A Funny Rock from the River. HaHa

[roustabout149]

I told my Grandson to put it back...but he just wouldn't listen! I created a young rock hound. :laugh: Now what am I going to do??? Help! heehee inch:

[CMD]

Neat rock for your grandson to pick up! Looks like conglomorate, pebbles embedded in sandstone, but your friend from across the Big Pond will fill ya in........

[roustabout149]

CMD wrote:

Neat rock for your grandson to pick up! Looks like conglomorate, pebbles embedded in sandstone, but your friend from across the Big Pond will fill ya in........

  This rock makes me laugh.  It is a neat rock...and he insisted upon bringing it home!  It has rocks on the other side also.  Rocks upon rocks!!! :laugh:  :laugh:

[CMD]

I'm hoping it's conglomorate, and not just pebbles embedded in cement! Anyway, what's his face will know, if he sees the thread, or you can just ask him.....

[painshill]

CMD wrote:

I'm hoping it's conglomorate, and not just pebbles embedded in cement! Anyway, what's his face will know, if he sees the thread, or you can just ask him.....

  "What's his face" indeed? Who can you mean, Charlie? I'll be resigning from the forum forthwith. As Groucho Marx said: "I wouldn't want to belong to any club that would have me as a member!" :laugh:
Anyway, back to the rock. To be completely honest, conglomerate and concrete can look awwwwwful similar in a picture, but I zoomed in as much as I could and I don't think I see sand and cement, so I'm going to assume that it's not concrete. It's an interesting rock, for a number of reasons. I’m so glad he got to keep it, Pam.
It has a coarse sandstone matrix with clasts of other rocks embedded in it. Sedimentary origin. A lithified gravel.
The clasts however, are igneous and a mixture of rock types, so we would use the term “polymict”. If the clasts were rounded pebbles, we would normally use the term “conglomerate”, and if they were angular, we would normally use the term “breccia”. The rock contains both rounded pebbles and angular clasts, so it’s a “polymict conglomerate-breccia”.
Here's a section through a more conventional conglomerate from my collection. Note the very rounded clasts... this stuff is known as Hertfordshire Puddingstone:

Your grandson's specimen has quite a range of clast sizes, so geologically we would call it “poorly-sorted”. It’s also what is known as “matrix-supported” rather than “clast-supported”… that is, its structural integrity comes from the fact that the clasts are completely surrounded by finer cemented material rather than its strength coming from dense packing of the clasts.
All of these features are highly characteristic of a particular kind of conglomerate which arises from direct glacial deposition. Unsorted glacial sediment is known as “till”, so when it lithifies after being deposited, we call the resultant rock “tillite”. I’m pretty sure that’s what it is.
What's-his-Face (from the other side of the big pond).

[CMD]

Sorry, Roger. Being tested for MCI next month. I believe your're the most valued member on this forum, who cares whether I can remember a name or not? Why don't you stick around. I'd much rather leave then see this forum severely diminished by your absence......
A numbskull from Little Rhody...

[roustabout149]

Cool, Roger!  I had no idea!  And to think, me of all people, would have had him leave it at the river!? :blink:  He will be quite excited to know how this rock was formed.  He will laugh at me.  You know that, don't you?  Thanks for being here!!!
Pam

[painshill]

Yes-siree, Pam. Get him all fired up with enthusiasm and let him bring home everything his little pockets will carry. By the time he's all growed up he may have the biggest collection of [strike]concrete[/strike] - I mean conglomerate - east of the Missouri. He'll be able to build his own house! :whistle:
Charlie... I answer to anything. You shoud hear what my wife calls me. Oh. Let's not go there. :laugh:  :laugh:  :laugh:
The token Limey.
aka what's-is-name.

[roustabout149]

painshill wrote:

Yes-siree, Pam. Get him all fired up with enthusiasm and let him bring home everything his little pockets will carry. By the time he's all growed up he may have the biggest collection of [strike]concrete[/strike] - I mean conglomerate - east of the Missouri. He'll be able to build his own house! :whistle:
Charlie... I answer to anything. You shoud hear what my wife calls me. Oh. Let's not go there. :laugh:  :laugh:  :laugh:
The token Limey.
aka what's-is-name.

  I'll call you, "painshill." Now you are confusing me.  Were you testing my gullibility?, or did he bring home a piece of concrete?  Actually would make a decent rock house! :blink:

[painshill]

[QUOTE]roustabout149 wrote:

Yes-siree, Pam. Get him all fired up with enthusiasm and let him bring home everything his little pockets will carry. By the time he's all growed up he may have the biggest collection of [strike]concrete[/strike] - I mean conglomerate - east of the Missouri. He'll be able to build his own house! :whistle:
Charlie... I answer to anything. You shoud hear what my wife calls me. Oh. Let's not go there. :laugh:  :laugh:  :laugh:
The token Limey.
aka what's-is-name.

  I'll call you, "painshill." Now you are confusing me.  Were you testing my gullibility?, or did he bring home a piece of concrete?  Actually would make a decent rock house! :blink:
  No, not teasing you Pam. I do think it's tillite from glacial deposition. But if he brings back everything that looks like pebbles in matrix he's gonna hit the concrete motherlode sooner or later. :laugh:
Roger