Search results
Results From The WOW.Com Content Network
Regardless of the mechanism of crack formation, the septaria, like the concretion itself, likely form at a relatively shallow depth of burial of less than 50 meters (160 ft) [51] and possibly as little as 12 meters (39 ft). Geologically young concretions of the Errol Beds of Scotland show texture consistent with formation from flocculated ...
The concretions occur in localized deposits within the silty to sandy mudstones, in the lower four metres of the formation. The paleoecosystem was once believed to be a large river delta system, deposited by at least one major river system flowing from the northeast, but it has been reinterpreted as a bay into which some rivers brought some ...
Similar to the marine nodules, concretion layers are defined based on iron and manganese content as well as their combination. [2] High iron content nodules appear a red or brown color, while high manganese content appears black or grey. [2] The dominant metal oxide is related to the elements enriched in the nodule.
The Pierre Shale is the host formation for commercial petroleum deposits in the Florence and Canon City fields in Fremont County, Colorado, and the Boulder Oil Field in Boulder County, Colorado. More recently, natural gas has been extracted in the Raton Basin in southern Colorado .
Devonian nodular limestone Concretionary nodular limestone at Jinshitan Coastal National Geopark, Dalian, China. In geology and particularly in sedimentology, a nodule is a small, irregularly rounded knot, mass, or lump of a mineral or mineral aggregate that typically has a contrasting composition from the enclosing sediment or sedimentary rock.
Cone-in-cone structures have been known since the late 1700s, and people have attempted to explain the reasons for their formations. One of the earlier explanations was actually on par with the currently accepted methods for formation as discussed above. Some of the other methods offered for their formation were given by Shaub (1937). [9]
A coal ball is a type of concretion, varying in shape from an imperfect sphere to a flat-lying, irregular slab.Coal balls were formed in Carboniferous Period swamps and mires, when peat was prevented from being turned into coal by the high amount of calcite surrounding the peat; the calcite caused it to be turned into stone instead.
An enterolith is a mineral concretion or calculus formed anywhere in the gastrointestinal system. Enteroliths are uncommon and usually incidental findings but, once found, they require at a minimum watchful waiting. If there is evidence of complications, they must be removed.