colebiederman Posted July 12 Share Posted July 12 When hunting road cuts and the like, how can one tell which formation a certain rock or fossil came from? I know that there is different stratigraphy and certain formations yield specific fossils and contain specific rock types, but in my experience so far, there is a lot of overlap. When hunting a road cut that exposes several formations, is there a sure fire way to be able to tell what formation a rock came from? I'm asking because the road cuts I have looked at so far are fairly jumbled, and rocks obviously fall down and erode over time, so they are not always where the formation is suppose to be. If anyone could help me out, that would be awesome. I know it isn't as easy as looking at a rock and 'just knowing', but I am willing to learn and eager to hear back from more experienced people than me. Thank you! Link to comment Share on other sites More sharing options...
DPS Ammonite Posted July 12 Share Posted July 12 Read and study the professional literature. Search for papers on specific rock units and formations by using Geolex. Example: use search terms Naco and geolex. https://ngmdb.usgs.gov/Geolex/UnitRefs/NacoRefs_9476.html 1 My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
FranzBernhard Posted July 12 Share Posted July 12 (edited) 5 hours ago, colebiederman said: When hunting a road cut that exposes several formations, is there a sure fire way to be able to tell what formation a rock came from? Rarely. Sometimes, some beds are very distinctive. More often, its difficult and often, it is impossible to assign a individual rock specimen out of context to a specific formation. Unless there is a characteristic fossil in this specimen. Exercice: Go to a well-documented site with clear formation boundaries and sample that area systematically and extensively. At home, compare the rocks from each formation in detail. Franz Bernhard Edited July 12 by FranzBernhard Link to comment Share on other sites More sharing options...
Ludwigia Posted July 12 Share Posted July 12 I concur with the above advice. The problem is that some formations sometimes have differing lithological components within themselves while at the same time different formations may have almost the same type of lithology. If a loose fossil is found in matrix, then you can make comparisons, if not, then it could be difficult, since many fossils can be found in all of the local formations. So, as mentioned above, study, study, study, learn, learn, learn. 1 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Ludwigia Posted July 14 Share Posted July 14 @colebiederman Have any of these responses been of help to you? It would be nice to have some kind of reaction from you. 1 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Fossildude19 Posted July 14 Share Posted July 14 LINK 1 LINK 2 Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 IPFOTM -- MAY - 2024 _________________________________________________________________________________ "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...
colebiederman Posted July 16 Author Share Posted July 16 On 7/14/2024 at 6:22 AM, Ludwigia said: @colebiederman Have any of these responses been of help to you? It would be nice to have some kind of reaction from you. Yes I’m sorry for the late reply, life has been busy. They’ve been incredibly helpful, I appreciate all the info. Once things settle down I plan on sitting down and taking some notes on the topic. On 7/14/2024 at 7:01 AM, Fossildude19 said: LINK 1 LINK 2 Thank you! 1 Link to comment Share on other sites More sharing options...
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