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I’ll show my collection here. 1. Agnostida This is my only example from this order. Itagnostus interstrictus Wheeler Shale U-dig Quarry, Delta, Millard County, Utah Middle Cambrian Purchased Scale bar is 1 cm.

Most people are familiar with the Conasauga Formation when they think of Georgia's Cambrian record, but the Peach State has a paleontological history dating back several million years before the Conasauga was deposited. Indeed, the oldest fossils in Georgia date back to the early Cambrian, and consist of a diverse form of worms, brachiopods, trilobites, and other creatures such as hyoliths and archaeocyathids. This early Cambrian record is largely divided into three formations, from oldest to youngest the Weisner Formation (part of the Chilhowee Group), the Shady Dolomite, and the Rome Formation. All of these formations, as well as the overlying middle Cambrian rocks of the Conasauga Formation, are well exposed in the Rome and Cartersville areas. Cartersville is a mid-sized town in North Georgia with a rich interconnection between history and geology. Situated near the confluence of three major geological provinces (the Valley and Ridge, the Blue Ridge, and the Piedmont), the Cartersville area was uniquely positioned for the discovery and future development of a variety of mineral resources. Wide scale mining began in the mid-19th century with the establishment of the Etowah Iron Works along the Etowah River. Although the bulk of the works were destroyed by Union forces during the Civil War, mining not only continued in and around Cartersville but actually expanded in the post-war period. Iron was the principal product for a while owing to the region's rich limonite deposits, but by the turn of the century ochre and barite production also became prominent, if not more so. Mining operations peaked by the middle of the 20th century, but some active mines remain in the area, and they continue to be a favorite with mineral and fossil collectors. Thankfully, this past history of mining, combined with the recent construction due to Atlanta's explosive growth, has exposed rocks typically left buried under the thick clay and vegetation of North Georgia. The Shady Dolomite was, and still is, the focus of the brunt of the ochre mining around Cartersville. A carbonate unit, the Shady is easily weathered in North Georgia's humid and rainy climate, dissolving much of the rock and underlaying the ground in a thick, reddish clay. Due to the nature of the weathering, however, distinct beds can sometimes be seen in cuts made into the Shady, as shown in the above photo from a construction site in Cartersville. Another exposure of the red clay residuum made out of weathered material from the Shady Dolomite. Although the carbonates of the Shady are frequently weathered into a thick, red muck, this weathering process typically uncovers a wide variety of rock types that are more resistant to chemical attack, and which would have otherwise been locked into the dolomite. At exposures like the one above, pieces of shale, iron oxides, and chert are common. Alongside the chert are fossils from some of the oldest reef communities in Georgia. This small piece of rock contains fragments of archaeocyathids, ancient sponge-like organisms that once established reefs in the early Cambrian sea. Alongside archaeocyathids, other fossils like trilobites and brachiopods are sometimes found in the Shady, but I didn't find any personally. Aside from iron and ochre, Cartersville was an important center for barite mining around the turn of the century. Most barite mines were located east of town, near the contact between the Valley and Ridge and the Blue Ridge provinces. Although most have been filled in or flooded, one pit that is still left can be seen at Pine Mountain east of town. A few pieces of barite ore line the trail leading up the mountain. A small piece of barite ore from near Cartersville. The walls of a former mining operation near the base of Pine Mountain contrasted with an image of a similar mine when in operation. Leading up the trail at Pine Mountain, one travels across geologic provinces. The valley floor is underlain by rocks of the Shady Dolomite and Rome Formation, part of the Valley and Ridge province, while Pine Mountain itself lies within the Blue Ridge. Climbing up Pine Mountain, you begin to sense that change reflected in the rocks underneath you. The red clay and chert residuum of the Valley and Ridge gives way to brown and white dirt, and the chert and dolomite boulders give way for quartzose sandstones, quartzites, and schists. Along the trail, numerous pieces of quartz sandstone from the Weisner Formation are exposed, and in these boulders you can sometimes catch glimpses of the earliest recorded life in Georgia! The picture here shows a sandstone boulder with a couple of well-worn Skolithos linearis worm burrows. Whereas the Shady Dolomite was deposited in a shallow, tropical sea, the upper Chilhowee Group was deposited in a near-shore environment as indicated by the coarse sediment. That means that 530-550 million years ago, during the early Cambrian, what is now a mountain would have been a warm, sandy beach! And, although they may not seem like much, the humble tubes in the rock illustrate a time when life was not everywhere abundant, and the diverse lifeforms we find at beaches today had yet to appear. Climbing the rocky trail to the summit, one is well-rewarded with a view of the entire Cartersville area, including a view across much of the Piedmont to Kennesaw Mountain beyond, and across much of the Great Valley to the Armuchee Ridges. One can also get a sense of the legacy of intense mining that took place around Cartersville from the many red-colored pits scoured into the nearby hillsides, ghosts of operations past and present. On top of all of that, one can also visualize the impact geology has on the topography of an area. Being the intersection of so many geologic provinces, the Cartersville area is marked by numerous faults, folds, and other complex structural geology that has left pockets of one formation nearly surrounded by pockets of another. This has contributed to the hilly nature around Cartersville, as the comparatively resistant rocks of the Rome Formation and Chilhowee Group forms island-hills in the sea-valleys of the Shady Dolomite. The view from Pine Mountain. The red areas are current and past mines around Emerson, Georgia, just south of Cartersville (which includes the buildings in white). The hills here, which make up part of the Allatoona Mountains, are held up by resistant units like the Chilhowee and Rome while the valleys are underlain by softer carbonates like the Shady. On a clearer day you could make out the Armuchee Ridges lying at the western edge of the Great Valley, a synclinorium of Cambro-Ordovician rocks that stretches from here all of the way to Quebec. I hope you enjoyed the report!

Hello, I need contact information of a palaeoartist from Ontario: unfortunately I have no twitter account, so if anyone could help me and send me his E-mail/contact information via PM (or somebody who knows him and can send him mine?) Best Regards Johannes Unfirt

This summer a friend brought me this rock from the town of Pomer (Zaragoza). The age of the rocks in the area is Cambrian and I think it could be some kind of arthropod, I don't know... It was found at an altitude of 1300m. Can someone help me?

Hello everyone, Here I have a peculiar trilobite specimen that I discovered cracking shale from the Wheeler Formation. It comes from the House Range in Millard County, Utah, and I know it's mid Cambrian. Thanks!

Got the itch to collect and study some stromatolites, so I did some searching and feel that I successfully scratched the itch. I found a section of the Cambrian Copper Ridge dolomite that exposes a plethora of stromatolites of various morphologies. Many of them look as if they are straight out of Shark Bay in Australia, with the characteristic domal structure attached to a thinner holdfast on a hard substrate. Stromatolites are formed over a long period of time in tidal zones by colonies of photosynthetic bacteria and/or algae that form sticky layers that trap sediments and concrete them into layers. The colony then grows over the older, cemented colony and the cycle repeats itself. The process is obviously a lot more complicated than that, but I digress. Stromatolites are the oldest confirmed fossils to have been discovered, with the current oldest ones to be confirmed coming from the Strelley Pool Chert formation in Western Australia, dating back to the early Archaen at approximately 3.4 billion years ago. At that point in time, the Earth's atmosphere was largely devoid of oxygen, primarily being composed of CO2. Over the next several billion years, these stromatolites were largely responsible for oxygenating the atmosphere. They may not look like much, but these bacterial colonies were extremely important to creating Earth's biosphere. After the Cambrian explosion, stromatolites began to become quite rare in the fossil record, with multicelluar organisms feeding on them and disrupting the cementation process. After that point and to this day, stromatolites primarily thrive in extreme environments were the animals that feed on them cannot survive. The stromatolites in the Shark Bay, Australia area live in a hypersaline environment created by a seagrass barrier just off the coast. Unfortunately climate-change induced increases in precipitation are causing floods that reduce the salinity of this location and threaten the survival of the stromatolite colonies. With that information, enjoy these photos of stromatolites. Cube scale is 2cm on each side Large domal type in the position it would have grown in: Another domal type, almost spherical in shape, composed of multiple separate colonies that appear to have fused together: Another domal type: Cross section of broken laminar piece showing growth layers over an oolitic limestone substrate: A different one, I hope to polish this face: Layers under microscope:

Frenchman Mountain Dolostone: 500 million-year-old Grand Canyon rock layer finally gets a name. UNLV geologists name ancient rock layer after Las Vegas mountain that contains similar strata; research published in the journal Geosphere. New Study Links Geologic Features of Las Vegas’ Frenchman Mountain with Grand Canyon. Las Vegas Valley rock layer matches that of a famous interval of rocks at the Grand Canyon; findings reported in the Journal Geology. University of Nevada at Las Vegas, May 1 , 2020 The open access paper is: Rowland, S.M., Korolev, S., Hagadorn, J.W. and Ghosh, K., 2023. Frenchman Mountain Dolostone: A new formation of the Cambrian Tonto Group, Grand Canyon and Basin and Range, USA. Geosphere. Supplemental Material: Frenchman Mountain Dolostone: A new formation of the Cambrian Tonto Group, Grand Canyon and Basin and Range, USA, Geological Society of America Another paper is: Karlstrom, K.E., Mohr, M.T., Schmitz, M.D., Sundberg, F.A., Rowland, S.M., Blakey, R., Foster, J.R., Crossey, L.J., Dehler, C.M. and Hagadorn, J.W., 2020. Redefining the Tonto Group of Grand Canyon and recalibrating the Cambrian time scale. Geology, 48(5), pp.425-430. Related papers: Rowland, S.M., 2022, Geology of Frenchman Mountain and Rainbow Gardens, southern Nevada, USA, in Jiang, G.Q., and Dehler, C., eds., Field Excursions from Las Vegas, Nevada: Guides to the 2022 GSA Cordilleran and Rocky Mountain Joint Section Meeting: Geological Society of America Field Guide 63, p. 23– 43. Rowland, S.M., 1987, Paleozoic stratigraphy of Frenchman Mountain, Clark County, Nevada, in Hill, M.L., ed., Cordilleran Section of the Geological Society of America: Geological Society of America Centennial Field Guide 1, p. 53– 56. Hollingsworth, J.S., Sundberg, F.A. and Foster, J.R., 2011. Cambrian stratigraphy and paleontology of Northern Arizona and Southern Nevada. Museum of Northern Arizona Bulletin, 67, pp.1-321. PDFs of more trilobite papers. Videos Wild Speaker Series: The Amazing Geology of Frenchman Mountain and Rainbow Gardens. Friends Of Nevada Wilderness Frenchman Mountain Loop | Bordering Lake Mead National Nevada Trilobites, Frenchman Mountain Yours, Paul H.

Hello! I bought these Cambrian soft tissue fossils supposedly from Yunnan in china off of online auction site. I won them in a bid for suspiciously cheap. They seem real to me, but I’d be interested in confirmation of that. I’m also interested what you guys have to say as to what these are. Thanks! One is listed as Naraoia spinosa, the other, fainter one is listed as Vetulicola.

After scouting some Kinzers spots with @Dean Ruocco , we found ourselves in rock with some beautiful Cambrian bugs. Not nearly all…but some highlights in order 1. Olenllous Getzi (Cephalon) 2. Olenllous Sp. (full bug) 3. Wanneria Walcottana (Thorax/pygdium)