Impact melt page

Exactly the information we need to identify impact sites!


Fig. 1. Mien (Sweden) impact structure; impact melt rock; polished section <13 cm>.


Fig. 46 – 1. Blue glass with shocked rock and metallic inclusions, Saarland impact. (image Berger 2014)

I know lots of "explosion breccia" is volcanic, so there is a possibility of it being that, also. Do you know where it was found, and is the location it was found near a known impact site? It does look a lot like many of the breccias I find here, seeming andesite or other fine grained granitic type rock partially melted in a green melted base of some sort (jasper-like though what I find here tends to be around mohs 6 to 7). I see yours has a few conchoidal fractures, one fairly large, and others very small on the edge. The colors are similar to what I find here too, that chloritic blueish green is classic. The problem I have with identifying stuff here is that this area was also the site of a huge volcanic range in ancient times, and some even believe that the Sudbury Impact was severe enough to touch off those volcanoes as a reaction... So it could be for your piece here... only I would suspect if it was impactite that the event happened much more recently since the piece does not show a great deal of wear and the edges remain sharp. The stuff I have has been glacier worn and water worn for centuries, and yours is a different animal. There is brecciated limestone in some places, even shattered fossils from more recent impacts, ( you know, only a few hundred thousand to a million years ago- instead of a hundred million, eh?)
Relying on photos of known
impact materials can be tricky since there is always a range of material present on any impact site, and some can look the same as volcanic material to the naked eye. Generally impactite is confirmed by microscope examination of quartz particles, looking for shattered quartz on the microscopic level. Scientists today tend to agree shocked quartz can only come from impact, and are not created by volcanic actions. Another good sign is if the breccia is found with or near shatter cones. Like shocked quartz, it is also believed that shatter cones are only created by impacts, and not through volcanic action. Something else to look for is tiny metallic inclusions. Most impact sites and materials have a good deal of nickel/iron from the original impactor. Regarding the glacial erratics I find, I can only say I suspect or believe it is melt glass or melt rock due to impact, but it is very hard to be 100 percent certain. This is still such a new field of identity, and scientists are changing their minds every day about many of the processes involved in impact melting and shattering and the results of such on the rocks, the geology, the climate and atmosphere, etc at the time the impacts happen. All that said, that's a really great piece of breccia! Looking forward to hearing more about where this was found and any other information you can tell us.

Great site James. I like impactite as well as the meteorite itself.

www.impact-structures.com/wp-content/uploads/2011/12/54-charle-300x184.jpg

this one has the very sharp edges like yours above does, as well as a melt glass infilling between the shards.

This is what i can see with my eyepiece. Around the edge of the unknown material and the breccia is a very very thin white-milky fortification line and in the breccia itself, it looks like silver melted on? or mixed in. I picked it out of a hillside buried in with basalt and ash-dirt and it didnt fit with what we were digging for,thats why i kept it. I know the area once was volcanic, so an impact site would be unknown if there was one. 
It does look familiar to what your showing me in your finds, except yours are very well tumbled by natural forces. No crystals I can see in mine.
Thanks Snowmom!

Been there done that. How do you put a price on some stones that are way rarer than diamond ??
strange situation. All unusual and rare should start at $500/carat. ha, don't work that way.
people on this forum would all be billionaires

I questioned that thought myself many times. Diamonds are so abundant and expensive when compared to other precious and non precious stones that are rare to find. Its beyond me.

What a difference a conglomerate makes,
24 trillion dollars overcomes sunshine and flowers . . .