Bev Posted May 15, 2016 Share Posted May 15, 2016 Group Hunt 5.14.16 SE MN Galena Formation Ordovician I'm thinking perhaps a broken trilobite cephalon, but it could be a broken brachiopod shell too... For Scale Closeup Thanks for looking! :-D The more I learn, I realize the less I know. BluffCountryFossils.NET Fossil Adventure Blog Go to my Gallery for images of Fossil Jewelry, Sculpture & Crafts Pinned Posts: Beginner's Guide to Fossil Hunting * Geologic Formation Maps Link to comment Share on other sites More sharing options...
Fossildude19 Posted May 25, 2016 Share Posted May 25, 2016 Just came across this. Not sure about this one, Bev. May need some prep/matrix removal, to make a definitive ID. Regards, Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
Guguita2104 Posted May 25, 2016 Share Posted May 25, 2016 (edited) Hello Bev! I agree with Fossildude19 on the preparation, but it's possibly either (you know I'm not an expert at all) an eroded crinoid calyx or a brach shell. Regards, Guguita Edited May 25, 2016 by Guguita2104 Link to comment Share on other sites More sharing options...
Bev Posted May 25, 2016 Author Share Posted May 25, 2016 Thank guys! I did work on it a bit and now I'm thinking brach shell too. :-( The more I learn, I realize the less I know. BluffCountryFossils.NET Fossil Adventure Blog Go to my Gallery for images of Fossil Jewelry, Sculpture & Crafts Pinned Posts: Beginner's Guide to Fossil Hunting * Geologic Formation Maps Link to comment Share on other sites More sharing options...
abyssunder Posted May 26, 2016 Share Posted May 26, 2016 (edited) Hello Bev! I agree with Fossildude19 on the preparation, but it's possibly either (you know I'm not an expert at all) an eroded crinoid calyx or a brach shell. Regards, Guguita Crinoid calyx was also my thought. Or maybe a holdfast. (?) This is just an example of holdfast, not for a precise ID : http://drydredgers.org/crinoids_disparida.htm Edited May 26, 2016 by abyssunder 2 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
fifbrindacier Posted May 26, 2016 Share Posted May 26, 2016 Hi Bev. I don't see a cephalon here, nor a brachiopod. I'd rather follow Guguita and Abyssunder. 1 "On ne voit bien que par le coeur, l'essentiel est invisible pour les yeux." (Antoine de Saint-Exupéry) "We only well see with the heart, the essential is invisible for the eyes." In memory of Doren Link to comment Share on other sites More sharing options...
kurdelmb Posted May 30, 2016 Share Posted May 30, 2016 Hi Bev! Since we live so close to each other I have to ask. How confident are you about this being Galena? It sure looks a lot like the Elgin member of the Maquoketa formation. Just a thought. It may help narrow the search down a bit. 1 Link to comment Share on other sites More sharing options...
Bev Posted May 31, 2016 Author Share Posted May 31, 2016 Hi Bev! Since we live so close to each other I have to ask. How confident are you about this being Galena? It sure looks a lot like the Elgin member of the Maquoketa formation. Just a thought. It may help narrow the search down a bit. We do have the Maquokena shale here, but I have never heard of the Elgin member of the Maquoketa! Where it was collected, all three members of the Galena Formation are present: Stewartville, Prosser and Cummings or Cummingsville, anyway the bottom. However, the Maquoketa and Decorath shale are on top of the Galena. That said, there could be some of that shale on top, but I am NOT climbing the sheer rock face to find out, and above is private land. Would love to hear more of this Elgin member of the Maquoketa. I always love to learn new things! :-D 1 The more I learn, I realize the less I know. BluffCountryFossils.NET Fossil Adventure Blog Go to my Gallery for images of Fossil Jewelry, Sculpture & Crafts Pinned Posts: Beginner's Guide to Fossil Hunting * Geologic Formation Maps Link to comment Share on other sites More sharing options...
doushantuo Posted May 31, 2016 Share Posted May 31, 2016 (edited) http://www.kgs.ku.edu/General/Personnel/klm/GAL/Raatz_Ludvigson_1996_GSA_SpcPub.pdf http://opus.ipfw.edu/cgi/viewcontent.cgi?article=1223&context=geosci_facpres http://www.journaltaphonomy.com/JT-articles/2006/4/jt049-web.pdf https://www.ideals.illinois.edu/bitstream/handle/2142/43147/faciesanalysisof547grae.pdf?sequence=2 http://www.bioone.org/doi/pdf/10.1666/0022-3360(2001)075<0370%3AFCFTUO>2.0.CO%3B2 The Galena is of course famous for its Zn-Pb mineralogy Edited May 31, 2016 by doushantuo 2 Link to comment Share on other sites More sharing options...
Bev Posted May 31, 2016 Author Share Posted May 31, 2016 Fascinating! In the very first PDF it showed only one spot where the Elgin member of the Maquoketa is exposed in Fillmore County, MN. I was no where near that spot at the time of collection. However, I was yesterday... :-D This is the photo that was created by Caleb, whose father is a geologist, for this area. On here the Maquoketa is ABOVE the Galena. In some of the PDFs, they are putting the Maquoketa BELOW the Galena. Now, I'll admit I have a small pea brain, but Caleb was the EXPERT on the SE MN area. He would know if it was above or below and allowed me to copy this image from his website that his geologist father oversaw. What I believe I think I am understanding, is that in Fillmore County MN we have only one tiny area where the Elgin member of the Maquoketa is exposed. That is a tiny area where there are only one or two rock exposures that are accessible to the public - right of way. :-) Am I missing something??? Lord knows, the more I learn the less I know... 2 The more I learn, I realize the less I know. BluffCountryFossils.NET Fossil Adventure Blog Go to my Gallery for images of Fossil Jewelry, Sculpture & Crafts Pinned Posts: Beginner's Guide to Fossil Hunting * Geologic Formation Maps Link to comment Share on other sites More sharing options...
kurdelmb Posted June 2, 2016 Share Posted June 2, 2016 Bev - The Elgin member is the base layer of the formation and lies directly on top of the Galena in most areas (I am not familiar with any unconformities that may come into play in your area). It is quite often referred to as shale but the vast majority of the Elgin is very hard limestone with some shale. The lowest portion of the Elgin is quite hard and has a distinctive brown/dark tan color (in our area anyway) Yes, for sure the one guy that would know would be Caleb. I know Al Sheer has collected extensively in both the Elgin and Clermont members of the Maquoketa. If you have a number for Al he could most likely assist. This pdf pertains to Iowa but it would be a good reference for understanding the formation. It has been very useful to me over the years. PDF LINK 1 Link to comment Share on other sites More sharing options...
Bev Posted June 2, 2016 Author Share Posted June 2, 2016 GREAT PDF!!! Thank You!!! :-D The more I learn, I realize the less I know. BluffCountryFossils.NET Fossil Adventure Blog Go to my Gallery for images of Fossil Jewelry, Sculpture & Crafts Pinned Posts: Beginner's Guide to Fossil Hunting * Geologic Formation Maps Link to comment Share on other sites More sharing options...
doushantuo Posted June 2, 2016 Share Posted June 2, 2016 http://pubs.usgs.gov/pp/0274k/report.pdf Link to comment Share on other sites More sharing options...
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