Search the Community

Fossilized Cicada Entombed In Opal Reveals Precious Gems Can Contain Ancient Life Rachael Funnell, IFL_Science, October 7, 2023 https://www.iflscience.com/fossilized-cicada-entombed-in-opal-reveals-precious-gems-can-contain-ancient-life-57413 Rare Fossil Reveals Cicada Entombed in Opal An insect trapped in a precious gem points to new places to search for ancient life Carolyn Wilke, Scientific American https://www.scientificamerican.com/article/rare-fossil-reveals-cicada-entombed-in-opal1/ The open accesspaper is: Chauviré, B., Houadria, M., Donini, A. et al. Arthropod entombment in weathering-formed opal: new horizons for recording life in rocks. Sci Rep 10, 10575 (2020). https://doi.org/10.1038/s41598-020-67412-9 Yours, Paul H.

Hello all, A few months back I happened upon an intriguing rock while taking a walk in the woods. The main groove on the front of the rock struck me as a possible trace fossil (perhaps a worm burrow or a tunnel created by plant roots). I considered the possibility that it could potentially be a fossil since it was found in the Newark Supergroup of northern Virginia which is know to have some fossiliferous rocks. However, I fully expect that it is simply an artifact of weathering or that it has a geologic origin. Can any confirm whether it is a trace fossil or simply a case of weathering? I’ll tag a few members that I feel are knowledgeable on this subject: @Fossildude19 @EMP @cck @WhodamanHD I deeply appreciate all input.

I found this near Camp Verde, AZ in a creek....area known as Apache area. Just looked different, any ideas?

Hello. I was just curious about what some good techniques for artificially weathering a concretion to get them open are? I've read that the best way to go is to soak, freeze, thaw, and repeat. But none of the sources I've read describes how long that takes. I'm sure it varies from specimen to specimen but is this process weeks, months or years? Does anyone have any other methods or resources about the process? I was thinking of giving it a try and could use some more information on the process. It seems kind of like the old geode gamble in a way. There's no way of knowing what's inside unless it's partially exposed already. I don't have a geologist's hammer and I think I'd feel bad if I cracked one by hitting it too hard or at the wrong angle. Are there any other tools that are recommended?

Scientists Waited Two and a Half Years to See whether Bacteria Can Eat Rock. The mystery of dirt’s origins is a thorny experimental problem. Jennifer Frazer, May 1, 2020 https://blogs.scientificamerican.com/artful-amoeba/scientists-waited-two-and-a-half-years-to-see-whether-bacteria-can-eat-rock Napieralski, Stephanie A., Heather L. Buss, Susan L. Brantley, Seungyeol Lee, Huifang Xu, and Eric E. Roden. "Microbial chemolithotrophy mediates oxidative weathering of granitic bedrock." Proceedings of the National Academy of Sciences 116, no. 52 (2019): 26394-26401. https://www.academia.edu/41372966/Microbial_chemolithotrophy_mediates_oxidative_weathering_of_granitic_bedrock https://www.pnas.org/content/116/52/26394 Yours, Paul H.

I’m going through my finds from my last hunting trip and came across these brachiopod valves that I picked up. I grabbed them, not because they were the best preserved finds of the day, but because they are the worst. To clarify, I believe the initial preservation wasn’t too bad, but it’s the weathering and subsequent degradation of the fossil that caught my interest. Most valves that I find in the area (Upper Ordovician road cut) are in pieces. I presumed it was because the valves weathered out of the matrix and THEN were washed around by rain run off, trampled, exposed to the elements, etc. before breaking into pieces. However, these valves are cracked while still being attached to the underlying matrix. They remind me of mud that has dried in the sun. It seems to show that some of the valves at least cracked and split BEFORE coming completely out of the matrix. Then they weather out in pieces. I find it interesting to see examples of them in the middle of the process. The matrix looks like dirt in the picture, but it is hard as rock and the valve fragments are stuck fast. I think this is what is known as mudstone(?). I’m sure the fragments would come off with a little dental pick work, but they are not so loose as to brush off or come off by picking with the finger nail.

This post is about a fossil look alike, or to quote my kid, "a foss ilarm". Earlier this year I was scratching my head about stromatolites, stromatoporoids, and algae and coral in general. It started with finding what I dubbed "the sandwhich rock" (first 3 pics) at a roadcut in Blair County, central Pennsylvania (US). The outcrop is Mifflintown-Bloomsburg (undivided). My best guess is this form the Mifflintown part. Friends that know their stuff told me about "honeycomb weathering". Besides the Wikipedia article, there is more than I ever wanted to know in the Treatise on Geomorphology Volume 4, Weathering and Soils. I returned to the site and took more photos. This outcrop is on a very busy city highway and just below a freeway overpass. I wanted to know if the weathering is just from modern-day exposure, so I poked at the rock layer until I found a piece that was still in place, but loose. To my surprise, it was olive brown and pitted like this all the way around, even the back side which had not been exposed to wind/sun. I removed that piece and cracked it open.... and was even more surprised to find the inside of the rock is light grey with brachiopods and broken trilobite bits. it failed the vinegar test (no fizz). The inside of the rock looked untouched, to my noobie eye. And that makes me think that all this pitting is from very recent time. In my superficial reading, I've seen frequent references to salt as a common factor in weathering. Even though the backside of the rock was still really pitted (R side of pic with my fingers), there is probably a lot of highway salt that makes it way into the soils and float on the face of the outcrop. Is it a player? Beats me, I've gone as far as I can thinking about this. Except to note my extreme-environment microbiologist wife always likes to say "microbes rule all!!"

Weathering of rocks by mosses may explain climate effects during the Late Ordovician, Stockholm University, July 7, 2016 http://www.aces.su.se/weathering-of-rocks-by-mosses-may-explain-climate-change-during-the-late-ordovician/ https://www.sciencedaily.com/releases/2016/07/160707101029.htm The paper is: Porada, P., T. M. Lenton, A. Pohl, B. Weber, L. Mander, Y. Donnadieu, C. Beer, U. Pöschl, A. Kleidon. High potential for weathering and climate effects of non-vascular vegetation in the Late Ordovician. Nature Communications, 2016; 7: 12113 DOI: 10.1038/ncomms12113 http://www.nature.com/articles/ncomms12113 Yours, Paul H.