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The_Piper wrote:Thanks guys. Speculate away Theropod, I'm learning new stuff As long as you don't mind.
I've been busy trying to find out the age of the rocks around here. I finally found this map http://www.maine.gov/doc/nrimc/mgs/explore/bedrock/facts/geol-hist-1.htm and I'm certain that I lie either in the area of middle Ordovician to middle Devonian, or Cambrian to middle Ordovician. That map has no reference points, and I am near the border of the 2 zones.
Also, this region was affected by glaciers. There is vertical strata along the same brook...by strata I mean the layers of sediment in boulders, etc, that are visible in lines
The rock seems like a ball of igneous rock with sedimentary rocks stuck to the outside. I know little more than that for terminology unfortunately. The igneous rock looks and feels like granite, but it "glistens" more, is darker, and looks like it might be more dense. The "teeth" also look like granite, of a lighter, more familiar color than in between the teeth. They also "glisten". It's appears to be 4 different small rocks stuck to the outside. It's a little dirty from brook sediment. I turned it over on it's side and a small piece of the corner flaked off from the darker colored sedimentary rock. It revealed a reddish stain on the interior. I see that a lot with sedimentary rocks found in the area. There is a dark flaky sedimentary rock on both flat sides, and also a gray colored rock on both sides that is more solid. I think it is sedimentary also because I found another rock in the brook with definite fossils in this type of rock. It looks somewhat like compressed beach sand.
I might have some luck finding someone in the area with at least a little working knowledge, but no one I can think of yet. Population here, 247
I took many more pictures, but my camera is pretty lousy at close-ups.
Here is the other fossil I found, about 10-15 yards downstream, and 3 years prior.
Top
http://xs.to/image-4721_4B729C91.jpg
Bottom
http://xs.to/image-F459_4B729C91.jpg
Edit: Edited on behalf of the Op - Mazille
Is the layers sandwiching the the "teeth" layer both the same type of rock?
Try this on the non-tooth layers. As a test you could try a 3 part water one part white vinegar etching. If you can form a masking "dike" with warm wax, and then allow to cool, so that only a small portion of the surface can be exposed to the acid you can find out if the stone is of a limestone composition. If the rock is limestone it will react with a fizz. When the fizzing stops clean off the wax damn/dike, wash the area with a baking soda water (1 part soda 5 parts water by volume acid neutralizer), allow to dry, and examine the etched area with as high power magnifier as you can. Report what you see, and the reaction to the acid solution. This weak solution should only clean the area and not erode the rock to any great extent. If the rock is non reactive we need to take another tack.
The_Piper wrote:Thanks guys. Speculate away Theropod, I'm learning new stuff As long as you don't mind.
I've been busy trying to find out the age of the rocks around here. I finally found this map http://www.maine.gov/doc/nrimc/mgs/explore/bedrock/facts/geol-hist-1.htm and I'm certain that I lie either in the area of middle Ordovician to middle Devonian, or Cambrian to middle Ordovician. That map has no reference points, and I am near the border of the 2 zones.
Also, this region was affected by glaciers. There is vertical strata along the same brook...by strata I mean the layers of sediment in boulders, etc, that are visible in lines
The rock seems like a ball of igneous rock with sedimentary rocks stuck to the outside. I know little more than that for terminology unfortunately. The igneous rock looks and feels like granite, but it "glistens" more, is darker, and looks like it might be more dense. The "teeth" also look like granite, of a lighter, more familiar color than in between the teeth. They also "glisten". It's appears to be 4 different small rocks stuck to the outside. It's a little dirty from brook sediment. I turned it over on it's side and a small piece of the corner flaked off from the darker colored sedimentary rock. It revealed a reddish stain on the interior. I see that a lot with sedimentary rocks found in the area. There is a dark flaky sedimentary rock on both flat sides, and also a gray colored rock on both sides that is more solid. I think it is sedimentary also because I found another rock in the brook with definite fossils in this type of rock. It looks somewhat like compressed beach sand.
I might have some luck finding someone in the area with at least a little working knowledge, but no one I can think of yet. Population here, 247
I took many more pictures, but my camera is pretty lousy at close-ups.
Edit: Edited on behalf of the Op - Mazille
The_Piper wrote:
Here is the other fossil I found, about 10-15 yards downstream, and 3 years prior.
Top
http://xs.to/image-4721_4B729C91.jpg
Bottom
http://xs.to/image-F459_4B729C91.jpg
To me it looks likes a brittle layer (in the middle), possibly a vein of calcite, has fractured due to compressive forces and a different mineral that is more resistant to erosion or dissolution has been deposited in the fractures. Differential weathering has produced the tooth-like appearance due to the later formed fracture filling material being more resistant.
theropod wrote:
Do you have a good temporal setting for these fossils, or is this coming from several erosional settings?
I know the ammonite can be no younger than the Late Cretaceous. Can I get a top view of that ammonite, please?
jaydot wrote:you lucky blighter, you have all sorts of interesting stuff lying around. the first set of pix, i would suggest have some ferrous content. bits of it look like iron from here, but with only two pix, it's not possible to be certain.
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