Title: Coal measures
Content: Permian or later in age. In some parts of Britain, however, the Coal Measures grade up into mainly coal-barren red beds of late Westphalian and possibly Stephanian age. Within the Pennine Basin these barren measures are now referred to as the Warwickshire Group, from the district where they achieve their thickest development. The coal measures formed during Westphalian and earliest Stephanian times in the European ('Heerlen') chronostratigraphical scheme (which is approximately equivalent to the Middle Pennsylvanian Series of the IUGS global chronostratigraphical scheme). In the eastern United States the term coal measures has been applied to the Pennsylvanian coal fields.

Title: Geological period
Content: example the 'Jurassic System' of rocks was formed during the 'Jurassic Period' (between 201 and 145 million years ago). The following table includes all currently recognized periods. The table omits the time before 2500 million years ago, which is not divided into periods. See Geologic time scale#Proposed Precambrian timeline for another set of periods 4600–541 MYA. In a steady effort ongoing since 1974, the International Commission on Stratigraphy has been working to correlate the world's local stratigraphic record into one uniform planet-wide benchmarked system. American geologists have long considered the Mississippian and Pennsylvanian to be periods in their own right

Title: History of the Ruhr
Content: Carboniferous Period, in the Paleozoic era, which began 360 million years ago and ended 300 million years ago, layers of slate, coal and sandstone were formed. 400 to 300 million years ago, new mountains were uplifted during the Variscan mountain-building period. During the Silesian period, layers were deposited which became seams of coal over a period lasting millions of years. During this period there was a constant shifting between marshy conditions and overflowing seas such that the depositing of plant material and sediment from the sea resulted in the current situation of coal layers separated by stone layers. The main

Title: Geologic time scale
Content: scale that included absolute dates was published in 1913 by the British geologist Arthur Holmes. He greatly furthered the newly created discipline of geochronology and published the world-renowned book "The Age of the Earth" in which he estimated Earth's age to be at least 1.6 billion years. In 1977, the "Global Commission on Stratigraphy" (now the International Commission on Stratigraphy) began to define global references known as GSSP (Global Boundary Stratotype Sections and Points) for geologic periods and faunal stages. The commission's most recent work is described in the 2004 geologic time scale of Gradstein et al. A UML model

Title: Geologic time scale
Content: subdivision is formally recognized, and lower case when not; thus "early Miocene" but "Early Jurassic." Evidence from radiometric dating indicates that Earth is about 4.54 billion years old. The geology or "deep time" of Earth's past has been organized into various units according to events which took place. Different spans of time on the GTS are usually marked by corresponding changes in the composition of strata which indicate major geological or paleontological events, such as mass extinctions. For example, the boundary between the Cretaceous period and the Paleogene period is defined by the Cretaceous–Paleogene extinction event, which marked the demise

Question: What is the name given to the geological time period of 363-290 million years ago during which coal measures were formed?
Answer: Carboniferous