Preferential Flowpaths & The Origin of Limestones Caves

[hydrology_joe]

From the How are caves formed thread...

I suspect the original poster's question has been answered. This is the speleology section, and his question was well-placed. All is good. So why not now break this off into a new thread and fire up the equations and jargon? I doubt anyone would mind a good debate over cave science. This is interesting stuff.
Keith Christenson

Fair enough, Keith Christenson, I'll post the great cave type chart supplied by Hydrology_Joe in a new thread and ask him some questions about it if I can figure out how to enlarge the chart and transfer it.

Here is the new thread and the chart...

[Spike]

Joe

When reading through your paper from JCK I noticed you said there were over 5000 cave maps were available for the study. However table 1 lists a little over 2000 maps available, which is about the number of maps on file currently. I take it that 5000 is a typo? Easy to do since there were over 5000 caves on file at the time of publication. Also concerning anastomosies caves forming in the Salem Plateau, I would be interested in which caves where used. Most caves in the area I would consider anastomosic do not appear to form from diffuse recharge but from flood water injection into algal laminates, similar to the Hannibal Model but with out the joint controlled development.

Spike

[hydrology_joe]

When reading through your paper from JCK I noticed you said there were over 5000 cave maps were available for the study. However table 1 lists a little over 2000 maps available, which is about the number of maps on file currently. I take it that 5000 is a typo? Easy to do since there were over 5000 caves on file at the time of publication. Also concerning anastomosies caves forming in the Salem Plateau, I would be interested in which caves where used. Most caves in the area I would consider anastomosic do not appear to form from diffuse recharge but from flood water injection into algal laminates, similar to the Hannibal Model but with out the joint controlled development.
Spike

Yes, the 5000 was a typo that managed to slip pass the internal and peer reviewers before it was published.

I can compile a list of caves used, but that will require me getting at my home computer to pull from.

The actual postulation for the increased number of anastomotic caves within the Salem is the combination of recharge through sinking streams and relatively horizontal bedding surfaces. (2nd column 2nd row of Palmer, 1991 - Figure 25) The floodwater injection is an interesting method for that area and could be true. Considering the geomorphic history and geologically recent downcutting (Bretz, 1965), I don't know if the host rock would have been exposed enough at the time of cave development to be subjected to floodwater injection as the Hannibal Karst Area was. You bring up a great point for future research.

A key thought to remember is that the scope of work was to develop a metric by which existing caves could be classified into the Palmer, 1991 matrix. Many secondary projects sprang up throughout the project that could not be investigated because of the original scope of the work. Since my work developed & tested the metric, it can be now applied to specific caves or areas to target the probable recharge type and specific research can go from there.

[Stelios Zacharias]

Most caves in the area I would consider anastomosic do not appear to form from diffuse recharge but from flood water injection into algal laminates, similar to the Hannibal Model but with out the joint controlled development.

I have recently helped translate the UIS cave survey symbols into Greek and one of the last symbol blocks is "anostomosen / karren" in the english version. I found "Karren", but never found what anostomosen refers to, leaving the translation incomplete.

I would be grateful if you could point me in the right direction to learn what the meaning of the word "anastomosic" is.

Many thanks,
Stelios Zacharias

[Baazalung]

An anastomosis is an artificially created connection between two structures, organs or spaces. It most commonly refers to a connection which is created surgically between two tubular structures, such as a transected blood vessel or loop of intestine. For example, when a segment of intestine is resected, the two remaining ends are sewn or stapled together(anastomosed), and the procedure is referred to as an intestinal anastomosis.

You could relace it with: connected, joined etc.

This is merely my opinion, I have never studied Karstology.

"opinion above is mine, not Petzl's" <-- Like another user says

[Teresa]

From AGI glossary of geology:
anastomosis: (a) braiding (b) a product of braiiding esp. an interlacing network of stream channels.

anastomosis tube: One of the many small irregular repeatedly interconnected solution tubes, commonly found along bedding planes.

anastomosic cave: A cave consisting of braided interconnected tubular passages. Also network or spongework cave.

[Teresa]

The actual postulation for the increased number of anastomotic caves within the Salem is the combination of recharge through sinking streams and relatively horizontal bedding surfaces.

This contradicts your previous concept in the other thread that mechanical separations are not needed for cave formation.

The floodwater injection is an interesting method for that area and could be true. Considering the geomorphic history and geologically recent downcutting (Bretz, 1965), I don't know if the host rock would have been exposed enough at the time of cave development to be subjected to floodwater injection as the Hannibal Karst Area was.

I don't know of anyone who takes the 1965 Bretz Geomorph History of Missouri very seriously any more, as it is based firmly on the pre-Strahler geomorphical theory of Wm Morris Davis, which has been pretty well debunked these days. (Just to note that hydrology_joe's cite is not to Caves of Missouri-- the whole peneplain/rejuvenation thing fails for lack of a mechanism under tectonic theory. )

While the floodwater injection model might be reasonable for caves further to the north, and within the southern drainage shadow of glaciation, and/or the Missouri River valley, such is not the case in the Salem Plateau, which rises rather precipitously from the Missouri River breaks. If Spike is talking about localized groundwater flooding (say after a 5 inch rain in 24 hours) I concur, but that does not require the local host rock to be 'exposed' any more than it is presently.

I have some reservations about the explanation about the development of cave passage along algal laminates (read stromatolites and cryptoozoan reefs) in Missouri. This seems to occur only where the algal reef structures have been silicified, not where the same structures remain as carbonates. Obviously the break in lithology gives water a 'mechanical' crack or passage for water to enter and do its thing, but the same thing occurs along chert nodule strings in higher Mississippian limestones, along sandstone/dolomite contacts, and other lithological unconformities.

I would be interested in knowing if there are extensive caves along non-silicified stromatolites/cryptoozoan reef structures. I've never encountered any--though I've seen plenty of them in roadcuts.

[Spike]

I couldn't disagree more concerning the silicified algal structures. If one closely inspects the phreatic features of the caves in the Gasconade Dolomite of central Missouri you will find that they are associated with non-silicified algal laminates. However later down cutting often intersects silicified algal stuctures giving the impression that the cave formed perched above this zone. If that were the case then I wold expect to see phreatic dissolution features at this zone rather than several meters higher in the section. On a side note the contact caves in Stone County Missouri typicall form at the contact of the Pearson and Reed Springs well below the silicified zone with domes stoping upward into the chert.

Spike

[hydrology_joe]

The actual postulation for the increased number of anastomotic caves within the Salem is the combination of recharge through sinking streams and relatively horizontal bedding surfaces.

This contradicts your previous concept in the other thread that mechanical separations are not needed for cave formation.

No! In the previous thread I was merely correcting the incorrect notion that mechanical seperations are necessary for cave formation. Caves can form without mechanical seperations or in orientations contradictory to mechanical seperations.

The floodwater injection is an interesting method for that area and could be true. Considering the geomorphic history and geologically recent downcutting (Bretz, 1965), I don't know if the host rock would have been exposed enough at the time of cave development to be subjected to floodwater injection as the Hannibal Karst Area was.

I don't know of anyone who takes the 1965 Bretz Geomorph History of Missouri very seriously any more, as it is based firmly on the pre-Strahler geomorphical theory of Wm Morris Davis, which has been pretty well debunked these days. (Just to note that hydrology_joe's cite is not to Caves of Missouri-- the whole peneplain/rejuvenation thing fails for lack of a mechanism under tectonic theory. )

Bretz's mechanism has been pretty thoroughly debunked. Although, while the mechanism is incorrect, the history and timeline are usable.

While the floodwater injection model might be reasonable for caves further to the north, and within the southern drainage shadow of glaciation, and/or the Missouri River valley, such is not the case in the Salem Plateau, which rises rather precipitously from the Missouri River breaks. If Spike is talking about localized groundwater flooding (say after a 5 inch rain in 24 hours) I concur, but that does not require the local host rock to be 'exposed' any more than it is presently.

Localized flood injection may be a factor, but I cannot imagine it being a regional factor. Most caves found in Missouri are exhumed by "recent" stream incision and the (limited) dating of stal in Missouri puts the regional cave ages much older than the exhumation.

[Teresa]

The actual postulation for the increased number of anastomotic caves within the Salem is the combination of recharge through sinking streams and relatively horizontal bedding surfaces.

This contradicts your previous concept in the other thread that mechanical separations are not needed for cave formation.

No! In the previous thread I was merely correcting the incorrect notion that mechanical seperations are necessary for cave formation. Caves can form without mechanical seperations or in orientations contradictory to mechanical seperations.

I still don't believe this, no matter how many times you repeat it. So let's leave it at that. Will not believe it until someone has some data showing fluid flow dissolution by thorough wetting of a porous permeable but unfractured limestone dissolving away the rock at a X rate compared to Y rate of a similar fractured limestone. As noted before, there are no massive unfractured limestones in Missouri, though there are plenty of exceedingly tight limestones which do not form caves, including quite a number with carbonate stromatolites (middle Cambrian, and Ordovician), and a fair number of massive dolostones. Magnesium matters. It changes the dissolution kinetics.

It's quite a leap from seeing a few examples of unexplainable things to making generalizations about how all (or most) caves are formed."

The floodwater injection is an interesting method for that area and could be true. Considering the geomorphic history and geologically recent downcutting (Bretz, 1965), I don't know if the host rock would have been exposed enough at the time of cave development to be subjected to floodwater injection as the Hannibal Karst Area was.

I don't know of anyone who takes the 1965 Bretz Geomorph History of Missouri very seriously any more, as it is based firmly on the pre-Strahler geomorphical theory of Wm Morris Davis, which has been pretty well debunked these days. (Just to note that hydrology_joe's cite is not to Caves of Missouri-- the whole peneplain/rejuvenation thing fails for lack of a mechanism under tectonic theory. )

Bretz's mechanism has been pretty thoroughly debunked. Although, while the mechanism is incorrect, the history and timeline are usable. [/quote]

I don't accept the history nor the timeline without the mechanism.

While the floodwater injection model might be reasonable for caves further to the north, and within the southern drainage shadow of glaciation, and/or the Missouri River valley, such is not the case in the Salem Plateau, which rises rather precipitously from the Missouri River breaks. If Spike is talking about localized groundwater flooding (say after a 5 inch rain in 24 hours) I concur, but that does not require the local host rock to be 'exposed' any more than it is presently.

Localized flood injection may be a factor, but I cannot imagine it being a regional factor. Most caves found in Missouri are exhumed by "recent" stream incision and the (limited) dating of stal in Missouri puts the regional cave ages much older than the exhumation.[/quote]

There is more stal dating out there of which you may not be aware. You may also not be aware that the researchers dating stal have an interesting selection method, depending upon what thesis they are exploring, and what access the caveowner allows to the scientist. While one obviously cannot have a stal which is older than the cave which contains it, most stal dates only go back to roughly Pleistocene time or younger. This is well within the range of usual cave ages of a few thousand to a couple of million years, and, with the exception of the glaciated areas, and outwash areas, no other significant geomorphological chages are postulated for the southern half of the state.

[hydrology_joe]

ARGH!

No! In the previous thread I was merely correcting the incorrect notion that mechanical seperations are necessary for cave formation. Caves can form without mechanical seperations or in orientations contradictory to mechanical seperations.

I still don't believe this, no matter how many times you repeat it. So let's leave it at that. Will not believe it until someone has some data showing fluid flow dissolution by thorough wetting of a porous permeable but unfractured limestone dissolving away the rock at a X rate compared to Y rate of a similar fractured limestone. As noted before, there are no massive unfractured limestones in Missouri, though there are plenty of exceedingly tight limestones which do not form caves, including quite a number with carbonate stromatolites (middle Cambrian, and Ordovician), and a fair number of massive dolostones. Magnesium matters. It changes the dissolution kinetics.

Pull the Palmer, 1991, Origin and Morphology of Limestone Caves paper and spend some time reading it. Dr. Palmer goes deeper into the dissolution kinetics than has been discussed here and does include Magnesium. I feel that no matter what I post, it isn't going to make a difference, so please go straight to the horse's mouth (so to speak).

It's quite a leap from seeing a few examples of unexplainable things to making generalizations about how all (or most) caves are formed."

Noone is making generalizations here. I was merely pointing out the oversight of mixing water corrosion as an important factor in cave formation (in the original thread) and the incorrect notion that mechanical separations for preferential flow are required to form caves. Mechanical separations are the most common preferential flowpath for the formation of caves, but they are not the only flowpath.

Bretz's mechanism has been pretty thoroughly debunked. Although, while the mechanism is incorrect, the history and timeline are usable.

I don't accept the history nor the timeline without the mechanism.

The history and timeline are documentable facts based on basic laws of geology (superposition, orginal horizontality, cross-cutting relationships) and geologic dating. Bretz's mechanism has changed, but the basic facts have not. If you want to ignore those, that is your loss.

[hydrology_joe]

Pull the Palmer, 1991, Origin and Morphology of Limestone Caves paper and spend some time reading it. Dr. Palmer goes deeper into the dissolution kinetics than has been discussed here and does include Magnesium. I feel that no matter what I post, it isn't going to make a difference, so please go straight to the horse's mouth (so to speak).

A better discussion on the formation of anastomotic & spongework caves (preferntial flow indifferent to mechanical seperations) is in Palmer, 1975, The Origin of Maze Caves, NSS Bulletin, vol 37 No 3 pp 56-76

[Teresa]

Pull the Palmer, 1991, Origin and Morphology of Limestone Caves paper and spend some time reading it. Dr. Palmer goes deeper into the dissolution kinetics than has been discussed here and does include Magnesium. I feel that no matter what I post, it isn't going to make a difference, so please go straight to the horse's mouth (so to speak).

A better discussion on the formation of anastomotic & spongework caves (preferntial flow indifferent to mechanical seperations) is in Palmer, 1975, The Origin of Maze Caves, NSS Bulletin, vol 37 No 3 pp 56-76

Considering that the 1991 Palmer paper is not freely available on the Net, nor by purchase from GSA (the publisher) and only available as a fulltext article from a place which requires one to be associated with some instittution to get hold of it, or if one happens to be a geology student somewhere with a library backlog of GSA Bulletins, the alternate probably is a good thing. A version of Dr. Palmer's paper on cave types is in the book Speleogenesis from the NSS, but has no dissolution kinetics, and just talks about groundwater types and their effects in causing different styles of caves. But where can one get NSS Bulletins from 30 years ago? Their online archive only goes back to 1996. I don't know too many people who were caving 30 years ago.

[Spike]

You can purchase the past bulletin from the NSS Bookstore for 5 bucks. Or see if your local grotto has a library.

[Pat Kambesis]

" I was merely pointing out the oversight of mixing water corrosion as an important factor in cave formation (in the original thread) and the incorrect notion that mechanical separations for preferential flow are required to form caves. Mechanical separations are the most common preferential flowpath for the formation of caves, but they are not the only flowpath."


Following are questions or need for more info - NOT criticisms on the current thread. Some examples might be beneficial for the discussion.

How about some examples of other types of flowpaths.

On the reference to mixing water corrosion - is the point that this type of dissolution does not require a flowpath in order to form cave or perhaps that the flowpath is not mechanical in nature?

If one considers all karst types, there are five elements that they all have in common in terms of their "karstification". One of those elements is
Porosity/permeability/fractures. The development of a mass transport system within any kind of rock requires a means for fluids to pass through the rock. This is accomplished by the existence of discontinuities in the inter- and intra- rock fabric. These include porosity, the pore spaces within the rock; permeability which is the connectivity of pore spaces and fractures (which include faults, bedding planes and other structural discontinuities.)

Perhaps this is what is meant by other flow paths?

And finally, on availability of reference material for any kind of scientific research and/or discussion - though the internet is certainly a great resource for finding such material, if one is serious about this kind of thing then one most also consider using library search systems too. There is still a lot of literature out there that is not available in the internet
but that is critical for understanding what topic is being pursued.

pk