Any geologists out there?

[OntarioHunter]

I found this rock when hunting a small section of Montana block management last fall. Interesting. Wondering if the white pieces are fossils. There is every type of formation in the area: igneous pillow basalt (the oldest rocks), sedimentary, metamorphic, and lots of glacial debris thrown on top. A ways further down the road I found an erratic boulder of same material. Any theories?

 

[Schaaf]

Can you post a better pic of the smaller fragments? Most likely not a fossil and sedimentary but I can’t say for sure off that picture.

 

[Wildabeest]

Looks like a petrified campfire turd to me...

 

[TOGIE]

Looks like plagioclase crystals...

def not fossils

better pics would help, but I’m feeling good on plagioclase phenocrysts in basalt

 

[OntarioHunter]

Here's some close up pics. I thought the rock was basalt but had never seen crystals like that. And on the end where they are fractured lengthways they look very much like petrified wood fragments. Anytime one looks down in that country there's interesting rocks to see. Petrified wood, agate, and fossils.

 

[TOGIE]

yeah, still looks like classic plagioclase crystals to me. groundmass is up for debate - though for certain it's not sed or metamorphic.

to me it's either basalt or a volcaniclastic, my money is still on basalt.

and to be sure, still a great find, i definitely would've packed that rock out. and full disclosure, i have a degree in geology, but i'm not a geologist

 

[huronmtns]

Here are a couple that I have found on the shoreline of Lake Superior. I'm not sure what these are either.
# 1.

# 2.

 

[TOGIE]

Here are a couple that I have found on the shoreline of Lake Superior. I'm not sure what these are either.
# 1.
View attachment 171244
# 2.
View attachment 171248

this is fun

my guess on number one is a fluvially transported piece of a silica cemented conglomerate composed of a potential menagerie of similarly fluvially transported metamorphics, igneous, volcanics, or seds (probably not seds though). hard to tell what exactly the rocks that comprise it actually are without real close inspection

number 2 actually looks like a fluvially transported (therefore rounded) version of the OPs rock

 

[gouch]

It looks like leaverite to me.

 

[blueridge]

my guess on number one is a fluvially transported piece of a silica cemented conglomerate composed of a potential menagerie of similarly fluvially transported metamorphics, igneous, volcanics, or seds (probably not seds though).

You took the words right out of my mouth. (Gonna have to memorize that string so I can appear much smarter than I am.)

Cool rocks! (The extent of my expertise.)

 

[OntarioHunter]

And there's this one I photographed near Dillon elk hunting. I was on or near a mining claim so did not pick it up. Looks somewhat like Lake Superior "pudding stone". About the size of a softball as I recall.

 

[Carl 9.3x62]

Not sure how the rules read in MT, but it would have been illegal to take it WY. Still a cool rock though.

 

[elkantlers]

Looks like Breccia. A type of conglomerate that has broken, irregular fragments cemented together.

 

[OntarioHunter]

Not sure how the rules read in MT, but it would have been illegal to take it WY. Still a cool rock though.

Mining claimant owns the mineral rights which includes all rocks, surface or underground. It's federal law.

I am a mining business historian, PhD.

 

[huronmtns]

Yooperlites

 

[Carl 9.3x62]

Mining claimant owns the mineral rights which includes all rocks, surface or underground. It's federal law.

I am a mining business historian, PhD.

Just coming from the angle that when hunting on hunter management areas (Wyoming's equivalent to MT block management areas, more or less) you only have permission to be on the private land to hunt which ever animal you are hunting. You don't have permission to pick up rocks, antlers, flowers, etc... Again, I don't know what Montana's regulations say, but it's just something to keep in mind.

 

[OntarioHunter]

Just coming from the angle that when hunting on hunter management areas (Wyoming's equivalent to MT block management areas, more or less) you only have permission to be on the private land to hunt which ever animal you are hunting. You don't have permission to pick up rocks, antlers, flowers, etc... Again, I don't know what Montana's regulations say, but it's just something to keep in mind.

Technically, you may be right. Unless I owned the mineral rights, I had no right to remove rocks from the rancher's property ... if it was his property. May have been BLM or state school land that rancher was leasing. A lot of it in that area. But also a lot of gas and oil so someone surely owned the mineral rights. And that someone was not me. This specimen is obviously of no mineral value so I'm sure no one would object to my picking up one less rock to dull the cultivator.

 

[Dunning Kruger]

Here are a couple that I have found on the shoreline of Lake Superior. I'm not sure what these are either.
# 1.
View attachment 171244
# 2.
View attachment 171248

Second one looks like somebody ate too many peanuts and took a dump on the shore of lake superior

 

[Nemont]

Hiking in the Mo. Breaks one can find a lot of interesting rocks.


These always intrigue me, the arid landscape used to be a sea bed, seems hard to be imagine

 

[Irrelevant]

yeah, still looks like classic plagioclase crystals to me. groundmass is up for debate - though for certain it's not sed or metamorphic.

to me it's either basalt or a volcaniclastic, my money is still on basalt.

and to be sure, still a great find, i definitely would've packed that rock out. and full disclosure, i have a degree in geology, but i'm not a geologist

Coming from the land of basalt, I'm leaning towards some other mafic igneous matrix. But it may just be that I'm too used to our basalt which has very few phenocrysts beyond the occasional bit of olivine.

I too have a degree, and sometimes still wear that hat, but not all that often, and hardrock was never my focus.