pecopteris Posted January 20, 2013 Share Posted January 20, 2013 Hi everyone! SO... I placed my concretions in water for 3 days, and then froze them. I left them in the freezer for 1 week. I then proceeded to pull them out and give them like 5 or six taps each (W/ a metal hammer and the other part of the rock on concrete). But the fossils seemed 'soft' when I hit them, just rubbing material off on the ground.... I so far, haven't even been able to open one of my concretions am I doing something wrong?? -Pecopteris "PECO" (Pecopteris) - I specialize in Carboniferous fossils. I have a wide array of plants. In my collection at the moment: Ferns, Calamites, Syringodendron, Aspidaria and Sigillaria. Link to comment Share on other sites More sharing options...
AgrilusHunter Posted January 20, 2013 Share Posted January 20, 2013 Hi Pecopteris, From reading your post it sounds like you've only frozen and thawed your nodules a single time. Is this correct? If so I think that is the main prroblem. It can take many many freeze thaw cycles to 'pop' open the nodules. The outside of the nodules will often get softer during the process, sometimes flaking off completely. The process is definitely time consuming, you should expect to be freezing and thawing several times a week. Be patient and don't resort to the hammer until you actual start seeing a crack that wraps around the nodule. You can tell if the crack goes all the way through by squeezing the freshly thawed nodule, ones that are almost completely split will squeeze out some water from the crack. Hope this helps. "They ... savoured the strange warm glow of being much more ignorant than ordinary people, who were only ignorant of ordinary things." -- Terry Pratchett Link to comment Share on other sites More sharing options...
PetrolPete Posted January 20, 2013 Share Posted January 20, 2013 When I freeze/thaw my concretions the way I typically go about it is to soak them in water initially for a day, then I move the tray they are in, still with the water in it, into the freezer. I let it sit for 8 to 24 hrs (however long that particular freezer takes to freeze it), and once frozen, I thaw it out with warm water to try and shock the rock. After inspecting the concretions for cracks, I put them back in the freezer, and repeat the cycle again and again until they pop naturally. Sometimes it takes weeks or months to open them, but I've managed to only have a few bad breaks. You have to remember, the reason it works well is because it is a slow and gradual process. The fossil itself acts as a flaw in the rock for the rock to fail at, so if you go slowly, it is very likely for the water expansion to cause failure in the concretion along that surface. You might be able to get similar results if you hit it right, but it won't work as well as often in most concretions. Some of the softer concretions I've worked with, I would definitely advise not hitting with a hammer because they typically form multiple cracks when freeze/thawing, and hitting them could cause them, and the fossil, to crumble. Link to comment Share on other sites More sharing options...
pecopteris Posted January 20, 2013 Author Share Posted January 20, 2013 Hi Pecopteris, From reading your post it sounds like you've only frozen and thawed your nodules a single time. Is this correct? If so I think that is the main prroblem. It can take many many freeze thaw cycles to 'pop' open the nodules. The outside of the nodules will often get softer during the process, sometimes flaking off completely. The process is definitely time consuming, you should expect to be freezing and thawing several times a week. Be patient and don't resort to the hammer until you actual start seeing a crack that wraps around the nodule. You can tell if the crack goes all the way through by squeezing the freshly thawed nodule, ones that are almost completely split will squeeze out some water from the crack. Hope this helps. many thanks. "PECO" (Pecopteris) - I specialize in Carboniferous fossils. I have a wide array of plants. In my collection at the moment: Ferns, Calamites, Syringodendron, Aspidaria and Sigillaria. Link to comment Share on other sites More sharing options...
glacialerratic Posted January 21, 2013 Share Posted January 21, 2013 Sounds like the outer layer of the nodule is coming off. When I first started in on Mazon nodules this was a little confusing to me. A lot of the Pit 11 material need 24+ cycles, though there are always exceptions. Some nodules never open. I have a few that have been through 150+ cycles. 48 hrs. on the freeze cycle is plenty. Link to comment Share on other sites More sharing options...
cowsharks Posted January 21, 2013 Share Posted January 21, 2013 Sounds like the outer layer of the nodule is coming off. When I first started in on Mazon nodules this was a little confusing to me. A lot of the Pit 11 material need 24+ cycles, though there are always exceptions. Some nodules never open. I have a few that have been through 150+ cycles. 48 hrs. on the freeze cycle is plenty. Wow. I'm sure glad I don't need to do any of this. Although at first it sounds a little exciting because I'm guessing until the nodule is cracked open, you don't know what (if any) fossil is inside, and whether or not you're about to find something really common or rare? Because of the nature of how/where I collect, the fossils I find don't require any prepping with air abrasion tools, rock hammers and chisels, freezing & thawing cycles, etc. Except for a little light washing when I first bring the teeth home from the beach, I don't need to do much else. Now I can see how some of you folks that collect the Mazon material can easily build up large stores of stuff that need freezing/thawing and prepping - very time consuming and requires more patience than I have. Daryl. Link to comment Share on other sites More sharing options...
glacialerratic Posted January 22, 2013 Share Posted January 22, 2013 Daryl, it really is a lot of work to both find and open the Mazon nodules, but when you DO find a really nice one, that makes it all worthwhile. I still remember the moment opening a really nice annularia stem back in 2004.... Link to comment Share on other sites More sharing options...
Rob Russell Posted January 22, 2013 Share Posted January 22, 2013 Tim, do you recommend freezing them in single layers, or entire bucket fulls at a time? I have around 1200-1400 of them I'd like to start opening. Finding my way through life; one fossil at a time. Link to comment Share on other sites More sharing options...
Stocksdale Posted January 31, 2013 Share Posted January 31, 2013 Wow, 1200-1400. Is this the haul that you posted about in June? Or a more recent trip? At least you don't need use up freezer space this time of year. As part of my January rockhunt planning, I've been scoping out promising spoil piles on google earth. Do you know of any spots in "pit 1" or "pit 6" areas to get Fern Nodules? Somewhere, something incredible is waiting to be known.–Carl Sagan Link to comment Share on other sites More sharing options...
Rob Russell Posted January 31, 2013 Share Posted January 31, 2013 I've only hunted the area twice with esconi on private land. Unfortunately I'm no help when it comes to mazon. Finding my way through life; one fossil at a time. Link to comment Share on other sites More sharing options...
JimB88 Posted February 1, 2013 Share Posted February 1, 2013 alot of folks put em in a bucket with water and leave them outside for the winter. Then check them in spring! Link to comment Share on other sites More sharing options...
glacialerratic Posted February 1, 2013 Share Posted February 1, 2013 Hey Rob, I've done it both ways -- small containers/single layer or a bucket filled. It doesn't appear to really matter, esp. if there is a well preserved fossil inside. However, they still don't open fast enough for me! Link to comment Share on other sites More sharing options...
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