Pliocene? Southern California fossils

[Wrangellian]

The other day I acquired a few fossils from fellow members of the rockhound club who spend their Winters (except this past winter) down in Arizona and collect there and in neighboring states.

They gave me the location via the Gem Trails book they used to find it, but of course that doesn't provide any info on the formation nor any specific IDs for what you find there. I'm having trouble (as usual) finding this information, so I wonder if anyone here has this info handy. I found a geo map of Calif and it appears to be Pliocene in that area, but it doesn't give any formation names. The area is in the Coyote Mountains, SW of the Salton Sea, north of Ocotillo. Looks like you drive north out of Ocotillo to get to the site.

Anyone know the formation name or recognize the taxa I have here? Just two items, a basic bivalve (3 views) and a sand dollar-type echinoid (2 views).

 

Edited April 28, 2021 by Wrangellian

[DPS Ammonite]

The Imperial Formation has marine fossils.

 

https://ngmdb.usgs.gov/Geolex/UnitRefs/ImperialRefs_5629.html

[Thecosmilia Trichitoma]

I know that Fossil Canyon is nearby. @LabRatKing has collected in the area.

[Wrangellian]

That's right, I should have mentioned the place is called Fossil Canyon, I believe that's the site they collected. Thanks both. I'll see what more info I can dig up  with these leads...

[Wrangellian]

After a couple hours searching I have only gathered that the sand dollar may be Encope tenuis, and the Imperial Fm is now the Imperial Group, so I still don't know for sure what formation these fossils are from, but it's a little more than I had before.

[LabRatKing]

10 hours ago, Thecosmilia Trichitoma said:

I know that Fossil Canyon is nearby. @LabRatKing has collected in the area.

Over two decades ago, yes, but I did take a few trips to the area. It was the quietest place I could get to within driving distance (in a 1970 VW bug) from Naval Station 32nd Street.

 

 

It is my understanding now it is part of the magnificent Anza-Borrego State park, so no collecting anymore. The Canyon I most often frequented was strictly bivalves- specifically scallops- and known as "Shell Canyon". Fossil Canyon was a different site to my knowledge, (Ocotillo if memory serves) but still in the sandstone. Admittedly, in those days I never worried about formations and members and such.

 

Ironically, my specimens from those days are at the bottom of the Pacific Ocean off the coast of Caleta Cinfuncho, Chile.

12 hours ago, Wrangellian said:

The other day I acquired a few fossils from fellow members of the rockhound club who spend their Winters (except this past winter) down in Arizona and collect there and in neighboring states.

They gave me the location via the Gem Trails book they used to find it, but of course that doesn't provide any info on the formation nor any specific IDs for what you find there. I'm having trouble (as usual) finding this information, so I wonder if anyone here has this info handy. I found a geo map of Calif and it appears to be Pliocene in that area, but it doesn't give any formation names. The area is in the Coyote Mountains, SW of the Salton Sea, north of Ocotillo. Looks like you drive north out of Ocotillo to get to the site.

Anyone know the formation name or recognize the taxa I have here? Just two items, a basic bivalve (3 views) and a sand dollar-type echinoid (2 views).

 

 This publication might help (my memories of the area are somewhat faded after all these years!)

 

https://www.sdnhm.org/download_file/view/5186/660/

 

And this one provides some heavier details on the stratigraphy:

 

https://www.researchgate.net/publication/260274630_Stratigraphic_record_of_Pleistocene_faulting_and_basin_evolution_in_the_Borrego_Badlands_San_Jacinto_fault_zone_Southern_California

Edited April 28, 2021 by LabRatKing

[Wrangellian]

Thanks, LRK. That 2nd link seemed to focus more on the younger formations, post-Imperial Gp, but the first pdf seemed to cover it well enough that I think I can call my fossils Latrania Fm, which apparently is Uppermost Miocene-?

Looks like you're right, Fossil Canyon is just north of Ocotillo, outside of the park. Kind of halfway between the town and the park, so no worries about collecting being barred.

Now to confirm the age of the Latrania, uppermost Miocene (Messinian) or Lower Plio (Zanclean) - either way I'll be able to plug another hole in my 'Collecting the Stages' project.

 

How did your specimens end up on the bottom of the ocean off Chile? That sounds like a story!

[LabRatKing]

4 minutes ago, Wrangellian said:

Thanks, LRK. That 2nd link seemed to focus more on the younger formations, post-Imperial Gp, but the first pdf seemed to cover it well enough that I think I can call my fossils Latrania Fm, which apparently is Uppermost Miocene-?

Looks like you're right, Fossil Canyon is just north of Ocotillo, outside of the park. Kind of halfway between the town and the park, so no worries about collecting being barred.

Now to confirm the age of the Latrania, uppermost Miocene (Messinian) or Lower Plio (Zanclean) - either way I'll be able to plug another hole in my 'Collecting the Stages' project.

 

How did your specimens end up on the bottom of the ocean off Chile? That sounds like a story!

I liv d on the ship at the time. We managed to hit the continent at around 12 knots. Google “LST 1194 Chile” for all the “details” officially released.

 

The actual  story is better around a campfire with beverages....

 

one of these days I’ll have to get back out to the site and replace them. The scallops were hand sized and perfect!

[Wrangellian]

Oh, that kind of story, gotcha.

 

Yes, if they're still collectable, why not? If I could I'd add to my samples a nice scallop or whatever else, too. The people I got these from also had some of the snails and such that are just interior moulds, rather grotty so I didn't bother with any of those, as my drawer space is limited and I need to be pickier than I have been in the past.

 

I do have one oyster that I showed on TFF ages ago as I acquired it with no info whatsoever, and someone suggested it was from the Pliocene of SoCal and I wonder if it's from this place, now that I know more about this place. I can't find my photos of it so I'll redo them and post here.

Edited April 29, 2021 by Wrangellian

[Wrangellian]

Here it is.... The suggestion was Ostrea or Crassostrea sp, probably from Carrizo Creek Formation, Ocotillo, CA. Does it look familiar? 

I think if the person who stuck the label on there had known better than to use a fade-prone felt pen on masking tape, I might not be asking about this one...

The lady I got the above fossils from also had an oyster, similar but not identical to this one (it lacked those finger-like radiating ribs and was larger and complete with both valves). The person who gave it to her said they couldn't remember where they had picked up but it was somewhere in the SW states. I told her I had this one and suspected it was from the same area.

[Crusty_Crab]

That reminds me of the oysters found at the Yuha Buttes, Pycnodonte heermanni (Conrad, 1855). There's an article about the area and the formation:

https://delversgemclub.files.wordpress.com/2015/12/delvings_2016-12.pdf

 

You may also want to check Moore's paper to verify the species: https://pubs.usgs.gov/pp/1228c/report.pdf

 

[Wrangellian]

Aha! I don't know why I couldn't find the Fossil Treasures pdf #3... I found #2 but #3 was the Invert one. Thanks!

I'm now confident the sand dollar is Encope tenuis. The bivalve might be Periglypta multicostata or Ventricolaria isocardia.

They oyster must be Pycnodonte heermanni. Haven't narrowed down the possible location of origin yet as it occurs in both the Deguynos and Latrania formations. Could be Yuha Buttes... Where are they most commonly found (in areas that are legal to collect)?

Edited April 30, 2021 by Wrangellian

[Crusty_Crab]

14 hours ago, Wrangellian said:

Aha! I don't know why I couldn't find the Fossil Treasures pdf #3... I found #2 but #3 was the Invert one. Thanks!

I'm now confident the sand dollar is Encope tenuis. The bivalve might be Periglypta multicostata or Ventricolaria isocardia.

They oyster must be Pycnodonte heermanni. Haven't narrowed down the possible location of origin yet as it occurs in both the Deguynos and Latrania formations. Could be Yuha Buttes... Where are they most commonly found (in areas that are legal to collect)?

 

My understanding is that the Yuha Buttes is the most common place to collect the oysters. It is BLM land and the ground is covered with them. 

[LabRatKing]

So bear with my rusty memories, but, yeah, oyster heaven round there!

 

 I’m planning a September trip out that way since I got involuntarily roped into a burial at sea for an old buddy.

 

perhaps we should test the Science Mobile and assess?

[DPS Ammonite]

51 minutes ago, LabRatKing said:

Science Mobile

Do you have a picture and description of the Science Mobile?

[Wrangellian]

10 hours ago, Crusty_Crab said:

 

My understanding is that the Yuha Buttes is the most common place to collect the oysters. It is BLM land and the ground is covered with them. 

OK.  I've already forgotten what I read in the papers, but what formation is exposed at Yuha Buttes, Deguynos?

[Crusty_Crab]

24 minutes ago, Wrangellian said:

OK.  I've already forgotten what I read in the papers, but what formation is exposed at Yuha Buttes, Deguynos?

 

Come to think of it, I don't ever recall seeing that location geologically mapped unlike the area north of I-8 which is extensively mapped. If I had to wager, I'd guess the Yuha Member of the Deguynos, which is indicative of a "delta front with oyster beds."  https://darkwing.uoregon.edu/~rdorsey/Downloads/DorseyChaperNov05.pdf

[Wrangellian]

Thanks.

Yeah, that's my trouble: finding good maps that correspond to good strat charts!

[siteseer]

On 4/29/2021 at 7:40 PM, Wrangellian said:

Aha! I don't know why I couldn't find the Fossil Treasures pdf #3... I found #2 but #3 was the Invert one. Thanks!

I'm now confident the sand dollar is Encope tenuis. The bivalve might be Periglypta multicostata or Ventricolaria isocardia.

They oyster must be Pycnodonte heermanni. Haven't narrowed down the possible location of origin yet as it occurs in both the Deguynos and Latrania formations. Could be Yuha Buttes... Where are they most commonly found (in areas that are legal to collect)?

 

Wrangellian,

 

I don't know if you're referring to it or not but there is a nice book, "Fossil Treasures of the Anza-Borrego Desert edited by George T. Jefferson and Lowell Lindsay (Sunbelt Publications in cooperation with California State Parks and Anza Borrego Foundation & Institute, 2006).  It goes over the changing landscape that was seascape seven million years ago with lots of photos of fossils and great illustrations.

 

Jess

[LabRatKing]

18 hours ago, DPS Ammonite said:

Do you have a picture and description of the Science Mobile?

Soon! I’m rushing to finish it be Memorial Day.

I found a Jeep Liberty for 500$- only thing wrong with it was the front CV failed. 150$ in parts and bit of wrenching and Was good to go! Pulled rear seats and installed a flat floor over low profile water and wastes tanks.

waiting on Toyos to be delivered and will start the cabinets this week. Don’t know if I’ll have the linex coat on this month, but will before July 

[Wrangellian]

6 hours ago, siteseer said:

Wrangellian,

I don't know if you're referring to it or not but there is a nice book, "Fossil Treasures of the Anza-Borrego Desert edited by George T. Jefferson and Lowell Lindsay (Sunbelt Publications in cooperation with California State Parks and Anza Borrego Foundation & Institute, 2006).  It goes over the changing landscape that was seascape seven million years ago with lots of photos of fossils and great illustrations.

Jess

Thanks, I am seeing what are apparently chapters from this book in pdf format online, which contain a lot of this info. I hope to avoid buying any books just to ID a few fossils - it could get expensive. That's why I come here first!

[Boesse]

I actually wonder if the big bivalve is a geoduck, Panopea sp.

[Wrangellian]

1 hour ago, Boesse said:

I actually wonder if the big bivalve is a geoduck, Panopea sp.

Thanks. I wondered about that... the gape part is kind of ambiguous until maybe I prep it out, but I'm scared to.