Sjfriend Posted January 8, 2022 Share Posted January 8, 2022 In October of 2021 I made a 4 day trip to the Marble Mountains of Southern California to look for trilobites. The order of note is Redlichiida. The biggest percentage is Olenellus followed by Bristolia then Mesonacis. The vast majority of finds are just cephalons followed by thorax pieces. Last year I hunted here about 8 days. I probably found over 400 cephalons (could be a way higher) but only 2 completes with 3 maybe's as there are buried. With all that I've only found 1 pygidium on its own. There are a few other fossils to be found at the site. A couple brachiopods, a hyolith, and a few other invertebrates along with trace fossils are also among the possible finds When I'm visiting family in Arizona this is my new go to spot..... mostly because it is the closest with trilobites (which of course are the best fossils out there ) It takes me about 6 hours to drive there so it makes sense to spend some time on the site. I usually end up hunting well into the night to make my time count. There are a few sights to see along the way as well, the Amboy Volcano National Monument and the ghost town of Amboy. Both are along the Historic Route 66. Scale shown in the specimen photos is: little marks are 2mm and the numbers are cm Amboy sunrise The site is near the old town of Cadiz. Here is a sign near the turnoff for the site. Once onsite you have to pick a spot and start digging. There is about 2ft of very broken and fragmented shale overburden to deal with (between the red lines) Bring a mask! This stuff kicks up a TON of dust and it's not really that healthy to breath in. This spot has been know for decades and as such the overburden from the upper digs is burying the lower sections. Would be nice if we were allowed to bring in some bigger gear to remove a lot of it to make accessing the lower areas practical. But, being on BLM land, only regular hand tools allowed. After picking my spot to play, and digging the overburden out of the way, it was time to break rock. My spot for the next 4 days So, as I stated, the vast majority of finds are lone cephalons. They range in size from a couple mm to over 10cm! Unfortunately the large ones are so hard to find intact. With the rock being so fragile / fragmented sometimes they are in dozens of tiny pieces making it about impossible to fix. So, you keep digging and splitting to find more. Mesonacis fremonti cephalon And, sometimes the preservation is weird or just awful And then you find a nice large cephalon that isn't broken (and stays that way when you try to remove it) Olenellus nevadensis cephalon (I think) One of the best large ones I've found yet. There are quite a few smaller ones to be found in decent shape. Sometimes they are really little if you keep you eyes open Olenellus clarki cephalon (I think. The smaller ones are harder to tell for me as I have not found a good reference) Sometimes you get lucky and find a multi plate with nice examples I believe this is a Olenellus double (not quite sure of species yet but it appears to be 2 different species. I really like this multi. 4 individuals all right side up. It appears to be 3 Olenellus clarki and one I haven't ID'd yet (still wrapped from travel) Double Olenellus clarki with one ventral and one dorsal (positive and negative) My only pygidium after looking at thousands of trilo - bits It appears that when they molt that the parts are barely held together. As such they tend to fall apart quickly. That is part of the theory as to why so few completes are found here. As such I did find this large thorax section. I'm hopeful that the rest is buried but it doesn't look promising (positive and negative) But after 8 total days of digging I only have a few complete. Most are partial buried. BUT, I finally found one that popped out just great! It's missing a tiny bit of cephalon but I can live with that. A little prep would uncover the hidden pleural. And maybe clean up the extra cephalon. Olenellus clarki Since this is my closest accessible spot I'll keep going back. There are a number of other species I can still try and locate complete ones, or at least nice cephalons of the different species. My dream is a large complete one. And now that you have (or I have in this case) collected your finds a word of note: since this is US government land you are allowed to collect BUT no selling or trading of specimens. You may give them away but no compensation. Speaking of this, in the future I will have some to give out once I figure what I've got and pull out my keepers. There is more to come but my computer and the internet aren't talking well at the moment so I can't download more photos. To Be continued 8 17 Link to comment Share on other sites More sharing options...
ChristineR Posted January 8, 2022 Share Posted January 8, 2022 Thanks for posting this great report. I now know what to look forward to. Eight days of digging hurts just to think about. That nearly complete Olenellus clarki is beautiful. Congrats! Link to comment Share on other sites More sharing options...
RuMert Posted January 8, 2022 Share Posted January 8, 2022 Great report 1 hour ago, Sjfriend said: I probably found over 400 cephalons (could be a way higher) but only 2 completes That's what I hate about fossil hunting - too many rejects in many sites BTW, the preservation might be not always good but it's certainly very stylish My sites & reports Link to comment Share on other sites More sharing options...
Huntonia Posted January 8, 2022 Share Posted January 8, 2022 Oh man! What an awesome trip, thanks for sharing! Looks like some tough digging but the effort sure paid off for you, that Mesonacis cephalon and the O. clarki are real gems!! Are you still in the process of setting up a prep lab? I think I remember you mentioning that a while ago. Link to comment Share on other sites More sharing options...
pachy-pleuro-whatnot-odon Posted January 8, 2022 Share Posted January 8, 2022 Not a trilobite-guy myself, but this read an awesome report. And while you may not have a lot of complete specimens, your best pieces are absolute stunners! Certainly worth the effort, I'd say! But at six hours driving I can't imagine you going up and down to your family on a daily basis, yet the surroundings of the quarry seem quite desolate and abandoned too. Where do you stay? Do you camp out? 'There's nothing like millions of years of really frustrating trial and error to give a species moral fibre and, in some cases, backbone' -- Terry Pratchett Link to comment Share on other sites More sharing options...
Fossildude19 Posted January 8, 2022 Share Posted January 8, 2022 Thanks for the great report! Glad you were rewarded with a few complete specimens for your hard work! Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
FossilNerd Posted January 8, 2022 Share Posted January 8, 2022 Very nice report! I’d be happy with just a couple of cephalons, but that Olenellus clarki is a real beauty. Congrats on the great finds. The good thing about science is that it's true whether or not you believe in it. -Neil deGrasse Tyson Everyone you will ever meet knows something you don't. -Bill Nye (The Science Guy) Link to comment Share on other sites More sharing options...
RJB Posted January 8, 2022 Share Posted January 8, 2022 You made this a fun read with my morning coffee. RB Link to comment Share on other sites More sharing options...
RCFossils Posted January 8, 2022 Share Posted January 8, 2022 Wonderful report! That is a site that is definitely on my bucket list to visit. Link to comment Share on other sites More sharing options...
flipper559 Posted January 8, 2022 Share Posted January 8, 2022 Very nice report !! Congratulations on the cool finds !! Hard work pays off !! Rock On !! Phil Link to comment Share on other sites More sharing options...
deutscheben Posted January 8, 2022 Share Posted January 8, 2022 Wow, what a great report! Kudos for putting in the work to get those finds too, that is an impressive level of dedication. Link to comment Share on other sites More sharing options...
Sjfriend Posted January 8, 2022 Author Share Posted January 8, 2022 9 hours ago, Huntonia said: Oh man! What an awesome trip, thanks for sharing! Looks like some tough digging but the effort sure paid off for you, that Mesonacis cephalon and the O. clarki are real gems!! Are you still in the process of setting up a prep lab? I think I remember you mentioning that a while ago. Thanks. And yes. Started getting the extra pieces for the air system. Already have a big compressor, older CP scribe (that I'm gonna send to Paleo Tools to refurbish) and a abrasion tool but what I really need to do to get it going is build a little work shed. Have a big one but it's already full of other tools. Trying to figure where to build it??? 1 Link to comment Share on other sites More sharing options...
Sjfriend Posted January 8, 2022 Author Share Posted January 8, 2022 8 hours ago, pachy-pleuro-whatnot-odon said: Not a trilobite-guy myself, but this read an awesome report. And while you may not have a lot of complete specimens, your best pieces are absolute stunners! Certainly worth the effort, I'd say! But at six hours driving I can't imagine you going up and down to your family on a daily basis, yet the surroundings of the quarry seem quite desolate and abandoned too. Where do you stay? Do you camp out? Yeah, a bit of a drive. Being the nut case that I am I camp out in my car. It is not an old quarry. It is just a long worked over shale / limestone hillside. The site has been worked over for over 70 years. There is a tiny farming area nearby but it is pretty "out there" Closest real town is about 50 miles 1 1 Link to comment Share on other sites More sharing options...
Sjfriend Posted January 8, 2022 Author Share Posted January 8, 2022 Here are a few more of the finds and sights. As @pachy-pleuro-whatnot-odon pointed out, it is a pretty isolated area. Which like as it helps keep the site a little less worked. I have meet a few locals at the site the first time I went there. They live a few miles away. They were nice and even said if I got stuck they'd come help. So glad I haven't had to hike out to ask Bristolia mohavensis cephalon (positive and negative) Bristolia mahovensis cephalon (covered with calcite) This shows a common issue here. Some pieces are just buried in little calcite crystals. Makes for extra work if you need to glue top/bottom back together for prepping. Another shot showing just how much repair a cephalon can take. The matrix is just so fractured. And the fracture planes are not always flat or straight. Mesonacis fremonti cephalon during repair. Already 4 pieces glued back on and 3 to go. Speaking of lots of repairs! This one will end up in another post soon. This photo is of a large slab still in place. It took me about 10 hours to uncover and remove. This is the only one I've found like this. Most specimens have been singles or a couple cephalons then a big gap before more are found. This slab showed a few that disappeared into the face so I had to move a lot of rock to get back to the level to continue following the slab. I had to move 2 feet of overburden then work my way down through about 2 feet of matrix. When I finished I had this piece uncovered as much as I could. I wonder how much I ended up leaving in the cliff but I was out of days. So, I grabbed what I could. Now the reason I worked so hard: on this slab there is over 25 cephalons and 1 buried that appears to be a little complete one. The bad news: you can see a bunch of fractures running through the slab.... and that isn't all of them. Even with using a couple tubes of super glue it came out in about 20 pieces So, I had a bunch of work ahead of me. A couple of other invertebrates that can be found. First one is more common. Second one not so much. I have found dozens of brachiopods though there is still one I haven't found. Paterina prospectensis (brachiopod) This one I think is an example of Bergaueria radiata but I'm not positive. It sure looks like it to me and it is the only piece like this I've seen in all the rock I've broken there And after a couple days digging and breaking rock, I left a nice pile for the next digger to go through. The pile behind the 2.5 gallon bucket is almost completely cephalons of varying degrees of preservation and completeness. There are quite a few complete ones but of species I already had a few of. The few on the blue towel are waiting to be wrapped and hauled out. On my last day the wind really picked up and filled the valley with dust. Not like I wasn't already covered in dirt Taken from the dig site. Can just see my car near where the trail disappears into the dust cloud. To close out, one of the joys of camping out is watching the sun set over an area with no lights (except for the non-stop trains going down the valley) Taken from the dig site Until next time 2 8 Link to comment Share on other sites More sharing options...
Huntonia Posted January 10, 2022 Share Posted January 10, 2022 On 1/8/2022 at 9:21 AM, Sjfriend said: Thanks. And yes. Started getting the extra pieces for the air system. Already have a big compressor, older CP scribe (that I'm gonna send to Paleo Tools to refurbish) and a abrasion tool but what I really need to do to get it going is build a little work shed. Have a big one but it's already full of other tools. Trying to figure where to build it??? Sounds like your almost there! It can be tough to find the space for it! I'd recommend you get a smaller scribe as well as the Chicago Pneumatics, if the preservation on these guys is similar to the Pioche shale you're likely to run into pieces with subpar separation that won't abrade well Link to comment Share on other sites More sharing options...
Sjfriend Posted January 10, 2022 Author Share Posted January 10, 2022 (edited) 11 hours ago, Huntonia said: Sounds like your almost there! It can be tough to find the space for it! I'd recommend you get a smaller scribe as well as the Chicago Pneumatics, if the preservation on these guys is similar to the Pioche shale you're likely to run into pieces with subpar separation that won't abrade well I'm looking at the Fossil Shack scribe (smaller and cost). And it does look like the separation isn't good when they are partially buried. Forgot to mention in my "needed" equipment list, a microscope as well. Have jeweler glasses but want the scope before I get too into this prep thingy Edited January 10, 2022 by Sjfriend Link to comment Share on other sites More sharing options...
Huntonia Posted January 12, 2022 Share Posted January 12, 2022 On 1/10/2022 at 9:44 AM, Sjfriend said: I'm looking at the Fossil Shack scribe (smaller and cost). And it does look like the separation isn't good when they are partially buried. Forgot to mention in my "needed" equipment list, a microscope as well. Have jeweler glasses but want the scope before I get too into this prep thingy I haven't used the Fossil Shack scribe but I hear good things, should serve you well! The microscope is definitely a must have! 1 Link to comment Share on other sites More sharing options...
Reebs Posted January 12, 2022 Share Posted January 12, 2022 Wow, nice finds. Cool trip. Thanks for sharing! Link to comment Share on other sites More sharing options...
Paleorunner Posted January 12, 2022 Share Posted January 12, 2022 Thank you for sharing this wonderful report. Not bad, but I wish you better luck next time. (more complete trilos). Link to comment Share on other sites More sharing options...
Sjfriend Posted January 12, 2022 Author Share Posted January 12, 2022 Thank you all! It was a fun (though dusty) trip. @Paleorunner I too wish for more completes but I will say, knowing how uncommon they are sure made for a lot of excitement when I found it! I've seen papers saying they range from less then 1% to about 2% of finds. My experience so far leans towards the less then side. Oh well, more reason to keep digging! There are more then a dozen species from there so I have a few more to go to complete the set 1 Link to comment Share on other sites More sharing options...
Paleorunner Posted January 12, 2022 Share Posted January 12, 2022 It is a low percentage, but when you find them it has to be very rewarding. If you keep insisting, sure you will have good rewards. Good luck.......... Link to comment Share on other sites More sharing options...
Sjfriend Posted January 12, 2022 Author Share Posted January 12, 2022 1 minute ago, Paleorunner said: It is a low percentage, but when you find them it has to be very rewarding. If you keep insisting, sure you will have good rewards. Good luck.......... Thanks. Oh the thrill of the hunt 1 Link to comment Share on other sites More sharing options...
Oxytropidoceras Posted January 14, 2022 Share Posted January 14, 2022 On 1/8/2022 at 12:30 AM, Sjfriend said: There is about 2ft of very broken and fragmented shale overburden to deal with (between the red lines) Bring a mask! This stuff kicks up a TON of dust and it's not really that healthy to breath in. This spot has been know for decades and as such the overburden from the upper digs is burying the lower sections. Would be nice if we were allowed to bring in some bigger gear to remove a lot of it to make accessing the lower areas practical. But, being on BLM land, only regular hand tools allowed. Maybe a regional gem and mineral group could send a letter to the appropriate BLM manager pointing out the need to remove the waste rock as part of managing the locality / resource. To mitigate the need for funding, part of the request would be an offer by the gem and mineral society / societies to provide a group of volunteers that would provide the labor to it under the supervision of BLM personal. It might be naive of me. But they might allow it if it is done as a planned, special resource management exercise that is under the supervision of the BLM. Yours, Paul H. Link to comment Share on other sites More sharing options...
Sjfriend Posted January 14, 2022 Author Share Posted January 14, 2022 2 hours ago, Oxytropidoceras said: Maybe a regional gem and mineral group could send a letter to the appropriate BLM manager pointing out the need to remove the waste rock as part of managing the locality / resource. To mitigate the need for funding, part of the request would be an offer by the gem and mineral society / societies to provide a group of volunteers that would provide the labor to it under the supervision of BLM personal. It might be naive of me. But they might allow it if it is done as a planned, special resource management exercise that is under the supervision of the BLM. Yours, Paul H. It would be great! Though I highly doubt it would be allowed it never hurts to ask (so they say ) I would even travel the 4000 miles to help! Of course I'd have to do some looking while there..... and maybe visit my family Link to comment Share on other sites More sharing options...
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