Skiddaw Slate

Skiddaw slate is an early

Ordovician The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. T ...

metamorphosed

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

, as first identified on the slopes of

Skiddaw Skiddaw is a mountain in the Lake District National Park in England. Its summit is the sixth-highest in England. It lies just north of the town of Keswick, Cumbria, and dominates the skyline in this part of the northern lakes. It is the ...

in the

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ...

Lake District The Lake District, also known as the Lakes or Lakeland, is a mountainous region in North West England. A popular holiday destination, it is famous for its lakes, forests, and mountains (or '' fells''), and its associations with William Wordswor ...

. The base of this series is unknown. The thickness could, therefore, amount to several thousand feet of sediment. These sediments were formed about 500 mya by deposition in a shallow sea, low-energy environment. The series contains differing grain sizes and comprises

grits Grits are a type of porridge made from boiled cornmeal. Hominy grits are a type of grits made from hominy – corn that has been treated with an alkali in a process called nixtamalization, with the pericarp (ovary wall) removed. Grits are of ...

flag A flag is a piece of fabric (most often rectangular or quadrilateral) with a distinctive design and colours. It is used as a symbol, a signalling device, or for decoration. The term ''flag'' is also used to refer to the graphic design empl ...

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especiall ...

s and

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology.' ...

s. In some places, there is evidence of

intrusion In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

of Skiddaw Granite into the Skiddaw Slates, close to the anticlinal axis of the Lake District. Skiddaw slate has a grey hue (as opposed to Honister slate which has a green hue) and is used for building, in the Lake District. The traditional buildings of Keswick and other settlements are almost entirely of Skiddaw slate. The slate is also used for making souvenirs, monuments, ornaments etc. Smaller fragments are used for gravels or for ornamental pathways. Geologic formations of England Ordovician System of Europe Ordovician England Lower Ordovician Series Shale formations Slate industry in the United Kingdom Mining in Cumbria Geology of Cumbria {{UK-geologic-formation-stub