DPS Ammonite Posted April 22, 2017 Share Posted April 22, 2017 This is a piece of opalized wood from the late Miocene Neroly Formation near Antioch, CA. AKA Antioch Wood. What is the cause of the herringbone or chevron growth rings? Did the tree grow that way or was the wood compressed before it was fully mineralized? I found similar wood from Late Miocene formations in the Berkeley Hills. I also have seen similar wood from the Hell's Canyon area in Idaho/Oregon. Has anyone found wood with a similar pattern elsewhere? Any idea what type of wood this is? The field of view in the photo is about 0.6 inches across. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Rockwood Posted April 22, 2017 Share Posted April 22, 2017 I've seen a similar thing in modern wood. It's usually older trees. I think it may be a response to stress. Link to comment Share on other sites More sharing options...
doushantuo Posted April 22, 2017 Share Posted April 22, 2017 i once posted this,to promote understanding of woody structures http://www.thefossilforum.com/index.php?/topic/72590-cant-see-the-treesbut-i-sure-see-the-wood/#comment-764227 1 Link to comment Share on other sites More sharing options...
supertramp Posted April 22, 2017 Share Posted April 22, 2017 11 hours ago, DPS Ammonite said: What is the cause of the herringbone or chevron growth rings? Might it be that growth rings have been affected by some branch nodes just above or below the section? https://www.google.it/search?q=tree+rings+growth+knots&rlz=1C1AOHY_itIT708IT708&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiL9Z_WnbjTAhXNbVAKHdK-A0oQ_AUICCgB#tbm=isch&q=tree+rings+growth+&imgrc=dqBQ7_JmDZvYsM: https://www.google.it/search?q=tree+rings+growth+knots&rlz=1C1AOHY_itIT708IT708&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiL9Z_WnbjTAhXNbVAKHdK-A0oQ_AUICCgB#tbm=isch&q=tree+rings+growth+&imgrc=jYVJE7QZDgJ_jM: https://www.google.it/search?q=tree+rings+growth+knots&rlz=1C1AOHY_itIT708IT708&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiL9Z_WnbjTAhXNbVAKHdK-A0oQ_AUICCgB#tbm=isch&q=tree+rings+growth+&imgrc=Z4mbVaQ4AtxbOM: ciao Link to comment Share on other sites More sharing options...
abyssunder Posted April 22, 2017 Share Posted April 22, 2017 Try to compare it with the wavy pattern of Pseudotsuga annual rings. " Fragments of petrified wood are common in the Neroly sediments. Mr. Dougherty, formerly of the University of California, identified one specimen as a dicot and another as larch (Larix) or Douglas fir (Pseudotsuga). " - A.S. Huey. 1948. Geology of the Tesla quadrangle, California. Bulletin 140. 1 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
DPS Ammonite Posted April 23, 2017 Author Share Posted April 23, 2017 Thank you everyone for your help. The most similar wood structures came from the reference mentioned by doushanuto: figure 10:22 from Fritz Hans Schweingruber's "Wood Structure and Environment." I tend to think the folded wood growth rings in my piece are from compression since the folds sort of occur in a plane that could be created from compression in one direction. If I find a piece of wood with a complete circle of growth rings that are folded in all directions then I might be convinced that the tree grew with chevron growth rings. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Rockwood Posted April 23, 2017 Share Posted April 23, 2017 It does take huge pressure to fold mineralized wood. It folds much easier when it's green though,and if you've ever pinched a saw bar in a large tree you know they can produce considerable pressure. Link to comment Share on other sites More sharing options...
ynot Posted April 23, 2017 Share Posted April 23, 2017 I have cut a lot of firewood and see that type of folding under big branches quite often. Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
abyssunder Posted April 23, 2017 Share Posted April 23, 2017 I thought you wanted to find out the genus or species name for this petrified wood trunk piece, AKA Antioch Wood. " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
doushantuo Posted April 23, 2017 Share Posted April 23, 2017 it's not even inconceivable that those are chevron folds,caused by Miocene compressional tectonics in the Antioch region Link to comment Share on other sites More sharing options...
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