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Tree remains that have undergone petrifaction, as seen in Petrified Forest National Park. In geology, petrifaction or petrification (from Ancient Greek πέτρα (pétra) 'rock, stone') is the process by which organic material becomes a fossil through the replacement of the original material and the filling of the original pore spaces with minerals.
Rhizoliths are organosedimentary structures formed in soils or fossil soils by plant roots. They include root moulds, casts, and tubules, root petrifactions , and rhizocretions. Rhizoliths, and other distinctive modifications of carbonate soil texture by plant roots, are important for identifying paleosols in the post- Silurian geologic record.
Soil fossils are usually classified by USDA soil taxonomy.With the exception of some exceedingly old soils which have a clayey, grey-green horizon that is quite unlike any present soil and clearly formed in the absence of O 2, most fossil soils can be classified into one of the twelve orders recognised by this system.
The record of paleosols extends into the Precambrian in Earth's history, with rare paleosols older than 2.5 billion years. Geology, biology, and the atmosphere all changed significantly over that time, with dramatic shifts at the Great Oxidation Event (2.42 billion years ago) and during the Paleozoic, when complex animals and land plants proliferated.
A polystrate fossil is a fossil of a single organism (such as a tree trunk) that extends through more than one geological stratum. [1] The word polystrate is not a standard geological term. This term is typically found in creationist publications.
Layers of sediment do not extend indefinitely; rather, the limits can be recognized and are controlled by the amount and type of sediment available and the size and shape of the sedimentary basin. Sediment will continue to be transported to an area and it will eventually be deposited. However, the layer of that material will become thinner as ...
The fossil record and faunal succession form the basis of the science of biostratigraphy or determining the age of rocks based on embedded fossils. For the first 150 years of geology , biostratigraphy and superposition were the only means for determining the relative age of rocks.
Engraving from William Smith's monograph on identifying strata based on fossils. Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment.