Concretion - Wikipedia A concretion is a hard and compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil [1] Concretions are often ovoid or spherical in shape, although irregular shapes also occur
Concretions, Thunder Eggs and Geodes - The Australian Museum Concretions can have regular shapes like blocks, boxes, pipes, flat discs, canon balls, or even resemble parts of a human body such as a foot or rib It is sometimes hard to believe that they formed by natural processes Ironstone concretions are common around Sydney, with its outcrops of iron-rich shale and sandstone
Concretions Picture Gallery - ThoughtCo 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
What Is A Concretion? - WorldAtlas Often mistaken for bones, turtle shells, or fossil eggs, concretions are geological features found in sedimentary rock and soil A concretion is a hard mass that forms when rock minerals precipitate in cracks or cavities, or through the build-up of sediment
Concretions - Paleontological Research Institution Concretions are commonly misunderstood geologic structures Often mistaken for fossil eggs, turtle shells, or bones, they are actually not fossils at all but a common geologic phenomenon in almost all types of sedimentary rock, including sandstones, shales, siltstones, and limestones
Carbonate concretions—explained - Dorset Geologists Association In this article we explain how and where concretions form and discuss the evidence, ranging from outcrop data to sophisticated laboratory analyses, which can be used to determine their origins The roles of microbes, decaying carcasses, compaction and groundwaters are highlighted
Concretions - Natural Atlas 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
Concretions - DesertUSA 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