Hoyt stromatolites

| 14 Comments

Photograph by James Kocher.

Photography contest, Honorable Mention.

Kocher_HoytStromatolites.jpg

Stromatolites in outcrop, cryptozoon proliferum (Hall, 1882). Hoyt limestone, late Cambrian (~500 Ma). Lester Park, Saratoga Springs, N.Y., July, 2012.

14 Comments

Has someone been using a hedgehog as a scouring pad?

We have some younger (c. 145 Ma) “relatives” in England:

http://www.southampton.ac.uk/~imw/F[…]l-Forest.htm

Stromatolites, thrombalites, fossil forest with the soil in place, imprints of halite and gypsum, evaporitic beds …

What is for a GEOLOGIST not to like? (YEC Flood “geologist”, not so much.)

Alan Bates

Thanks for the oxygen, oh builders of stromatolites.

Glen Davidson

I don’t live terribly far from there… about 1 hour. You’ve inspired me to make the trip. I’ve always wanted to see stromatolites. Had no idea they were so close. I see though that these are Cambrian, not the really ancient ones so important for the record of earliest life. Can anyone comment on the significance of Cambrian stromatolites for our understanding of evolutionary history? What I’ve found on-line hasn’t been super informative.

There is a bay on the west coast of Australia (Shark Bay, I think) where living examples of this amazing life, lives on:)

Yep, Shark Bay is right. Shark Bay is only, oh, 700 miles or so from where I live. I’ve actually seen them there, although it was a very long time ago, and I was too young to be impressed. They look, as I recall, like globular rocks, piled into a sort of moraine, lying in shallow water.

We need them more than ever, it seems.

These patterns “look designed” to me.

Yet there seems to be a good natural explanation for them.

But of course, if someone has a really good, rigorous scientific experiment to suggest, that will give a positive result if they were “designed by an intelligence”, I’m will to try it.

Creationists, I’m willing to listen. What is your specific explanation, and how can we test it?

For a second there… I thought the title was “Holy Stromatolites”

bigdakine said:

For a second there… I thought the title was “Holy Stromatolites”

Good … I’m not the only one …

bigdakine said:

For a second there… I thought the title was “Holy Stromatolites”

Me too. If you learned to read using flash-cards and sight-words rather than phonics you tend to recognize patterns rather than reading a string of letters in order (at least that’s the case with me). In this case you see a word with an Ho and a y is in there, your mind doesn’t bother to process past that and decides it’s Holy instead of Hoyt. I experience this all the time except I usually see words like this (on billboards strangely enough) as expletives and have to take a second look only to realize my mind is playing tricks on me.

That’s probably what Robin (Batman’s sidekick) would call them!

Sylvilagus said:

I don’t live terribly far from there… about 1 hour. You’ve inspired me to make the trip. I’ve always wanted to see stromatolites. Had no idea they were so close. I see though that these are Cambrian, not the really ancient ones so important for the record of earliest life. Can anyone comment on the significance of Cambrian stromatolites for our understanding of evolutionary history? What I’ve found on-line hasn’t been super informative.

If you go to the Wiki link in the figure legend, they are evidence for early photosynthesis, and oxygen production. There are questions. If there were photosynthetic prokaryotes as early as 3.4 billion years ago when did the oxygen concentration of the atmosphere change significantly? Oxygen levels seem to have become significant around 2.4 billion years ago. There is also the suggestion that there was a decline in the population that they attribute to the evolution of grazers by 1 billion years ago. Were these grazers multicellular or protozoan? How does competition from the Ediacaran fit into this scenario? When did oxidative phosphorylation evolve? It sounds like cyanobacteria produced the oxygen that allowed the evolution of oxidative phosphorylation, and the symbiosis with eukaryotes (evolution of mitochondria) that caused their own demise.

harold said:

These patterns “look designed” to me.

Yet there seems to be a good natural explanation for them.

But of course, if someone has a really good, rigorous scientific experiment to suggest, that will give a positive result if they were “designed by an intelligence”, I’m will to try it.

Creationists, I’m willing to listen. What is your specific explanation, and how can we test it?

And the reply was…[sound of crickets chirping]

What a surprise. No, not really.

Sylvilagus said:

I don’t live terribly far from there… about 1 hour. You’ve inspired me to make the trip. I’ve always wanted to see stromatolites. Had no idea they were so close. I see though that these are Cambrian, not the really ancient ones so important for the record of earliest life. Can anyone comment on the significance of Cambrian stromatolites for our understanding of evolutionary history? What I’ve found on-line hasn’t been super informative.

IMHO, Cambrian stromatolite colonies, and their associated faunas, represent the first true metazoan/protist “reef” ecosystems. Corals do not become abundant as reef-formers until Ordovician-Devonian time. Once sufficient metazoan heterotrophs evolved in the early to middle Cambrian, stromatolites became the “salad bars” of the oceans, and their frequency in the geological column drops sharply. From the early Paleozoic Eon to Modernity, stromatolites become predominantly constrained to brackish (hypersaline) environments (though not completely). A prime example (modern) is the famous Shark Bay, Australia locality. It should be noted that Archeocyathids (extinct problematic sponge-like organisms), Porifera (sponges), and stromatolites did form “reefs” earlier in Cambrian time, but these assemblages are not as widespread as those of middle and late Cambrian strata. Also, stromatolite reef-like groups mostly occurred in the Proterozoic Eon (Pre-Cambrian), and there is no hard evidence of any contemporaneous and/or diverse metazoans existing with them.

Lester Park is pretty neat, but the exposures are probably only 0.1 acre in size. The Cryptozoon colonies are fantastically detailed up close. This time of year might be better to see the stroms, as vegetation is minimal (unless Saratoga Springs area has snow cover!). About 1/2 mile south of the park, a “tourist trap” called Petrified Sea Gardens used be open (for a fee) to access additional exposures. I was with the wife and daughter when I visited the area in July; we were on the way to visit friends in New Hampshire. I did not have time to check out the area as much as I would have liked. So many stromatolites, so little time…

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This page contains a single entry by Matt Young published on January 14, 2013 12:00 PM.

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