Pemigewasset Wilderness - Geography - Geology


While most of the White Mountains consist of highly metamorphicized schists and gneisses formed during the Acadian Orogeny, the Pemigewasset Wilderness is part of the White Mountain Batholith and is therefore composed primarily of the igneous White Mountain plutonic-volcanic rock series.

The Franconia and Twin Ranges form a massive ring dike in the western half of the White Mountain Batholith made up of a granite porphyry backbone that emerged roughly 170 million years ago. This rock appears pink, red, green or grey, with medium-sized phenocrysts. Such phenocrysts, usually quartz or feldspar, make up 20%-40% of the rock, and are embedded in a groundmass of similar composition. Enclosed by the ring dike and extending in to the flat floor of the wilderness is a large area of biotite and amphibole granite.

Read more about this topic:  Pemigewasset Wilderness, Geography

Other articles related to "geology":

Regional Geology - By Planet
... Geology of Mars Geology of Mercury Geology of the Moon Geology of Venus ...
History Of Biology - 19th Century: The Emergence of Biological Disciplines - Natural History and Natural Philosophy - Geology and Paleontology
... See also History of geology and History of paleontology The emerging discipline of geology also brought natural history and natural philosophy closer together the ... Charles Lyell's influential Principles of Geology (1830) popularised Hutton's uniformitarianism, a theory that explained the geological past and present on equal terms ...
Sugar Land, Texas - Geography and Climate - Geology
... Underpinning the area's land surface are unconsolidated clays, clay shales, and poorly-cemented sands extending to depths of several miles ... The region's geology developed from stream deposits from the erosion of the Rocky Mountains ...
Basin And Range Province - Geology
... The average crustal thickness of the Basin and Range Province is approximately 30 – 35 km and is comparable to extended continental crust around the world ... The crust in conjunction with the upper mantle comprises the lithosphere ...