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Roadrunner

Finds Today That I Can't Id

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Roadrunner

....and then this limestone;

DSCN0811_zpsbd4869a2.jpg

Closer in on part of it (those are centimeters at the top).

DSCN0812_zps794291e1.jpg

It looks like the sponge "porifera" on the right according to the web page below;

http://www.nhm.ac.uk/research-curation/collections/our-collections/fossil-invertebrate-collections/porifera/index.html

Edited by Roadrunner

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Roadrunner

I found a paper on the geology of the area, which somewhat explains why I have so much trouble identifying samples;

Of course, I don't expect anyone to read all of it - but I suppose it might help me with some future identifications.

GEOLOGY

About 40-50 percent of the rocks exposed in the Sandia Mountains are of Precambrian age and include the Sandia Granite (1,445±40 m.y.), which intrudes older biotite schist and gneiss of Kelley and Northrop (1975) and the Cibola Gneiss, and a still older northeast-striking greenstone belt along Tijeras Canyon. The Tijeras Greenstone of Kelley and Northrop (1975), of probable Proterozoic X (Early Proterozoic) age, consists of predominantly dark-greenish-black, blastoporphyritic metabasalt flows, and minor thin lenses of metarhyolite. The absence of pillow structures in the greenstone suggests predominantly subaerial extrusion. The slightly younger Cibola Gneiss is a granitic paragneiss containing intercalated and isoclinally folded quartzite beds. The gneiss and schist of Rincon are highly foliated, biotitic-sillimanitic, metapelitic rocks that have been intricately intruded by the post-orogenic Sandia Granite. Numerous pegmatite and aplite dike swarms that are largely fracture controlled intrude the metapelitic rocks.A relatively thick (2,500 ft) section of Mississippian, Pennsylvanian, and Permian strata rests unconformably on the Precambrian rocks and forms an extensive east-dipping dip slope on the tilted fault block. The Mississippian strata are thin (50 ft), discontinuous, erosional remnants of cherty limestone. The Pennsylvanian section is about 800 ft thick and is represented by carbonaceous shale and sandstone of the Sandia Formation and an overlying thick (650 ft) sequence of shallow marine limestone beds of the Madera Group (Myers, 1973). No attempt was made in this study to differentiate the various units in this group. A complex Permian and Triassic red-bed section of sandstone, siltstone, mudstone, and thin limestone beds crops out farther down the dip slope. From oldest to youngest these are the Permian Abo, Yeso, and San Andres Formations, and the Triassic Santa Rosa Sandstone and Chinle Formation.The remaining Mesozoic strata are folded into synclinal basins, such as the Tijeras and Hagan synclines and also fill ramplike depressions near Placitas (Kelley and Northrop, 1975, p. 83).

The Jurassic and Cretaceous sedimentary rocks include the Jurassic Todilto, Entrada, and Morrison Formations

and the Upper Cretaceous Mancos and Mesaverde Formations. Black carbonaceous shale and thin coal beds are commonly interbedded with thick sandstone beds in the Mesaverde Formation.Middle Tertiary(?) lamprophyric dikes cut the Sandia Granite along the steep west-facing slope of the Sandia Mountains, and a basaltic dike cuts the Mesaverde Formation about 1 mi northwest of Placitas. The Galisteo Formation of early Tertiary age crops out as an incomplete section north of the wilderness boundary west of Placitas.The dominant structural element is the east- tilted Sandia fault block, which is controlled on the west by the Sandia and Rincon-Ranchos range-front faults. These faults have as much as 20,000-28,000 ft of throw. The eastward tilt of 15°-20°, formed in conjunction with displacement along these faults, steepens where the Paleozoic section underlies the folded Mesozoic sedimentary rocks of Tijeras and Hagan basin synclines.The plunging northern terminus of the fault block is near Placitas, but, to the south, the Sandia fault block is contiguous with the Manzanita and Manzano fault blocks. Numerous north-trending faults along the dip slope are considered coeval with the Pliocene and Miocene Sandia-Rincon- Ranchos faults and commonly displace older faults of post-Permian (principally Laramide) age. Most of the north-trending dip-slope faults are downthrown to the east, but the large Ellis fault is an exception and locally reverses the regional east dip so that near Capulin Peak the strata dip gently to the west. Probably the most important effect of these faults has been to bring Precambrian rocks to the surface along the back-slope between Tejano and Tecolote Canyons.The Placitas-San Francisco, Tijeras and Gutierrez faults strike northeast to east-northeast along the north and south boundaries of the Sandia Mountains. These faults, principally of Laramide age, locally displace the Upper Cretaceous Mesaverde Formation and are commonly branching or splayed fault systems having combined throws as much as 1,000-3,000 ft. The Tijeras and Gutierrez faults bound the Monte Largo horst and the Tijeras graben and syncline; a scissorslike displacement with some strike-slip displacement is characteristic of these faults. Most of the northeast and east-northeast faults have had numerous periods of movement. For example, the Tijeras fault was probably active in the Precambrian with some left-slip displacement (Connolly, 1982), and again during late Paleozoic, Laramide, middle Tertiary,and Holocene times. The Placitas-San Francisco fault system probably had a similar history with the principal displacement taking place during
Laramide time.
Edited by Roadrunner

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Auspex

Yeep! Pretty messy...

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Roadrunner

Yup - I guess messy can also be interpreted as "interesting." :wacko:

Thanks for reading it.

Edited by Roadrunner

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Wrangellian

I think your sponge in the last photo is a bryozoan.

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Missourian

If this is a coral, does anybody know what kind? I've not seen one like it before;

For sizing;

Hopefully, a better shot;

If Pennsylvanian, it most likely is Caninia torquia.

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Roadrunner

I think your sponge in the last photo is a bryozoan.

You've got me researching the definitions of bryozoans and sponges again. I'll need to read further to fully understand. Thank you! :)

Edited by Roadrunner

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Roadrunner

If Pennsylvanian, it most likely is Caninia torquia.

That caught me by surprise. I thought the Caninia torqua were more horn-shaped corals with spiral-shaped septa.

Aside from remotely looking like a little tennis shoe footprint, ;) I'm still not being successful in finding similar image samples.

I'll keep looking. Thank you for your input!

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Missourian

That caught me by surprise. I thought the Caninia torqua were more horn-shaped corals with spiral-shaped septa.

Aside from remotely looking like a little tennis shoe footprint, ;) I'm still not being successful in finding similar image samples.

I'll keep looking. Thank you for your input!

I think it's the only Penn. type that gets that large (but I could be mistaken). The form of these corals can range from horn to cylindrical. And that's before weathering of the rock surface leaves all kinds of fanciful shapes. :)

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Roadrunner

I think it's the only Penn. type that gets that large (but I could be mistaken). The form of these corals can range from horn to cylindrical. And that's before weathering of the rock surface leaves all kinds of fanciful shapes. :)

OK - thanks!

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Roadrunner

I've several pieces here - which I think are petrified wood. They were all found within a mile of each other, and yet all look very different.

Can anyone point me in the direction of a resource where I might try to identify which wood(s) made these, if they are in fact petrified wood?

First, the 2 largest pieces together (sorry for the picture quality - it is extremely windy and the yard stick was even blowing away :^).

DSCN0863_zpsa3b41ee2.jpg

Piece 1 (left on first photo)

DSCN0864_zps0b88978a.jpg

Piece 2 (right)

DSCN0868_zps458f0627.jpg

More detail of the one on the right;

DSCN0866_zps0200de33.jpg

Edited by Roadrunner

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Roadrunner

One of the 3 smaller finds;

This side looks wood-like;

DSCN0877_zpsc7c615a5.jpg

This side (same rock) looks plain;

DSCN0881_zps2aeeb2a3.jpg

A different sample side view;

DSCN0896_zpsa3d38d40.jpg

Other side;

DSCN0893_zpsa2670fb9.jpg

...and one end;

DSCN0894_zpsda16bf71.jpg

I believe this last one is chalcedony - and I don't know if the bands are indicative of anything but a geological process. It is very heavy and dense;

DSCN0890_zpsdee38cf3.jpg

...another side;

DSCN0885_zps3d9eb494.jpg

...and one more side;

DSCN0884_zps342c2eeb.jpg

Any help at all will be highly appreciated!

Edited by Roadrunner

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Roadrunner

Now I'm thinking the last one might be "rainbow obsidian."

Anyone?

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Wrangellian

Most if not all of those look like pet. wood to me - different states of preservation and weathering. See what others say..

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Roadrunner

Most if not all of those look like pet. wood to me - different states of preservation and weathering. See what others say..

Thank you for your input. If only I could get some others to say something! :)

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Wrangellian

Maybe give it some time. But I'll assume everyone agrees with me otherwise they would pipe up!

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Mr_ed

Post no 11 looks like a gastropod. I have one similar.

Ed

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Mr_ed

I'd say the first pictures are petrified wood.. not sure about no 5.. and 6 I would say no at this point..not wood .. the last three look like agate..the the 2nd last one and the third last one look like the same piece and may be agatized wood... don't see any obsidian but I've been wrong before..

Ed

Edited by Mr_ed

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Roadrunner

Thank you Wrangelian and Mr._Ed.

The last 3 pictures are in fact the same "rock."

At first I thought it was petrified wood, then when I started researching I found rainbow obsidian looking like it. I suspect that if I broke it open it would look like chalcedony, as we tend to have a lot of that over here. The banding is the biggest difference on this piece. I may run a density test on it with water displacement, as it is quite heavy.

I also have no idea where to start trying to find out what kind of petrified wood all those pieces might be. They all look very different. The first one on post 87 is the most unique looking - I don't think that I've ever seen a piece of petrified wood look like that.

Thanks again - your thoughts or ideas, as well as anyone elses are very much appreciated!

Edited by Roadrunner

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Roadrunner

Another type of sponge or bryozoan?

DSCN0925_zpscf23a01d.jpg

I can't find anything like it.

There are a couple more pictures, but none that show the ruler very well. The entire piece is 4-inches by 3-inches, and nearly 2-inches in depth. The fossil is about 1 1/4 inches long and 1/2 inch wide.

DSCN0923_zpsa2704d64.jpg

DSCN0922_zpsa0bc719f.jpg

The matrix material is limestone with about a 1/4-inch layer of silicified chert marbled with quartz covering it. There are also a very small traces of columnal crinoids and probably a small trace profile of a bivalve that can be seen in the lower right hand corner of the picture directly above. The fossil itself appears to be limestone.

Edited by Roadrunner

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squalicorax

Very nice fossils! I must say those mountain weathered rocks always look bizarre.

I think your last item is a very weathered crinoid stem.

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Roadrunner

Very nice fossils! I must say those mountain weathered rocks always look bizarre.

I think your last item is a very weathered crinoid stem.

Thank you!

We do get a lot of columnal crinoids around here.....it just seemed the layers looked different than most of the stems, or stem traces that I've found - smaller layers than most, especially for such a large piece.

My biggest problem in this area is that it is so diverse - many different periods all merging into one area creating a lot of detritus. But this area is right outside my door, so to speak. So I guess that I shouldn't complain ^_^. We are going to make a specific trip to an area west of here within a couple of weeks.

And I've only put in here what I'm not sure about. I've been telling myself that I should start a gallery for some of the nicer and more identifiable pieces. The stromatoporoid that was looked at by the museum was the biggest mystery for a couple of years (until they got out here). But it is too heavy for me to get it home. :wacko: Did you see the thread on that?

Gotta' go until later! Thank you, again.

Edited by Roadrunner

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howard_l

I don't see anything that makes me think bryozoan , It does look a little like a crinoid. Do you know what age it is, that could help. If you are finding other crinoid material id say that is what it is.

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mammothhunter

I just wanted to chime in on the first photos:

Looks like a pseudomorph of quartz replacing another mineral. Might be entirely calcite. Drop some vinegar on it and see if you see any bubbles form. If not, I would say a quartz pseudomorph.

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Roadrunner

I don't see anything that makes me think bryozoan , It does look a little like a crinoid. Do you know what age it is, that could help. If you are finding other crinoid material id say that is what it is.

Post #17 on page 4 of this thread (one page back) describes the area. It has a lot of period diversity. Not more than 4 miles from our home a (jurassic) mammoth was found in the 1970's. Another found in a gravel pit about 5 miles from us.

But from the stromatoporoid (My First Mystery) to most fossils that I've found in the immediate area - they all seemed to be marine bivalves, reef builders, and rugose corals. Of course, then there are the petrified wood pieces. (sigh).

Thank you for looking! :)

Edited by Roadrunner

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