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The Late Carboniferous a Time of Great Coal Swamps, Paleomap project. World map from this time period. The Carboniferous – 354 to 290 Million Years Ago, University of California Museum of Paleontology. Information on stratigraphies, localities, tectonics, and life. The Pennsylvanian Epoch of the Carboniferous Period: 318 to 299 Mya, Paleos.com
The geologic time scale is a way of representing deep time based on events that have occurred throughout Earth's history, a time span of about 4.54 ± 0.05 Ga (4.54 billion years). [3] It chronologically organises strata, and subsequently time, by observing fundamental changes in stratigraphy that correspond to major geological or ...
The Geology of Pennsylvania consists of six distinct physiographic provinces, three of which are subdivided into different sections. Each province has its own economic advantages and geologic hazards and plays an important role in shaping everyday life in the state.
The latest version of the geologic time scale was published in 2004, [6] and includes a comparison of present and past time scales. The greater efforts of geochronometry today are aimed at retrieving accurate ages of major events in the Earth's history and of stage / age boundaries.
Because defining a GSSP depends on finding well-preserved geologic sections and identifying key events, this task becomes more difficult as one goes farther back in time. Before 630 million years ago, boundaries on the geologic timescale are defined simply by reference to fixed dates, known as "Global Standard Stratigraphic Ages" (GSSAs).
This is a list of Global Boundary Stratotype Sections and Points.Since 1977, Global Boundary Stratotype Sections and Points (abbreviated GSSPs) are internationally agreed upon reference points on stratigraphic sections of rock which define the lower boundaries of stages on the geologic time scale.
Some of Pennsylvania's most important fossil finds were made in the state's Devonian rocks. [2] Carboniferous Pennsylvania was a swampy environment covered by a wide variety of plants. The latter half of the period was called the Pennsylvanian in honor of the state's rich contemporary rock record. By the end of the Paleozoic the state was no ...
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale.It spans the time between 251.9 Ma and 246.7 Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a unit in chronostratigraphy.