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While visiting family in Arizona and California I was able to figure out where the Marble Mountains trilobite quarry was located. It's not that far off the road system so I figured I'd give it a look see on my drive from central Arizona to Northern California. The location is only about 25 miles out of my way so why not. On my drive north I only had a few hours so this stop was mostly a fact finding trip.

 

The view from the car windshield. The Marble Mountains are the lower hills to the left of center.

6020ccbfbf169_20210111_1608302.thumb.jpg.53c76c07c78bba4d84d1f8efee2f95c5.jpg

 

The quarry area is just to the left of the gap between hills

6020ce80e8039_20210111_1620172.thumb.jpg.367e2259e575127304fa7f254af32baa.jpg

 

Ok, word of notice...... I DO NOT recommend driving a mustang here. I know my car and have driven many places I shouldn't hehehe. I had to stop about 1/4 mile from the site. Don't need a 4x4 but a little ground clearance is a big help. The road is a bit rocky but that is to be expected. It's about 1.5 miles from pavement to parking area.

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The site is just below the gray outcrop just to the left of the mountain gap.

 

I arrived just before sunset and found some locals already at the site (you can just make out their truck in middle photo). They gave me some pointers on what to look for as they were leaving and I set to work. For the first hour I was mostly just wondering around seeing what I could see. There were no obvious recent diggings so I was gonna have to do some digging myself. Went back to the car, grabbed a headlight and went to search in the dark. After about 3 hours I packed up and left to continue my drive north.

 

5 days later I was on my way south back to Arizona. I stopped for a full day of digging this time. Kinda got the basics of the site during this stop. Then back on my way. A week later I was able to slip away for a full 3 day trip just to dig. I was able to spend some quality time on site. It is not a site that you can really hit well in a short time.

 

to be continued......

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Lets talk rock. The main fossil layer is the Latham Shale which is overlaid by the Chambless Limestone. The Latham is lower (early) Cambrian in age. The shale is covered with feet of overburden. It is also very weathered. The first 1-2 feet of bedded shale is pretty much shattered and useless. So, after removing the overburden and lots of shattered shale you finally start to find the layers that are worth trying to split. The rock is a mix of shale with some bedded planes and not. And it tends to fracture at odd angles. Also it has lots of cracks so hard to find big slabs to split (bring lots of glue and clamps)

 

Here is the view of the southern face of the site. The Latham Shale is the loose looking rock under the middle band of block limestone (Chambless Limestone)

6020ded9c36b1_20210112_1335242.thumb.jpg.697f23e6816199a6a8c19150a6d3cf87.jpg

 

Once on site, pick a spot to to dig! There is broken shale everywhere hiding the actual shale beds. Once you commit to a spot then it's time to work. You have between 2-4 feet of loose overburden to move

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Once the overburden is gone (took about an hour to clear an area down 2 feet x 4 feet) then clear off the worst of the shattered shale. Only then can you hope to find pieces big enough to pull off and split that might have a whole cephalon.

 

to be continued (again)..... tomorrow....

Edited by Sjfriend
added age of formation.
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LabRatKing

Great report so far. And as one that once drove a Toyota solara into copper king in Death Valley, I approve of this message.

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2 hours ago, LabRatKing said:

Great report so far. And as one that once drove a Toyota solara into copper king in Death Valley, I approve of this message.

I have similar tales, (Toyota Camry & Dodge Aspen).  I also approve of this message.  Looking forward to seeing some trilobites...

  

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Fossilis Willis
44 minutes ago, jpc said:

I have similar tales, (Toyota Camry & Dodge Aspen).  

  

I used to have a Kia Rio that would go almost anywhere. I took that thing places even my 4x4 SUV won't go. I bet a person could start a whole new topic on this subject (but why do that when we can just high jack this one):P. Thanks for the setup @Sjfriend, can't wait to see how it ends. Lovely scenery by the way.

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So, the fossils to follow were found over the 3 different stops at this locale. Most of course on the last 3 day stop. Due to my limited time on site I actually hunted well past dark each visit. For a reference to the abundance of specimens, when I got back to Arizona and cleaned / trimmed the rock I brought back I filled a large flat rate box with what I was taking home. Took them home on my flights home. 28 pounds of rock in my carry on bag. The TSA security screening folks were quite perplexed but after a couple minutes let it pass (thank goodness!)

 

I mentioned in the previous post that you should bring glue and clamps. In one of my digging hole photos you can see a couple pieces that are already glued and clamped. I glued most of the ones that were damaged when split (most of them). The usual damage is little pieces of shell and the eyes sticking to the split rock. This way I didn't have to worry so much about transporting them. After my first trip I bought a bunch of the little clamps to be ready for my longer visit.

 

Here is a view of my hole. You can see a couple clamped pieces next to the bucket as well as the glue, foil and blue towels used to protect the finds. You can really see how fractured the rock is. Made it a real pain trying to find / pull out any larger pieces. It was amazing how almost every decent larger cephalon was split by a crack or 3!

60216abcb0748_20210120_1320012.thumb.jpg.abbd6162e857350d91013f350e368e1c.jpg

 

99.9% of what you'll find is cephalons and individual thorax pieces. There are a couple things I found online that were used to explain this, 1: the shells were very thin and weakly held together so once the trilobite shed it quickly fell apart. 2: This area had a decent current that tore them apart quickly.

 

So, lets get started. I will state now that I am not 100% on the identification of these trilobites. The size reference gradient is 2mm.

 

One of my favorite "as split" pieces. This one will most likely stay in this condition. A double right side up Olenellus gilberti and Bristolia bristolensis

 

60216e2fec9cb_20210117_1042552.thumb.jpg.df78f1f8027ee3289a4788ce0d14b900.jpg

 

A tiny Olenellus ? and a partial upside down Bristolia bristolensis

60216f2f43b56_20210117_1111472.thumb.jpg.c492ccd80f170cf2afde249f6f9e03e9.jpg

 

There are lots of small ones that are in decent shape, less likely to be fractured lol.

 

to be continued........ most photos only small enough to allow 3-4 at a time...

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Dendrite with buried cephalon. Didn't see the cephalon until after I got it home. Kept the rock because of the dendrites. Someone else posted one like this a while back ( thinking @LabRatKing)

602173ca72884_20210118_1228472.thumb.jpg.b2004586b49b0d8bd5186395e5ea1a04.jpg

 

 

Here is an example of how big the trilobites could get and why I hated how fractured that rock is. Olenellus ? cephalon that would have been around 11cm wide! This photo is when the piece was just exposed before I tried (and failed) to remove it in one piece.

6021745fadd3d_20210121_1024252.thumb.jpg.456eda3b796280f901ca0231357813fd.jpg

 

 

Mesconacis fremonti, This is part of a large slab (have both sides) with multiple cephalons, if I recall there are 9 or 10. My complaint is they are very mixed, positive and negative on each side. So, don't see trying to glue and prep them onto one side being worth the effort. 

602175f12c51e_20210121_1249192.thumb.jpg.f93e593724a98c87a9704d1429955865.jpg

 

 

to be continued.......

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 Thanks for the report.  While looking at all your pictures It looked very familiar.  I think I have two pieces of that rock sittin here on my desk.  I was trying to remember where I got them and only new I was somewhere in california not too far off of old root 66?

 

RB

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Ok, lets take a little break from the main focus of the hunt to show a couple other of finds from the site.

 

Here is a brachiopod, maybe Paterina prospectensis. One of the earliest species.

602178dc875eb_20210120_1321112.thumb.jpg.5aa7ab41f29092fbba9b1f0914bb211d.jpg

 

I did find what I think is a 2nd species but apparently I forgot to get a photo before I boxed them all up.

 

One of the other fossils at the site come from the Chambless Limestone just above the Latham Shale. It is a cyanobactarial fossil, saw both Girvanella and Oncolites listed online as names?? I was worried that it might take a while to find what I was looking for. Ended up taking about an hour....... to find the right size and detailed piece to take home. Kinda hard to miss the fossils in the formation. 1st photo, not what I took home but a lovely piece. 2nd photo is one I kept. I did keep a 2nd to try something on. the limestone is very hard and some of the fossils have great ring structure so I wondered what it would do cut and polished. It cut well, I just have to get it polished up to see the final results.

20210121_140739_2.thumb.jpg.0c4ede8b42d354291504744dbf060f6d.jpg

 

60217b0eadcb5_20210121_0721262.thumb.jpg.88647d17af1f449beb852354bf8ba437.jpg

 

 

Will continue again later.......

 

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14 minutes ago, RJB said:

 Thanks for the report.  While looking at all your pictures It looked very familiar.  I think I have two pieces of that rock sittin here on my desk.  I was trying to remember where I got them and only new I was somewhere in california not too far off of old root 66?

 

RB

That would be the spot I bet. Only about 5-6 miles from 66

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@LabRatKing @jpc and @Fossilis Willis

 

Yes, I have also taken Ford Escorts and a Ford Tempo places that I probably shouldn't. But hey, when your young and brave (ok, really that means young and dumb!) where is the fun in staying within the lines? I do love the looks you get when you pass a big 4x4 in your little car :default_rofl: On the last 1/2 mile to the spot I parked I did hit bottom a couple time but nothing hard.

 

Though on my 2nd stop I had to leave in the dark and missed my turn. Ended up in a sandy wash, oh was that a scare! Kept the gas down and prayed as I tried to just get across and out. I made it! Then got out and spent almost an hour finding a way back across. Had to do a little digging, laid down the floor mats and a couple pieces of wood in the sand but made it. Is it really a fun trip if there isn't some sort of adventure?

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FossilDAWG

A few years ago @Brett Breakin' Rocks sent me some material from that site to use in the teaching collections at my university.  There were quite a few nice Olenellus cephalons and even a few small (~ 1 cm) complete ones as well.  No Bristolia unfortunately.  I didn't know how hard he had to work to get them, and so his generosity is appreciated even more now.

 

Don

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FossilDAWG
40 minutes ago, Sjfriend said:

 ... on my 2nd stop I had to leave in the dark and missed my turn. Ended up in a sandy wash, oh was that a scare! Kept the gas down and prayed as I tried to just get across and out. I made it! Then got out and spent almost an hour finding a way back across. Had to do a little digging, laid down the floor mats and a couple pieces of wood in the sand but made it. Is it really a fun trip if there isn't some sort of adventure?

I did that once in Arizona.  I got a Dodge Caravan minivan seriously stuck in sand in a dry wash.  Plus I had my kids in the car.  Fortunately I was able to wedge enough wood and floor mats under the one rear tire that actually delivered any power to get out before anyone got heat stroke.  Needless to say, no fossil hunting was done that day.

 

Don

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16 minutes ago, FossilDAWG said:

A few years ago @Brett Breakin' Rocks sent me some material from that site to use in the teaching collections at my university.  There were quite a few nice Olenellus cephalons and even a few small (~ 1 cm) complete ones as well.  No Bristolia unfortunately.  I didn't know how hard he had to work to get them, and so his generosity is appreciated even more now.

 

Don

He sent you some nice stuff. In my 4 days I have 1 whole one (not posted in this thread yet) but its buried so have to wait til I can learn to prep it. There are TONS of cephalons there.

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Interesting report with all the details:Smiling:

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On 2/8/2021 at 1:01 PM, Sjfriend said:

One of the other fossils at the site come from the Chambless Limestone just above the Latham Shale. It is a cyanobactarial fossil, saw both Girvanella and Oncolites listed online as names?? I was worried that it might take a while to find what I was looking for. Ended up taking about an hour....... to find the right size and detailed piece to take home. Kinda hard to miss the fossils in the formation. 1st photo, not what I took home but a lovely piece. 2nd photo is one I kept. I did keep a 2nd to try something on. the limestone is very hard and some of the fossils have great ring structure so I wondered what it would do cut and polished. It cut well, I just have to get it polished up to see the final results.

 

 

60217b0eadcb5_20210121_0721262.thumb.jpg.88647d17af1f449beb852354bf8ba437.jpg

 

 

 

Really nice block of Oncolites, Girvanella sp.   Below are pictures of polished slabs from the Chambless Limestone.  Your pieces should look really nice with a highly polished finish.

 

 

6021f974d90b9_4PolishedGIRVANELLAsp.OncolitesalgaeLowerCambrianChamblissLimestoneFormationinSanBernardinoCountyCalifornia4_5x4.5inchesx2inchthick3a.thumb.jpg.94882185c75f0915c17dbc0f6c292d66.jpg

 

6021f976d19f3_5PolishedGIRVANELLAsp.OncolitesalgaeLowerCambrianChamblissLimestoneFormationinSanBernardinoCountyCalifornia5x2.5inchesx1.5inchthick4a.thumb.jpg.c1e29c32ccdb8d60690ad06b496f03e8.jpg

 

6021fa9f797e6_6PolishedGIRVANELLAsp.OncolitesalgaeLowerCambrianChamblissLimestoneFormationinSanBernardinoCountyCalifornia6x3inchesx.875inchthick2a.thumb.JPG.e87681d832e475de32531911ff95ec9b.JPG

 

 

Marco Sr.

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LabRatKing

@Sjfriend excellent site report!

 

I do enjoy dendritic formations. Particularly when in conjunction with fossils!

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LabRatKing
11 hours ago, jpc said:

I have similar tales, (Toyota Camry & Dodge Aspen).  I also approve of this message.  Looking forward to seeing some trilobites...

  

Yeah, I miss my old 65 Baja bug for travel to sites like this one. I should build another.

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Brett Breakin' Rocks
12 hours ago, Sjfriend said:

He sent you some nice stuff. In my 4 days I have 1 whole one (not posted in this thread yet) but its buried so have to wait til I can learn to prep it. There are TONS of cephalons there.

 

12 hours ago, FossilDAWG said:

A few years ago @Brett Breakin' Rocks sent me some material from that site to use in the teaching collections at my university.  There were quite a few nice Olenellus cephalons and even a few small (~ 1 cm) complete ones as well.  No Bristolia unfortunately.  I didn't know how hard he had to work to get them, and so his generosity is appreciated even more now.

 

Don

It started slowly, but once you acclimate yourself to the process you learn that the nicer trilos are sequestered in the new material buried under the over-burden. So there is a nice game you play with brand-new shale that simply does not split nicely. It needs time to be exposed to the elements or it ends up acting like a block of cement. I probably visited that site (or the one near it) over a dozen times over several years living in Los Angeles. 

 

Gods .. I'm just remembering it was a 4 hour trip out ? .. to the site. 

 

Nice finds for your first time out !

 

Cheers,

Brett

 

One day, when my stuff comes out of storage, and we get a new place .. I'll need to scan all of my finds and show them off. One of my finds is sitting in a California school textbook somewhere on the West Coast. 

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Here are few more of my finds:

 

I needed to stretch my back and legs so I took a little look around. Ended up poking around a talus slide from above the Chambless Limestone. I found what I believe to be a Bristolia mohavensis (not sure about this one) from the Cadiz formation.

602203c3cf6b5_20210120_1322022.thumb.jpg.798c4eb523414e12685d606bd4361574.jpg

 

So much that you can find looks like this, piled up bits and pieces. Whole cephalons buried under other parts.

6022053e733f2_20210112_1604332.thumb.jpg.03e3e09ed7c2e518fb5d2d37ea4d5472.jpg

 

Another often overlooked fossil from the site. Hyolith sp? Haven't found anything online yet with an ID for these.

20210208_123557.thumb.jpg.a74bde3e0b9fa4c7283f9a8c9f5666f9.jpg

 

A different brachiopod then the Paterina prospectensis from previous post. Haven't ID'd this one yet.

20210208_123410.thumb.jpg.21d1f164482b5f2be277f23580574193.jpg

 

One more post to go.......

 

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The prize of my trip! Only took 2.5 days to find one that I'm pretty sure is complete. The pygidium is the only part that showed when I split the slab. The fracture curved up over the rest of the trilobite. I know this cause when I tried to trim a corner off the piece, it split into the area of the thorax exposing a little bit. It took a bit of work to glue back together. So, now I have to wait until I can learn how to prep lol (or break down and send off to get done). Doesn't show up great in the photo. No idea what species here. Sure hoping that maybe when I start prepping all the other stuff I brought home that there is another one hiding somewhere.

20210208_123959.thumb.jpg.abac823cbb9c47bbf41ec3e8e884924b.jpg

 

Then there is this. I have no idea what this is. Found a couple during my hunt but this was the best. Don't know if it is anything of interest but I did keep it until I can get an idea.

20210129_095319.thumb.jpg.fc1f6803b73dd0c415ae4921308bdabd.jpg

 

So, after 4 full days of digging I have quite a few pieces to prep to see if I can get a few nice cephalons from as many species as I can. I know there are a number of different ones in my box. It may be quite a while to get to that point as I'm just getting starting collecting the right tools. And as there are a fair number of species from the formation it might take a while to figure out which ones I have.

 

I'll end with a photo of my travel companion, since my wife couldn't come she sent a babysitter, her bear Princess Rainbow traveled with me for all my trips to the site.

60220f57572ac_20210112_0735022.thumb.jpg.72ea39ef6c3bb3b8f0be2e46cf2b4535.jpg

 

 

 

 

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FossilNerd

Nice trip reports and finds. Thanks for sharing! :) 

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21 hours ago, Sjfriend said:

In my 4 days I have 1 whole one (not posted in this thread yet) but its buried so have to wait til I can learn to prep it. There are TONS of cephalons there.

Enjoying your adventure in warmer temperatures with multiple fossils to observe and learn about. I just finished reading a well reviewed book on trilobites and concurrently  another about plate tectonics as it relates to the formation of Alaska’s various terrains. I would be happy to loan you the air scribe I recently acquired to see how it does for your new finds. I’m fully vaccinated now and ready to be more sociable with still keeping the current guidelines in place. I hope we can get together this summer and have several spots in mind with trilobites on the menu for two jaunts. 
Bob

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6 hours ago, AK hiker said:

Enjoying your adventure in warmer temperatures with multiple fossils to observe and learn about. I just finished reading a well reviewed book on trilobites and concurrently  another about plate tectonics as it relates to the formation of Alaska’s various terrains. I would be happy to loan you the air scribe I recently acquired to see how it does for your new finds. I’m fully vaccinated now and ready to be more sociable with still keeping the current guidelines in place. I hope we can get together this summer and have several spots in mind with trilobites on the menu for two jaunts. 
Bob

Would love to meet up! Not vaccinated yet (too young at 55 lol). I am back home now too. Just took 2nd post travel test, 1st was clean lol.

 

Wouldn't mind trying the scribe BUT have no indoor shop to use yet and still a little chilly outside to do much detail work. Maybe come spring?

 

When I looked up possible trilobite sites here they were a little too off-road for my hiking abilities :heartylaugh:

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