF component. The uppermost Dox Formation, which conformably overlies the Shinumo, is largely derived from the GOF. These data indicate that a protracted period of orogenesis along the southern GOF resulted in uplift of the interior Rodinian platform which evolved from an epicontinental sea or marine embayment to a foreland with well-developed fluvial drainage.

Variable provenance of the Unkar Group, as revealed by detrital zircon data and mineralogy, occurs despite relatively homogeneous bulk chemical trends. It is concluded that Unkar Group shales are a well-mixed recipe of variable ingredients that subtley reveal the distinct nature of the components. This is attributed to a number of factors that include; rapid rates of uplift and erosion along the GOF, the similarity in composition of a large number and volume of crustal domains (YMP and SGRT), a significant component of intraformational recycling, and the distal location of the Unkar Basin, ~800 km, from the dominant sediment source.

If you open up the PDF presentation in the above link, you can find the same figure on page 7 with interpreted depositional settings. The PDF document has some good pictures of shallow water sedimentary structures (ripples, dessication cracks, trace fossils, etc.). However, no text is available so it's impossible to know which formation we're looking at in each image. My guess is the images span the Unkar Group from the Bass Limeston to the Dox Sandstone.

OOPS!! It just occurred to me, Jar, this is generally discussing the setting for the lower portion of the Supergroup and ignores the Bass Limestone. Is this too much info? Should I perhaps remove the info until we get past the Bass Limestone?

I personally find it easier to understand the big picture first before diving into the details, but that may not work best for non-geos. Let me know what you think.

Changed img to thumbnail version to fix page width - The Queen

This message has been edited by roxrkool, 03-17-2006 12:49 PM

This message has been edited by AdminAsgara, 03-17-2006 12:32 PM


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roxrkool
Member (Idle past 973 days)
Posts: 1493
From: Nevada
Joined: 03-23-2003


Message 83 of 282 (296255)
03-17-2006 1:29 PM
Reply to: Message 79 by jar
03-16-2006 10:31 PM


Re: Moving on to the Bass Limestone layer.
Jar writes:

Question 2
What does the change from sandstone to limestone tell us?


First, what sandstone are you referring to, jar?

Second, THIS SITE appears to be pretty well researched and written. There really isn't a whole lot on the Bass Limestone, especially online, but I thought the following was an important observation (I noted the same thing in another thread about the term 'shale' being a misnomer):

"Bass Formation" has been proposed by some technical workers as a more accurate description who contend "Bass Limestone" is really somewhat of a misnomer due to the variety of rock types within this formation. The diversity of rock types composing the Bass is not atypical as virtually all of the strata in Grand Canyon popularly designated and labeled as "Sandstones", "Limestones" and "Shales" exhibit complex structures and members composed of differing lithologic types.

The Hotauta Conglomerate (apparently mispelled in the other figure) occurs in the basal portion of the Bass Limestone and this suggests the possibility of a more gradational transition into limestone/dolomite than previously thought.

It would be nice to see a strat column of the Bass Limestone and a picture or two of the stromatolites (algae) found in the Bass, but without digging through all the literature, that may not be possible.

More on the Bass:

Layer II – Algonkian Grand Canyon Supergroup (1.6 Ga – 850 Ma)

Post Mazatzal uplift and erosion set the stage for the deposition of Layer II (the Grand Canyon Supergroup which consists of the Unkar and Chuar Groups in Figure 24). Layer II consists of a vast sequence of intercalated sedimentary and volcanic rocks of predominately marine origin. The sequence starts with deposition of the Hotauta Conglomerate which grades upward into the Bass Limestone. The Hotauta contains fragments of igneous and metamorphic rocks of Layer I, preserved remnants of the older “Archean” sequence. The Bass Limestone (and dolostone) varies in thickness from 120’ to 340’ and forms the basal unit of the 3,000’ thick Proterozoic Unkar Group.

[SOURCE]


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Minnemooseus
Member
Posts: 3708
From: Duluth, Minnesota, U.S. (West end of Lake Superior)
Joined: 11-11-2001
Member Rating: 3.9


Message 84 of 282 (296347)
03-17-2006 5:29 PM
Reply to: Message 83 by roxrkool
03-17-2006 1:29 PM


Re: Moving on to the Bass Limestone layer.
The Hotauta Conglomerate (apparently mispelled in the other figure) occurs in the basal portion of the Bass Limestone and this suggests the possibility of a more gradational transition into limestone/dolomite than previously thought.

I would think that some sort of residual conglomerate would be expected at the unconfomity (nonconformity in this case). Such is said in the following quote box.

The sequence starts with deposition of the Hotauta Conglomerate which grades upward into the Bass Limestone. The Hotauta contains fragments of igneous and metamorphic rocks of Layer I, preserved remnants of the older “Archean” sequence.

I didn't look at the source article, as it takes a long time to download on my slow dial-up connection (the earlier mentioned PDF was even worse). I wonder how thick this gradation is? Are we talking along the lines of at most just a few feet? My image is that the gradation is limestone infilling of the conglomerates voids. In all, I suspect the conglomerate is a pretty insignificant feature.

Side note: The Vishnu is dated at 1700 million years. I presume this is the age of the intruding granites and of the metamorphic event. By saying "Archean" above, I presume they are talking about the age of the Vishnu protolith.

Side note 2: I note that in the diagram of message 8 (repeated in 80), the total thickness of the Grand Canyon Supergroup is along the lines of 12,000 feet. In the geological section of message 82, that thickness is 4000 feet. My guess is that the message 8 "thickness" is not a true stratigraphic thickness. Maybe it's exposure distance along the river?

Mucho kudos to roxrkool, for doing all the work to dig up the information, diagrams, and references. Many more POTM's should be coming your way, but that would mean we're again getting into the "roxrkool posts again, gets POTMed again" situation. Maybe you should get a GMOAPOTM (grand mother of all POTM) when this topic is concluded.

Moose


Professor, geology, Whatsamatta U
Evolution - Changes in the environment, caused by the interactions of the components of the environment.

"Do not meddle in the affairs of cats, for they are subtle and will piss on your computer." - Bruce Graham

"The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness." - John Kenneth Galbraith

"I know a little about a lot of things, and a lot about a few things, but I'm highly ignorant about everything." - Moose


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jar
Member
Posts: 30934
From: Texas!!
Joined: 04-20-2004


Message 85 of 282 (296382)
03-17-2006 8:31 PM
Reply to: Message 82 by roxrkool
03-17-2006 12:37 PM


Re: Unkar Group
I personally find it easier to understand the big picture first before diving into the details, but that may not work best for non-geos. Let me know what you think.

I'd like to hold off and move layer by layer. Here is the reasoning.

I too find that the big picture is more than enough to be convincing, BUT...

there are folk like Steve Austin and the others at ICR and AIG and the like that use the big picture to hoodwink and con the gullible into believing that the Grand Canyon could be the result of THE Flood. These folk claim to be scientists and as such should know better, yet they persist in trying their slight of hand to sell their books and videos. They are very good at it too; here is an example of the type of claim that Conmen such as Steve Austin use:

'The crystalline-basement rocks exposed deep within the Canyon (schist, granite, and gneiss) represent some of earth's oldest rocks, probably from early in Creation Week. Tilted, deeply buried strata (the "Grand Canyon Supergroup") show evidence of catastrophic-marine sedimentation and tectonics associated with the formation of an ocean basin midway through Creation Week, and may include ocean deposits from the post-Creation, but pre-Flood world.

from Answers in Genesis which is one of the most active Creationist sites.

Well, we have not yet even gotten beyond the very beginnings of the bottom layers of the Grand Canyon. We still have literally miles of rock layers to discuss, and we already have a scenario that simply can't be explained by the simplistic mutterings of the folk at AIG or ICR.

What I hope to do here is to build a step by step history of what can be known about the Grand Canyon. Then anyone who thinks they can explain what is seen can step up to the plate and try to come up with their best argument.

I would like to discuss though the Houta Conglomerate because it is essential for disproving the other major tool that folk like Walt Brown and Steve Austen drag out, hydrolic sorting.

Can you speak a little bit about both the layer, and what a comnglomerate is as opposed to another rock formation we will likely come across, a breccia.


Aslan is not a Tame Lion
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jar
Member
Posts: 30934
From: Texas!!
Joined: 04-20-2004


Message 86 of 282 (296383)
03-17-2006 8:35 PM
Reply to: Message 84 by Minnemooseus
03-17-2006 5:29 PM


Re: Moving on to the Bass Limestone layer.
Moose, I want to hold off on assigning dates to anything yet. I hope that the creationists can see this like those who first that we must abandon the idea of a Young Earth if we want to maintain and honesty. Let's not worry yet about how old something is and just stick to the things we can establish, like location, composition and ordering.


Aslan is not a Tame Lion
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jar
Member
Posts: 30934
From: Texas!!
Joined: 04-20-2004


Message 87 of 282 (296385)
03-17-2006 8:42 PM
Reply to: Message 83 by roxrkool
03-17-2006 1:29 PM


What sandstone???????
jar asked:

quote:
Question 2
What does the change from sandstone to limestone tell us?

to which Roxrkool replied

First, what sandstone are you referring to, jar?

Remember, at this moment what is today the Vishnu Schist was still but sand and sandstone and the intrusions were still just magma.

Please correct me if I'm wrong but I understood that there were several things needed to change rocks.

To change sandstone into schist I understood that it took time, higher temperatures and pressure.

To change the magma into granite I understood that it took time, long slow cooling and pressure.

Since we are still at that point in time were the Vishnu layer has been laid down and the magma intruding into it, there has not been any time for the transformation. In addition, so far there are no layers on top of the Vishnu layer so no pressure to cause the metamorphose.

Is that correct?


Aslan is not a Tame Lion
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roxrkool
Member (Idle past 973 days)
Posts: 1493
From: Nevada
Joined: 03-23-2003


Message 88 of 282 (296392)
03-17-2006 9:33 PM
Reply to: Message 84 by Minnemooseus
03-17-2006 5:29 PM


Re: Moving on to the Bass Limestone layer.
I would think that some sort of residual conglomerate would be expected at the unconfomity (nonconformity in this case). Such is said in the following quote box.

I agree. That's why it was interesting to see that the Bass Limestone is not purely a limestone-bearing unit. It's a bit hard to imagine how limestone would directly overlie metamorphic/igneous rocks. However, if the diagram is drawn accurately, it appears the conglomerate may pinch out in places so it's still possible we can find limestone directly on top of Vishnu.

I wonder how thick this gradation is? Are we talking along the lines of at most just a few feet? My image is that the gradation is limestone infilling of the conglomerates voids. In all, I suspect the conglomerate is a pretty insignificant feature.

I wish we had a detailed strat section, but what I'm thinking is coarse material at the bottom, sand above that, maybe a calcareous sandstone, and then limestone. Marine carbonate generally does not form in the presence of too much clastic material. Based on the following and what was stated in the Grand Hikes link, it appears conglomerates are present throughout the entire Bass Limestone and they are at least 4 or 5 feet thick.

THIS SITE states the following about the conglomeratic unit:

quote:
The Hotauta Conglomerate member, which is the lowermost unit of the Bass Limestone, was deposited in low areas of the Vishnu terrane. The Hotauta conglomerate is composed of rounded gravel-sized clasts of chert, granite, quartz, plagioclase crystals and micropegmatites in a quartz sand matrix. This conglomerate is found in the eastern Grand Canyon. In the western Grand Canyon, intraformational breccias and small pebble conglomerate make up the base of the Bass Limestone, suggesting the source of these clasts was to the east. It is also important to note that the clasts found in the conglomerate come from the Vishnu Complex, suggesting an extended period of erosion of the Vishnu terrane.

The last bolded portion is particularly interesting. We have Vishnu-derived rounded material at the base of the Bass Limestone.

Side note: The Vishnu is dated at 1700 million years. I presume this is the age of the intruding granites and of the metamorphic event. By saying "Archean" above, I presume they are talking about the age of the Vishnu protolith.

They are referring to the depositional age of the proto-sediments, but because they don't have any hard evidence, such as an absolute date, they are speculating, hence the quotation marks.

Side note 2: I note that in the diagram of message 8 (repeated in 80), the total thickness of the Grand Canyon Supergroup is along the lines of 12,000 feet. In the geological section of message 82, that thickness is 4000 feet. My guess is that the message 8 "thickness" is not a true stratigraphic thickness. Maybe it's exposure distance along the river?

If a scale is present on a strat section/column, it implies true thickness. However, the 12,000 foot section may be a composite section where workers have compiled sections from different parts of the canyon to form one complete section, or they've constructed a section by taking the thickest or average thicknesses for each unit to form a generalized section of the Supergroup.

Or a better explanation might be that the scale in post 82 is in meters rather than feet.

Mucho kudos to roxrkool, for doing all the work to dig up the information, diagrams, and references. Many more POTM's should be coming your way, but that would mean we're again getting into the "roxrkool posts again, gets POTMed again" situation. Maybe you should get a GMOAPOTM (grand mother of all POTM) when this topic is concluded.

Thanks, moose. No more POTMs means less pressure in the future. :) Really, though, the entire thread is good because of all the participants.
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edge
Member
Posts: 4466
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.2


Message 89 of 282 (296402)
03-17-2006 10:16 PM
Reply to: Message 87 by jar
03-17-2006 8:42 PM


Re: What sandstone???????
Remember, at this moment what is today the Vishnu Schist was still but sand and sandstone and the intrusions were still just magma.

Actually, the way a geologist would read the section would be that the sandstone was already a schist before the limetone was deposited.

This actually plays to your hand, jar. It adds just another step to the whole story. The Vishnu sediments had to be metamorphosed and folded prior to the Bass depostion. This is heralded by the presence of a major disconformity. Look at the section closely.

And, no, I would say that the magma has long cooled before Bass time.


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 Message 87 by jar, posted 03-17-2006 8:42 PM jar has responded

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 Message 90 by jar, posted 03-17-2006 10:30 PM edge has responded

  
jar
Member
Posts: 30934
From: Texas!!
Joined: 04-20-2004


Message 90 of 282 (296405)
03-17-2006 10:30 PM
Reply to: Message 89 by edge
03-17-2006 10:16 PM


Re: What sandstone???????
Okay.

Then more questions from the laity.

Actually, the way a geologist would read the section would be that the sandstone was already a schist before the limetone was deposited.

So, how do we turn sandstone into schist?

This is heralded by the presence of a major disconformity. Look at the section closely.

So a couple questions.

First, what is a disconformity?

And, no, I would say that the magma has long cooled before Bass time.

Cooled enough to have become granite?

Can you help explain to someone as slow as I am what needs to happen to change the sandstone to schist and the magma to granite?


Aslan is not a Tame Lion
This message is a reply to:
 Message 89 by edge, posted 03-17-2006 10:16 PM edge has responded

Replies to this message:
 Message 91 by edge, posted 03-17-2006 10:55 PM jar has responded

  
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