Monday, February 21, 2011Reconstructing the History of Life Part III: "Absolute" Age Dating Wednesday, February 9, 2011Reconstructing The History Of Life Part II: Biostratigraphic Correlation Wednesday, February 2, 2011 Jeffrey Martz Poncha Springs CO USA This is a blog about paleontology (the study of the history of life on Earth through the fossil record) with an emphasis on vertebrate paleontology, the study of extinct vertebrates (animals with backbones).The methodology and findings of paleontology will be discussed, as well as related issues such as evolutionary theory.The real question is what happens when conditions are ideal, versus when they are marginal, because ideal samples should give the most reliable dates. A lineage zone is named for the taxon in the lineage whose range or partial range it represents. Within the Trenton Group, the key graptolite taxa used for dating are.In the case of the first study, shown in the diagram below, Mitchell and Bergst röm (1991) establish correlations between distant geographic localities using principles of biostratigraphic zonation.The biostratigraphic situation can be summarized as a vertically-stacked sequence of "zones" defined by the first appearance of each ammonite species: Figure.Charles Darwin explained the mechanism behind it - evolution.
In 1796 William Smith, a British civil engineer, addressed this, adding the principle of In 1815, Smith published the first geologic map of England.
In the last blog, I discussed the Law of Superposition.
Layers of sedimentary rocks, or strata, are stacked in vertical sequences, with the oldest layers being on the bottom, and getting younger as we go up through the layers.
Nannofossils are particularly good for biostratigraphy because they are abundant, planktonic, rapidly evolving and widely distributed.
Their small size means they can be studied from minute rock chips, which is of particular value in hydrocarbon exploration and development, and scientific drilling.
The blogger is a vertebrate paleontologist specializing in the Triassic Period, the Beginning of the Age of Dinosaurs.