BigGuy Posted March 8, 2015 Share Posted March 8, 2015 (edited) Since the weather was warm today we did a day trip from Springdale, Arkansas to a stromatolite reef north of us near the Missouri border. The temperature reached 60 but there was still some snow and ice. Since Billie and I are lapidary enthusiast, I cut a few pieces we found. The striated patterns are beautiful and since the masses are preserved in silica (chert) they will take a high polish. We found some nice specimens also. Stromatolites are laminated structures built by blue green algae also called cyanobacteria, one of the simplest and earliest known life forms. Basically, each layer of algae contains sticky cells that trap sediment when it is washed over algae’s surface. As sediment accumulates, the algal layer grows through and over the sediment to the top to trap more sediment. Since blue-green algae needs sunlight for photosynthesis, stromatolites are restricted to shallow water within the photic zone. Fossil stromatolites are preserved in the Ordovician age Cotter Formation . Edited March 8, 2015 by BigGuy 1 Link to comment Share on other sites More sharing options...
Auspex Posted March 8, 2015 Share Posted March 8, 2015 Very, very nice! I especially appreciate the in situ view; we don't get to see this structure 'in the wild' very often. "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
RJB Posted March 8, 2015 Share Posted March 8, 2015 Amazing what mother nature can do! Nice stuff. RB Link to comment Share on other sites More sharing options...
xonenine Posted March 8, 2015 Share Posted March 8, 2015 excellent trip report and photos, thanks "Your serpent of Egypt is bred now of your mud by the operation of your sun; so is your crocodile." Lepidus Link to comment Share on other sites More sharing options...
erose Posted March 8, 2015 Share Posted March 8, 2015 That is really a great little re[port. Site photos, specimen photos and then the polished sections. Well done. Link to comment Share on other sites More sharing options...
Jeffrey P Posted March 8, 2015 Share Posted March 8, 2015 Beautiful specimens and nice photos. Your report reminds me there is a wonderful Upper Cambrian stromatolite reef just west of Saratoga Springs, NY. This site is a designated landmark so no collecting is permitted, but next time I'm in the area I'll try to get some photos and post them. These are quite lovely. Thanks. I'm sure you'll enjoy them. Link to comment Share on other sites More sharing options...
lfsxdth Posted March 8, 2015 Share Posted March 8, 2015 Great post. Thanks for sharing. Link to comment Share on other sites More sharing options...
Scylla Posted March 8, 2015 Share Posted March 8, 2015 If you want to collect some stromatolites in NY, just go to Herkimer, they come with nice decorative quartz crystals too. Ours don't take that nice polish though. Thanks for showing them to us. Link to comment Share on other sites More sharing options...
JustPlainPetrified Posted March 8, 2015 Share Posted March 8, 2015 That in situ photo is great! Link to comment Share on other sites More sharing options...
Ludwigia Posted March 8, 2015 Share Posted March 8, 2015 Great little report and a nice shiny polishing job! Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
jcbshark Posted March 8, 2015 Share Posted March 8, 2015 Great pics and finds! Thanks for sharing Every once in a great while it's not just a big rock down there! Link to comment Share on other sites More sharing options...
BobC Posted March 9, 2015 Share Posted March 9, 2015 Wow--that is awe-inspiring. To even imagine that we are looking at something that was more or less the beginning of life as we know it on this planet is just astounding. Thanks for posting. Link to comment Share on other sites More sharing options...
Auspex Posted March 9, 2015 Share Posted March 9, 2015 The oldest are in Western Australia: 3.5 billion years old! Australia also has the youngest: Shark Bay, at low tide. This is a pretty persistent form of life "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
PietAlberts Posted May 28, 2015 Share Posted May 28, 2015 (edited) I recently started reading up on stromatolites after I learnt that we have stromatolite formations and living tufa cyanobacteria colonies in the rocky beaches of Port Elizabeth, South Africa. The cyanobacteria found here are unique, their habitat is the semi-freshwater pools where freshwater from springs meet the sea where they line and grow on the submerged surfaces of the pools. The stromatolites have irregular forms and my observation is that quite often they are concave plates opposed to the more well known dome shaped forms. Here is a photo I took at Schoenmakerskop this morning. The cyanobacteria colony is in the centre and the stromatolite formations in the background I was wondering how it is that the reefs are often arranged in straight and parallel lines, some drama must have played off here over millions of years! Here is an example of the convex shaped plates (How old are they?) Edited May 28, 2015 by PietAlberts Link to comment Share on other sites More sharing options...
Auspex Posted May 28, 2015 Share Posted May 28, 2015 Very interesting! Thank you "Life finds a way" "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
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