In the sedimentary rock cycle, or the process in which sedimentary rock forms, there are four steps: erosion, deposition, compaction, and cementation. The cementation rock cycle is an important ...Glacial Concretion 10 “Warm Love” $ 39.00 Add to cart; Glacial Concretion 11 “Complete Surrender” $ 59.00 Add to cart; Glacial Concretion 12 “Happy” $ 29.00 Add to cart; Glacial Concretion 13 “Make Your Mark” $ 29.00 Add to cart; Glacial Concretion 14 “Satisfied” $ 39.00 Add to cart; Glacial Concretion 15 “All Stirred Up ... concretion: A mass of mineral matter, often rounded, found in sedimentary rock It is harder than its surrounding rock; concretion: A hard round, oval, or other ...The occurrence of pyrite concretions in the Permian Longtan Formation sheds light on the paragenesis, formation conditions and regional paleoenvironment. We analyzed the mineral and geochemical characteristics of pyrite concretions using scanning electron microscopy-energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD) and laser ablation inductively coupled plasma mass spectrometry ...This article will dive deeper into the many great rockhounding sites across the state (along with maps), but I’d like to highlight a few standouts here. Here are 10 of the best rockhounding sites for rocks and minerals in South Dakota: Fairburn – Agates, Jasper, Agatized wood. Hell Canyon – Agate, Jade, Jasper, Geodes.A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word 'concretion' is derived from…. Concretions: The Other Valuable Mineral. As round as a bowling ball and just as heavy, a concretion is "the other valuable mineral" found in the Yukon. Unlike its more famous and sexier cousin, gold, a Yukon concretion tends to be bigger and more plentiful than most others found in the world. Yet it shares the same mystery and intrigue. Imagine night walking on a Lake Superior beach with a flashlight and seeing rocks that glow in the dark. Thanks to Michigan’s Erik Rintamaki who discovered them in 2017, those glowing rocks now have a name, Yooperlites. The grandson of Finnish immigrants, Rintamaki has been a long-time agate hunter on the beaches of Lake …Thus, at the late stage of concretion development, the Mn supply is largely exhausted and their surface showed a higher Fe and lower Mn concentration (Timofeeva et al., 2014). Fig. 5 presents the schematic model of Fe-Mn concretions and nodules formation based on White and Dixon (1996) work.Chert is a sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO 2 ). It occurs as nodules, concretionary masses, and as layered deposits. Chert breaks with a conchoidal fracture, often producing very sharp edges. Early people took advantage of how chert breaks and used it to fashion ...Septarian Meanings, Zodiacs, Planets, Elements, Colors, Chakras, and more. Science & Origin of SeptarianSeptarian Nodule, also referred to as @Dragon Stone@, is a tri color concretion composed of @Aragonite@ (the brown), Calcite, (the yellow), and Limestone (the grey). The name comes from the word “Septaria”, which usually refers to any …London Hammer. The London Hammer (also known as the "London Artifact") is a name given to a hammer made of iron and wood that was found in London, Texas in 1936. Part of the hammer is embedded in a limey rock concretion, leading to it being regarded by some as an anomalous artifact, asking how a man-made tool could come to be encased in Lower ...London Hammer. The London Hammer (also known as the "London Artifact") is a name given to a hammer made of iron and wood that was found in London, Texas in 1936. Part of the hammer is embedded in a limey rock concretion, leading to it being regarded by some as an anomalous artifact, asking how a man-made tool could come to be encased in Lower ... concretion, mass or nodule of mineral matter, usually oval or nearly spherical in shape, and occurring in sedimentary rock [1]. It is formed by the accumulation of mineral matter in the pore spaces of the sediment, usually around a fossil or fossil fragment acting as a nucleus.Once the overlying rock layers were eroded and the Navajo Sandstone revealed, weathering of the sandstone exposed the hard, weather-resistant iron concretions, many of which are amassed in large groups on the surface. Many concretions are located in State Parks, National Parks and Monuments, and Native American reservations where …5 listed What are cannonball concretions? Jutting out from the landscape, these large, round stones don’t appear to properly fit into the badlands. The secret lies in the large butte located nearby.WOSU. A round concretion about two feet in diameter sits half-buried along the creek in Shale Hollow Park. Danielsen explained that some of the biggest concretions can be found here in the Ohio Shale. "We can find them anywhere from like centimeter size, really little, to like 9 feet," Danielsen said.Feb 19, 2021 · All silica concretions are very hard and are laterally elongated parallel to the fine layers of the calcareous sedimentary rocks (Figs. 1b-1,b-2, 2a). The bitumen core of each silica concretion is ... This is just one method by which nature produces rocks that resemble eggs. Sedimentary concretions are another common imposter. Concretions often form when some object acts as a "seed" for the deposition and cementation of sequential layers of sediment. On occasion, the matter that initiates the concretion, the "seed," can be a fossil.Core Scanning. Exploration drilling turns the unknown into the known. This “core” activity is perhaps one of the most valuable assets in the mineral exploration workflow. Core extracted during diamond drilling is typically described by skilled geologists and along with geotechnical characterization is subjected to additional geochemical and ...concretion: [noun] something concreted: such as. a hard usually inorganic mass (such as a bezoar or tophus) formed in a living body. a mass of mineral matter found generally in rock of a composition different from its own and produced by deposition from aqueous solution in the rock. Since being raised, archaeologists and conservators have painstakingly excavated 1,200 pounds of concretion—rock-hard silt and sand that accumulated on the 40-foot-long, sausage-shaped craft as ...Concretions are formed through the precipitation of minerals in sediment before it hardens. Essentially, they became mineralized before the rest of the surrounding rock. Concretions form early on in the sedimentary stone cycle if they’re present. Remember that a sedimentary stone is comprised of a mass of sediment, such as sand or clay, that ...London Hammer. The London Hammer (also known as the "London Artifact") is a name given to a hammer made of iron and wood that was found in London, Texas in 1936. Part of the hammer is embedded in a limey rock concretion, leading to it being regarded by some as an anomalous artifact, asking how a man-made tool could come to be encased in Lower ...2 Haz 2017 ... It gets my vote as a really weird rock. I've become used to the idea that concretions can lead to some strange rocks. Several years ago, for ...The father's stone was not for sale. It was the first time I heard the word "concretion" and I was hooked. It took us a few years of occassional trips to the creek to finally find a spot along the fifty mile creek where these concretions come out of the clay and pour into its waters. The concretion on the left is the one I bought that day. Anhui Conch Cement News: This is the News-site for the company Anhui Conch Cement on Markets Insider Indices Commodities Currencies Stocksconcretion develops. Through slow chemical changes, minerals such as iron are extracted from the forming mass, causing its remnants to cement together, building the concretion. Often, they are harder than the material in which they came from. The process of erosion is responsible for revealing the concretions in the sedimen-tary rock.Concretions in mine roofs. Definition and formation: Concretions are isolated, often oval-shaped rock masses. Concretions are commonly composed of limestone (calcium carbonate), but silica-rich concretions also occur. Limestone concretions are most common in dark gray and black shale. Concretions normally form through accretionary mineral ...Cannonball concretions, often referred to as “cannonball rocks,” are fascinating geological formations that have captured the imagination of scientists and nature enthusiasts alike.These spherical or near-spherical masses of sedimentary rock have piqued the curiosity of researchers for generations, and their study continues to yield …Concretions are also commonly known as “fairy stones”. They are a type of geological oddity that typically occurs in sedimentary rocks, such as shale, limestone and sandstone. There are various theories of how they are formed, but it is typically believed that they formed in layers around a nucleus. These particular concretions are thought ...Being a geologic structure and not a pure mineral in itself, thundereggs are formed when a variety of factors are present. To begin, a hollow in a rock must form. This occurs most often when gas bubbles form in rhyolite lava flows. As the lava cools, a hollow of gas is trapped in the rock. Over thousands of years, small fractures in the rock ...A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Septarian concretions are concretions containing angular cavities or cracks, called "septaria". The septaria are the calcite filled cracks at the centre of the rock ... London Hammer. The London Hammer (also known as the "London Artifact") is a name given to a hammer made of iron and wood that was found in London, Texas in 1936. Part of the hammer is embedded in a limey rock concretion, leading to it being regarded by some as an anomalous artifact, asking how a man-made tool could come to be encased in Lower ... 2 Haz 2017 ... It gets my vote as a really weird rock. I've become used to the idea that concretions can lead to some strange rocks. Several years ago, for ...Apr 7, 2023 · A concretion is a hard mass found within layers of sedimentary stone. They’re generally round in shape, and each type tends towards one form or another. You shouldn’t confuse a concretion with a nodule. Jan 16, 2020 · Composition Concretions usually contain carbonate minerals such as calcite or iron oxide. However, others are composed of minerals like marcasite, dolomite, siderite, ankerite, pyrite, gypsum, and barite. A concretion contains one dominant mineral and several other minerals depending on the environmental conditions in which they are formed. Septarian nodules formed as a result of volcanic eruptions and compressed matter of Dead Sea creatures. Therefore, the bonds of Septarian nodules are formed in sediment through the “concretion” of mud masses and mixed organic material. Septarian nodules originate from the Cretaceous period and formed anywhere between 50 to 70 million years ago!In the Imperial Valley on the Mexican border, a site west of Calexico near the iconic mountain El Centinela (Mount Signal) yielded "sand spikes," concretions the shape of a whole clove. Most of them had their long tips pointed west. In 2000, they inspired artist Allan McCollum to make them the basis of a large art project, " Sand Spikes from ...Concretions in mine roofs. Definition and formation: Concretions are isolated, often oval-shaped rock masses. Concretions are commonly composed of limestone (calcium carbonate), but silica-rich concretions also occur. Limestone concretions are most common in dark gray and black shale. Concretions normally form through accretionary mineral ...Sedimentary rocks may be unconsolidated or consolidated, and the transformation from the former to the latter is known as diagenesis, a process during which further minerals form. ... Common concretion-forming minerals found in Wales include siderite (‘ironstone’), calcite, quartz, pyrite, apatite and the rare-earth phosphate, monazite.Septarian nodules formed as a result of volcanic eruptions and compressed matter of Dead Sea creatures. Therefore, the bonds of Septarian nodules are formed in sediment through the “concretion” of mud masses and mixed organic material. Septarian nodules originate from the Cretaceous period and formed anywhere between 50 to 70 million years ago!Being a geologic structure and not a pure mineral in itself, thundereggs are formed when a variety of factors are present. To begin, a hollow in a rock must form. This occurs most often when gas bubbles form in rhyolite lava flows. As the lava cools, a hollow of gas is trapped in the rock. Over thousands of years, small fractures in the rock ...Concretion rock tail morphologies include raised ridges that taper in height and width away from concretions, as well as pedestals supporting concretions at their tips. Rock tails do not occur in ...Hardie Board refers to James Hardie siding products produced by manufacturer James Hardie. The company has a selection of products that includes HardieTrim Boards and HardieTrim Cement Boards. There are also other cement board manufacturers...nodule, rounded mineral concretion that is distinct from, and may be separated from, the formation in which it occurs. Nodules commonly are elongate with a knobby irregular surface; they usually are oriented parallel to the bedding. Chert and flint often occur as dense and structureless nodules of nearly pure silica in limestone or chalk, where ...Oct 2, 2017 · A concretion split in half at “Devils Marbles” in Australia. Public Domain. Mysterious rock balls have unsurprisingly inspired more than one alien conspiracy theory over the years as well. Lewis Shale - Gray marine shale containing many gray and brown lenticular concretion-rich sandstone beds. Wasatch Formation - Diamictite and ... (North Wyoming) - Dull-red quartzitic sandstone. Cambrian Rocks (South Wyoming) - On south flank of Granite Mountains, blue-gray and yellow mottled hard dense limestone interbedded with soft …Calcite (calcium carbonate) is the most common cement for sandstone, but the bonding agent for concretions is a much more durable iron compound. As iron carbonate dissolves in groundwater, it precipitates around a fragment in the rock, such as a leaf, shell, bone, or fossil. The iron compound grows around this nucleus and a concretion begins.A chemical sedimentary rock, typically thin-bedded and/or finely laminated, containing at least 15% iron of sedimentary origin, and commonly but not necessarily containing layers of chert. Various primary facies (usually not weathered) of iron formation are distinguished on the basis of whether the iron occurs predominantly as oxide, silicate ...A concretion is a compact mass of mineral matter, usually spherical or disk-shaped, embedded in a host rock of a different composition. This hard, round mass of sedimentary rock cement is carried into place by ground water. A concretion is a compact mass of mineral matter, usually spherical or disk-shaped, embedded in a host rock of a different composition. This hard, round mass of sedimentary rock cement is carried into place by ground water. They usually form early in the burial history of sediment, before the rest of the sediment has hardened into solid rock.A concretion is a hard mass that forms when rock minerals precipitate in cracks or cavities, or through the build-up of sediment. These mineral masses are common in types of sedimentary rock, such …This is just one method by which nature produces rocks that resemble eggs. Sedimentary concretions are another common imposter. Concretions often form when some object acts as a “seed” for the deposition and cementation of sequential layers of sediment. On occasion, the matter that initiates the concretion, the “seed,” can be a fossil.WOSU. A round concretion about two feet in diameter sits half-buried along the creek in Shale Hollow Park. Danielsen explained that some of the biggest concretions can be found here in the Ohio Shale. "We can find them anywhere from like centimeter size, really little, to like 9 feet," Danielsen said.Also, hematite concretions are denser (heavier for their size) than any kind of stony meteorite or most other kinds of Earth rocks. For example, the specific gravity of an ordinary chondrite (the most common kind of meteorite) is about 3.9 whereas the specific gravity of a hematite concretion is 4-5. Magnetite (often blackish) has similar a ...Jan 16, 2023 · Paleoenvironmental information is better preserved in carbonate concretions. In this study, carbonate concretions in the Cretaceous Nenjiang shale, Songliao Basin, were examined to determine whether molecular fossils reflective of the paleoenvironment were better preserved at these sites. Organic and inorganic geochemical characteristics of the concretions and surrounding rocks were analyzed ... Within these deposits are yellow-brown ironstone concretions of various sizes. Paint pot concretions are produced by physical and chemical changes caused by the weathering of pyrite nodules in the ...Thus, at the late stage of concretion development, the Mn supply is largely exhausted and their surface showed a higher Fe and lower Mn concentration (Timofeeva et al., 2014). Fig. 5 presents the schematic model of Fe-Mn concretions and nodules formation based on White and Dixon (1996) work.The siderite concretion undergoes oxidative dissolution, which is possibly microbially mediated and which provides an internal source of Fe that forms an Fe-oxide crust on the outside the concretion. However, a problem with this model is that no siderite concretions have been identified, neither in outcrop ( 6 , 8 , 9 ) nor in any deeper ...A comprehensive study is presented of the characteristics of calcareous concretions in the Connecticut Valley varved clay (CVVC), a glacial lake sediment, probed by an array of investigations, including compositional analyses via X-ray powder diffraction and energy-dispersive X-ray spectroscopy, mechanical property mapping by nanoindentation, selective dissolution, microstructure examination ...Significance: These unusual stone formations are a fascinating look into the geological processes of the North Dakota badlands. Amenities. 5 listed. What are cannonball concretions? Jutting out from the landscape, these large, round stones don't appear to properly fit into the badlands. The secret lies in the large butte located nearby.Once relegated to the driveway or exterior walls, concrete is gaining popularity all over the house, from the front steps to the bathtub. It’s durable, easy to maintain and looks as cool as it feels to the touch. Concrete is also versatile.Signs of concretions. Small white/yellow-white bodies with distinct edges in tarsal (upper or lower) conjunctiva. Single or multiple. May stain with fluorescein. Usually <1mm diam, sometimes up to 3mm. appear larger if confluent. Usually low profile but may be …Other articles where concretion is discussed: sedimentary rock: Bedding structure: Local cementation may result in concretions of calcite, pyrite, barite, and other minerals. These can range from sand crystals or barite roses to spheroidal or discoidal concretions tens of metres across.Beach, sand dunes (desert or beach); river banks. Source rock probably far away. < 2 mm >25% potassium feldspar grains, with quartz Arkose Beach sands; river deposits. Source rock most likely feldspar-rich granite. > 1/16 mm Mixed mineral grains/rock fragments. Beach sands; river deposits. Source rock probably nearby. Mud < 1/16 mmSand Concretion Rock Beach Nature’s Sculpture Fairy Stone Lot of 3. Image Credit: Valuable Beach Stones. You might find an intricate piece of coral and mistake it for a beach stone. But sometimes, nature’s tumbling action can create rock sculptures that rival the most hyperactive polyps. This set of three is a good example, with all its ...Concretion. Concretions are masses of mineral matter embedded within rock layers, including limestone, sandstone, and shale. They often take shape when minerals precipitating (settling) out of water collect around a nucleus, such as a pebble, leaf, shell, bone, or fossil. Concretions most often form in sediment before or as the sediment is ... 1.. IntroductionThe term “concretion” means local concentrations of authigenic mineral species that show contrast with the surrounding host rocks (Selles-Martinez, 1996).Calcite-cemented concretions in clastic rocks show a wide variety of shapes, sizes and geometries (Bjorkum and Walderhaug, 1990, McBride et al., 1995, …Septarian Concretion. A concretion is a mass of mineral matter embedded within rock layers, including shale, limestone, and sandstone. They take shape when minerals settling out of water collect around a nucleus, like a leaf, pebble, bone, shell, or fossil. Concretions are generally harder than the rocks surrounding them.It does not matter whether you choose the bus, the train or the bicycle, Concretion Post-rock Festival is easy to reach! Aquileia is close to the airport, the highway and also the railway. the event area is located on the path of a cycle path over 400 km long, connecting salzburg to the adriatic sea. You can get there easily by all means of ...The father's stone was not for sale. It was the first time I heard the word "concretion" and I was hooked. It took us a few years of occassional trips to the creek to finally find a spot along the fifty mile creek where these concretions come out of the clay and pour into its waters. The concretion on the left is the one I bought that day.Concretions are roughly spherical rocks – think Moeraki Boulders – which often contain fossils. Fossils are formed when organic matter – such as wood or bone – is buried by small particles ...The A-CN-K and A-CNK-FM ternary diagrams drawn for concretion and host rock bulk composition clearly indicate the interaction of concretions rock with iron-bearing diagenetic fluids. A negative Ce anomaly, lower Th/U ratio, and enrichment of redox responsive trace element (e.g., vanadium) indicate concretion formation is redox-controlled.3 Nis 2013 ... Am I correct in my understanding that concretions are just rocks that are composed of sediment similar to where they are extracted from or ...As a contractor, accuracy is everything when it comes to estimating concrete projects. One tool that can significantly improve the precision and efficiency of your estimates is a concrete estimate calculator.1.. IntroductionThe term “concretion” means local concentrations of authigenic mineral species that show contrast with the surrounding host rocks (Selles-Martinez, 1996).Calcite-cemented concretions in clastic rocks show a wide variety of shapes, sizes and geometries (Bjorkum and Walderhaug, 1990, McBride et al., 1995, …Concretions are hard bodies that form in sediments before they become sedimentary rocks. Slow chemical changes, perhaps related to microbial activity, cause minerals to come out of the groundwater and seal the sediment together. Most often the cementing mineral is calcite, but the brown, iron-bearing carbonate mineral siderite is also common.London Hammer. The London Hammer (also known as the "London Artifact") is a name given to a hammer made of iron and wood that was found in London, Texas in 1936. Part of the hammer is embedded in a limey rock concretion, leading to it being regarded by some as an anomalous artifact, asking how a man-made tool could come to be encased in Lower ...Scientists and fossil experts concluded the rock is a concretion a stack of sedimentary rock made up of a mineral cement deposited by groundwater that flows through pores between the grains of ...A concretion is a hard, compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes also occur. The word 'concretion' is derived from the Latin concretio " compacting, condensing, congealing, uniting", itself from con meaning 'together' and ...The best way to check for these is through the Yellow Pages, either in the book or online. You can also check with your Chamber of Commerce to see if they have suggestions. Sometimes bead stores or even jewelry stores might have some people knowledgeable about rocks or minerals. Find a small family owned store.A rock or concretion, like the one I showed to my professor, will be solid, and the inside of the rock will look like the outside. Fossil bone, on the other hand, will probably preserve the ...Minnesota is known for its agates, predominantly found in the Lake Superior region or Moose Lake; however, you can also find geodes, gold, fossils, amethyst, yooperlites, and much more sedimentary igneous and metamorphic rocks. The most famous gravel pits are the Hatchery Pit, the Soo Line Pit, and the Airport Pit.Trovants are spherical and slightly irregular-shaped rocks. They can be as small as less than an inch, or a couple of millimeters, in diameter and weigh only a few grams, or they can soar up to 15 feet (4.5 meters) high and weigh several tons. These odd, gravity-defying boulders have baffled observers since the 18th century with many a curious ... Much of the terrestrial concretion mineralogy can be distinguished by traditional laboratory methods (Table 1) of petrography, X-ray diffraction, whole rock analysis, spectroscopy, and electron microscopy. Highly detailed analyses of trace element geochemistry, isotopes, and tomography (discussed below) can provide additional insight.Comité Région SUD Provence-Alpes-Côte d'Azur FFC, Marseille. 1,939 likes · 137 talking about this. Comité Région SUD Provence Alpes Côte d'Azur FFC Siège...
Kansas Pop Rocks. Curious iron sulfide concretions found in Gove County, Kansas. These are formed of pyrite or marcasite, creating a roughly spherical concretion. They're called pop rocks because they have a tendency to explode when thrown in a fire. When struck, the iron sulfide generally sparks as well.. Taste of lawrence
Also, hematite concretions are denser (heavier for their size) than any kind of stony meteorite or most other kinds of Earth rocks. For example, the specific gravity of an ordinary chondrite (the most common kind of meteorite) is about 3.9 whereas the specific gravity of a hematite concretion is 4-5. Magnetite (often blackish) has similar a ... Rocks that grow to be as big as a person? Landscapes of giant rocks that look like outer space? OMG…this is the most totally cool thing EVER! I was hooked and absolutely, positively needed to find these things and see them for myself. Thus began a 2-week expedition of “concretion hunting” with some fun exploration and exciting pictures to ...Aug 30, 2022 · A concretion is a compact mass of mineral matter, usually spherical or disk-shaped, embedded in a host rock of a different composition. This hard, round mass of sedimentary rock cement is carried into place by ground water. They usually form early in the burial history of sediment, before the rest of the sediment has hardened into solid rock. In order to see the fossil, you need to break open the con- cretion. There are a couple of ways to do this. Some people use a rock hammer to open concretions.Other articles where concretion is discussed: sedimentary rock: Bedding structure: Local cementation may result in concretions of calcite, pyrite, barite, and other minerals. These can range from sand crystals or barite roses to spheroidal or discoidal concretions tens of metres across.Concretion rock in Theodore Roosevelt National Park, North Dakota, USA . (M. Readey/ CC BY SA 3.0 ) Giant Concretions . It is not entirely clear how giant concretions form compared to more typical smaller concretions, though it is known that they tend to form deep beneath the ground.Cannonball concretions, often referred to as “cannonball rocks,” are fascinating geological formations that have captured the imagination of scientists and nature enthusiasts alike.These spherical or near-spherical masses of sedimentary rock have piqued the curiosity of researchers for generations, and their study continues to yield …Once the overlying rock layers were eroded and the Navajo Sandstone revealed, weathering of the sandstone exposed the hard, weather-resistant iron concretions, many of which are amassed in large groups on the surface. Many concretions are located in State Parks, National Parks and Monuments, and Native American reservations where …Concretion. Reefs are rocky substrates and biogenic concretions, which arise from the sea floor in the sublittoral zone: they may extend into the littoral zone, where there is an uninterrupted zonation of plant and animal communities. From: Elsevier Oceanography Series, 2004. Add to Mendeley.Use this printable infographic to learn about the rock cycle. There are three main types of rocks: sedimentary, igneous, and metamorphic. Each of these rocks are formed by physical changes—such as melting, cooling, eroding, compacting, or deforming —that are part of the rock cycle. Sedimentary rocks are formed from pieces of other existing ...2 Haz 2017 ... It gets my vote as a really weird rock. I've become used to the idea that concretions can lead to some strange rocks. Several years ago, for ...London Hammer. The London Hammer (also known as the "London Artifact") is a name given to a hammer made of iron and wood that was found in London, Texas in 1936. Part of the hammer is embedded in a limey rock concretion, leading to it being regarded by some as an anomalous artifact, asking how a man-made tool could come to be encased in Lower ... A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular shapes also occur.A concretion is a compact mass of mineral matter, usually spherical or disk-shaped, embedded in a host rock of a different composition. This hard, round mass of sedimentary rock cement is carried into place by ground water. Concretions, the most varied-shaped rocks of the sedimentary world, occur when a considerable amount of cementing material ...The geologist studied the concretion patterns in the rock formations. Concretion can also be used in a more figurative sense to describe the process of forming a cohesive whole from disparate parts. For example: The team’s success was due to the concretion of individual talents and efforts.A chemical sedimentary rock, typically thin-bedded and/or finely laminated, containing at least 15% iron of sedimentary origin, and commonly but not necessarily containing layers of chert. Various primary facies (usually not weathered) of iron formation are distinguished on the basis of whether the iron occurs predominantly as oxide, silicate ....