Talk:Callander Bay
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[edit] Geology
(Copied from talk page of User:Geologyguy)
Is Callander Bay an ancient caldera? It includes nepheline syenites, carbonatite, aegirine, amphibole, analcime, apatite, barite, biotite, calcite, cancrinite, chalcopyrite, chlorite, diopside, dolomite, fluorite, garnet, hematite, kaersutite, magnetite, muscovite, nepheline, olivine, perthite, pyrite, pyroxene and pyrrhotite. Black Tusk 05:23, 24 September 2007 (UTC)
- This page indicates that there are volcanic pipes at Callander Bay. Nepheline syenite and carbonatite would certainly be associateD with igneous activity (intrusive and extrusive, respectively), but not necessarily calderas - I have never heard of a documented carbonatite or alkalic-complex caldera. Most of those other minerals could be found in at least trace amounts in any igneous rock. A few (diopside, chlorite, garnet) are more typical of metamorphics, and obviously there are some that look like hydrothermal mineralization (barite, calcite, fluorite, pyrite, pyrrhotite). So I doubt very much if that list came from a single rock - it is likely to represent various rocks in the area. So - volcanic? yes, some is likely. Caldera? no evidence. A caldera is really a structural thing more than a petrologic thing, and given the many changes the rocks at Nipissing have undergone, I wouldn't be surprised if the evidence had been eradicated. One might look for circular or sub-circular features in the old rocks on the scale of 50-100 km. I don't think the mineralogy can definitively tell you whether or not it is a caldera. Cheers Geologyguy 13:52, 24 September 2007 (UTC)
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- Callander Bay is 3 km in diameter. The site here says: At the extreme east of Lake Nipissing is a circular feature that resembles a caldera. The minerials I listed above are found at Callander Bay. Black Tusk 14:02, 24 September 2007 (UTC)
- Clearly the statement at that link is based on nothing more than a circular shape on a Landsat image - definitely not enough to infer a caldera in my opinion. There are many circular features in the Canadian Shield that are remnants of impact features. One would have to look at the rocks to see if the circular margin of the lake is related to an impact, volcanic features (crater, caldera), glacial action, wave action, or simply chance. Cheers Geologyguy 15:59, 24 September 2007 (UTC)
- Have a look at [1] and WANAPITEI LAKE IMPACT CRATER for more on the subject. LeadSongDog 17:14, 24 September 2007 (UTC)
- I know what a impact crater is. How old would Callander Bay and the Manitou Islands be if they're volcanic pipes? They must have formed during the same period. Black Tusk 17:23, 24 September 2007 (UTC)
- Have a look at [1] and WANAPITEI LAKE IMPACT CRATER for more on the subject. LeadSongDog 17:14, 24 September 2007 (UTC)
- Clearly the statement at that link is based on nothing more than a circular shape on a Landsat image - definitely not enough to infer a caldera in my opinion. There are many circular features in the Canadian Shield that are remnants of impact features. One would have to look at the rocks to see if the circular margin of the lake is related to an impact, volcanic features (crater, caldera), glacial action, wave action, or simply chance. Cheers Geologyguy 15:59, 24 September 2007 (UTC)
- Callander Bay is 3 km in diameter. The site here says: At the extreme east of Lake Nipissing is a circular feature that resembles a caldera. The minerials I listed above are found at Callander Bay. Black Tusk 14:02, 24 September 2007 (UTC)
I definitely do not know for certain, but Lake Nipissing appears to lie within the Grenville Province, so I would bet that the igneous rocks are related to the Grenville orogeny, 1.0 to 1.3 Ga. Cheers Geologyguy 18:35, 24 September 2007 (UTC)
- It appears from this and others that Callander Bay is (just barely) inside the Britt domain, bordering the Kiosk. If so, it's 1.07-1.04 Ga (vice 1.00 for Kiosk) per this. If you can get hold of Currie's 1971 paper, it may shed more light.LeadSongDog 21:08, 24 September 2007 (UTC)
- One of the 5 named granite batholiths in the North Bay area appears to be about 1244 million years old (the Mullock batholith) [2]. Black Tusk 21:43, 24 September 2007 (UTC)
- Found the Ferguson/Currie paper at NRCanLeadSongDog 22:09, 24 September 2007 (UTC)
- Is it possible the pipe might be the deep erosion of a maar forming a diatreme? Black Tusk 23:24, 24 September 2007 (UTC)
- A diatreme is a pipe, but you cannot tell without looking at the rocks to see if there is breccia, and finding other evidence of great vertical extent. A maar is not typically something that occurs at the top of a diatreme, or even a more standard volcanic pipe - it is the result of a shallow hydrothermal explosion, essentially a bursting of a shallow bubble, usually hot water & steam, sometimes gas, occasionally magma. Most maars are significantly smaller than the 3-km diameter you have here. Also, since maars are thin surface features, it would not be expected that one would survive all the time since the Grenville event - few maars are known that are older than a few million years. Cheers Geologyguy 15:29, 25 September 2007 (UTC)
- Well, it must be part of a larger volcanic system that has since been eroded away if it was formed during the Paleozoic period. The only maar-like volcano known in Canada appears to be in the Wells Gray-Clearwater Volcanic Field.[3] Black Tusk 15:35, 25 September 2007 (UTC)
- Do diatreme contain alkaline? Black Tusk 16:28, 26 September 2007 (UTC)
- Well, it must be part of a larger volcanic system that has since been eroded away if it was formed during the Paleozoic period. The only maar-like volcano known in Canada appears to be in the Wells Gray-Clearwater Volcanic Field.[3] Black Tusk 15:35, 25 September 2007 (UTC)
- A diatreme is a pipe, but you cannot tell without looking at the rocks to see if there is breccia, and finding other evidence of great vertical extent. A maar is not typically something that occurs at the top of a diatreme, or even a more standard volcanic pipe - it is the result of a shallow hydrothermal explosion, essentially a bursting of a shallow bubble, usually hot water & steam, sometimes gas, occasionally magma. Most maars are significantly smaller than the 3-km diameter you have here. Also, since maars are thin surface features, it would not be expected that one would survive all the time since the Grenville event - few maars are known that are older than a few million years. Cheers Geologyguy 15:29, 25 September 2007 (UTC)
- Is it possible the pipe might be the deep erosion of a maar forming a diatreme? Black Tusk 23:24, 24 September 2007 (UTC)
- Found the Ferguson/Currie paper at NRCanLeadSongDog 22:09, 24 September 2007 (UTC)
- One of the 5 named granite batholiths in the North Bay area appears to be about 1244 million years old (the Mullock batholith) [2]. Black Tusk 21:43, 24 September 2007 (UTC)
[edit] Age
Hey Black Tusk - I don't think the cited reference indicates Paleozoic as the age; I read it as indicating a Grenville timing, that is, Proterozoic - isn't it? Cheers Geologyguy 16:33, 26 September 2007 (UTC)
- Well, the Ferguson/Currie paper LeadSongDog found was Cambrian and Paleozoic periods, however I can't seem to get into the site now. But if it's Proterozoic age, I will change it. Black Tusk 17:12, 26 September 2007 (UTC)
- I can't get into that Ferguson-Currie link either, I was going by the footnoted reference [4]. I definitely do not know what it is, so go by whatever your refs say. Cheers Geologyguy 19:36, 26 September 2007 (UTC)
- I'll change it to Proterozoic because your reference seems to be the only one that works. Are there any more volcanic pipes in the North Bay region? There appears to be one west of the Manitou Islands but doesn't give its name.[5] Black Tusk 20:12, 26 September 2007 (UTC)
- It's most likely Proterozoic because the majority of carbonatites are Proterozoic or Phanerozoic in age. Black Tusk 02:12, 28 September 2007 (UTC)
- Great, thanks for doing all that research. Cheers Geologyguy 15:09, 28 September 2007 (UTC)
- It's most likely Proterozoic because the majority of carbonatites are Proterozoic or Phanerozoic in age. Black Tusk 02:12, 28 September 2007 (UTC)
- I'll change it to Proterozoic because your reference seems to be the only one that works. Are there any more volcanic pipes in the North Bay region? There appears to be one west of the Manitou Islands but doesn't give its name.[5] Black Tusk 20:12, 26 September 2007 (UTC)
- I can't get into that Ferguson-Currie link either, I was going by the footnoted reference [4]. I definitely do not know what it is, so go by whatever your refs say. Cheers Geologyguy 19:36, 26 September 2007 (UTC)
