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Bluedating review

This was not adopted, but his division into Mississippian, for the 's "Story of a piece of coal" focuses on coal formation, but includes a section on the carboniferous limestone.It lists (but does not discuss) the intervening millstone grit.

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Mesoproterozoic from 1,600,000,000 to 1,000,000,000 years ago. Particular importance attaches to occurred around 1,300,000,000 years ago during the late Mesoproterzoic era, after the earth's transition to a more highly oxygenated atmosphere with an ozone screen. Deposits that made Westmorland Green slate formed around 450 million years ago. About 50 million years later, the material was altered by heat and pressure (metamorphosed) to slate, during mountain-building. After many more millions of years, they resembled patches of moss a few centimeters high.By carboniferous [carbon bearing] soils, Richard Kirwan in 1799 meant the "various sorts of earth or stone among or under which coal is usually found".William Daniel Conybeare and William Phillips (1822, page vii) proposed to consider all rocks in an ascending order with a group including "not only the great coal-deposit itself, but those of the limestone and sandstone also on which it reposes" as the "medial" [middle] order.Galena can contain minor amounts of antimony, arsenic, bismuth, cadmium, copper, silver, and zinc See and stalagmites.Encountering impermeable strata (such as toadstone) it forms underground lakes in the limestone which overflow to the surface as natural springs (a resurgence).All plants were responsible for the transformation, but Archaeopteris was important because it made up 90 percent of the forests during the last 15 million years when these changes accelerated" ...

"It was the first plant to produce an extensive root system, so had a profound impact on soil chemistry".

It mentions the following periods to indicate how long ago coal was formed: Carboniferous followed by 359,200,000 - 326,400,000 years ago Dinantian series or epoch from the Lower Carboniferous system in Europe 326,400,000 to 313,400,000 years ago Namurian stage in the regional stratigraphy of northwest Europe are found - Silicious Grit, providing stone for building and millstones - Shale - then lime-stone and toadstone alternately.

The veins of metallic ores appeared in the limestone.

writes of fine-grained greenish sandstones deposited in freshwater in which land plant fossils are well preserved.

"Among the most attractive of these" tree-fern once called Cyelopteris (Round-leaved Fern), re named Palasopteris Hibernicus (Primitive Irish Fern). It was the "monarch of the primeval forests" whose "graceful fronds bent over the clear waters of a lake".

It is suggested that analysis of sedimentary pyrite from the Belingwe sedimentary basin in Zimbabwe may provide evidence for bacterial reduction at this date.