Need help with Stromatolites

[0lderthandirt]

NW Arizona,  Mississippian,  redwall limestone, Mooney member. 

I need your help determining what if any,  of these examples are Stromatolites. From what I've read they should be all around me but nothing on my property seems to match pictures online. I numbered the three smaller rocks and the fourth was much larger and outside. Are any of these layered rocks Stromatolites?  Thank you and sorry about the sideways view, top and bottom cut off when it was rotated. 

[Miocene_Mason]

I don't see any obvious stromatolites here (although the rock under N looks suspicious), and in the rocks you sent me there was also no stromatolites (although I thought so for a second on one, which I know think to be a holdfast, that will be a thread soon) your looking for the right features though, a banded appearance.

[0lderthandirt]

Well i just stepped outside and the first rock i picked up was this,  looking much more like the pictures of stroms, what do you think? 

Not sure why the picture rotated

[Miocene_Mason]

That does look like a stromatolite, and that would be my guess. There are however some geological processes that can create similar structures so I'm going to wait for the opinion of others.

[Wrangellian]

If they are stroms, they appear to be 'chertized' (silicified) which would obliterate some finer detail, so it's hard to tell. I too will defer to others with more knowledge on that formation and experience in finding stroms in it.

[0lderthandirt]

I'm running out of layered rocks. I may have to accept the idea that I just don't have Stromatolites on my property

[Miocene_Mason]

24 minutes ago, 0lderthandirt said:

I'm running out of layered rocks. I may have to accept the idea that I just don't have Stromatolites on my property

Never! I'd keep an eye out, they are probably there. I seem to find the best things when I'm not looking for them, maybe it will be the same for you.

[0lderthandirt]

Yeah I probably trip over a pile of them every time I walk up the hill and I just don't realize what they are! Or like yesterday I flipped this rock over and simply walked away without further examination

[Wrangellian]

What is in that hole?

 

About the stroms, what do the pics look like in the reference you have?

[0lderthandirt]

Haha that rock took two hands to flip over, pretty good size and had holes all through it. One hole must've led down to that big ugly spider cause that would've been the only way in or out for him

[0lderthandirt]

14 minutes ago, Wrangellian said:

What is in that hole?

 

About the stroms, what do the pics look like in the reference you have?

I looked at quite a few pictures today,  I did a search here and there was a picture on http://www.fossilmuseum.net/Tree_of_Life/Stromatolites.htm that showed distinctive layers that reminded me of a rock I found about a week ago, can't find it now though. So to answer your question I think most of the strom pictures I looked at were from past postings here,  I should've kept them but I thought after all that I knew what I was looking for. 

[doushantuo]

[Wrangellian]

13 minutes ago, 0lderthandirt said:

I looked at quite a few pictures today,  I did a search here and there was a picture on http://www.fossilmuseum.net/Tree_of_Life/Stromatolites.htm that showed distinctive layers that reminded me of a rock I found about a week ago, can't find it now though. So to answer your question I think most of the strom pictures I looked at were from past postings here,  I should've kept them but I thought after all that I knew what I was looking for. 

Oh, I misunderstood - you never saw any pics of what the ones from your site look like, just a text reference that they can be found there?

[0lderthandirt]

Thank you @doushantuo great information

[doushantuo]

Kent & Rawson mention the presence of stromatolitic boundstone in the Redwall,BTW

[0lderthandirt]

There was this picture from grand canyon park,  close to me, but wasn't more specific than that

[0lderthandirt]

18 minutes ago, doushantuo said:

Kent & Rawson

Are they showing Stromatolites in the Mooney  Falls member ? Looks like they are in Horseshoe Mesa, but  kinda blurry

[doushantuo]

Any Carboniferous sub-/intertidal environment might show stromatolites or some form of laminar microbialite.aggrading cyanophycean buildup,or regular alternations of granulometry that might look like stromatolites(at least under the microscope).

The Visean of Belgium might be a good example

[doushantuo]

LepotNATURE2008Stromatolite.pdf

 

I'd warn against too simplistic assumptions about stromatolites,BTW

[0lderthandirt]

13 minutes ago, doushantuo said:

LepotNATURE2008Stromatolite.pdf

 

I'd warn against too simplistic assumptions about stromatolites,BTW

I'm learning that, thank you so much

[doushantuo]

I'll just list some relevant title pages of things i COULD post

 

 

[DPS Ammonite]

It is unlikely that your rocks are stromatolites. The reference by Kent & Rawson as posted by Doushantuo pointed out that the stromatolites were found in well cores (subsurface). Edwin McKee, (History of the Redwall Limestone of Northern Arizona GSA Memoir 114), pointed out that stromatolites have been reported (on the surface) from the Mooney Falls Member but he found them only in the Whitmore Wash Member where they are locally common and others fossils are rare. McKee said that banded and layered chert nodules are common in the Mooney Falls Member and are formed when silica was deposited in areas with numerous fossils before they carbonate had hardened. McKee and I note that most of the chert nodules contain numerous molds of many fossils including bryozoan and crinoids. In the Payson area the banded white and grey chert is known as "Zebra Agate".

 

Do your rocks contain fossil molds?  

 

@Arizona Chris may have additional information since he collects in the Redwall Fm.

[doushantuo]

Given the fact that The Redwall is also an aquifer, there should be something more on the Redwall

edit:

like

carb vap 2010.pdf

[0lderthandirt]

11 minutes ago, DPS Ammonite said:

Do your rocks contain fossil molds?  

Yes,  almost all have some sort of fossil

[Arizona Chris]

Chert banding related to the conditions of deposition result in the white banding you see in the Redwall and are not specifically caused by cyanobacterial mats or stromatolites.  However - the right specimen is a very common fossil in the Redwall, which we have found many examples here in northern Arizona.  Those are stromatoporoids and are mentioned quite often in McKee and Gutschick epochal memoir 114 on the Redwall, and we have sought out most of their localities to see such stroms ourselves in the field.  Some of them are quite large - covering many square feet of strata in the outcrop.  So far, we have never found any stromatolites in the Redwall in the Payson Area, but algal mats can be occasionally be seen in some facies.  A common non fossil you will also find that looks similar is the zebra jasper.  It is white/grey bands in a porcelain like chert and has lapidary value at best.