Search results
Results from the WOW.Com Content Network
Rocks exhibiting foliation include the standard sequence formed by the prograde metamorphism of mudrocks; slate, phyllite, schist and gneiss. The slatey cleavage typical of slate is due to the preferred orientation of microscopic phyllosilicate crystals. In gneiss, the foliation is more typically represented by compositional banding due to ...
Phyllite Photomicrograph of thin section of phyllite (in cross polarised light) Fractured Duke stone showing phyllitic texture Phyllite. Phyllite (/ ˈ f ɪ l aɪ t / FIL-yte) is a type of foliated metamorphic rock formed from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation. [1]
Slate can be made into roofing slate, a type of roof tile which are installed by a slater. Slate has two lines of breakability—cleavage and grain—which make it possible to split the stone into thin sheets. When broken, slate retains a natural appearance while remaining relatively flat and easy to stack.
The formation was originally designated as the Hondo Slate by Evan Just in his 1937 survey of pegmatites in northern New Mexico. [5] However, this name conflicted with other unit names, and it was renamed the Pilar Phyllite Member of the Ortega Formation by Arthur Montgomery in 1953 [6] Bauer and Williams promoted it to formation rank within the Vadito Group in their sweeping revision of the ...
At depths greater than about 5 kilometers (3.1 mi), cataclasites appear; these are quite hard rocks consist of crushed rock fragments in a flinty matrix, which forms only at elevated temperature. At still greater depths, where temperatures exceed 300 °C (572 °F), plastic deformation takes over, and the fault zone is composed of mylonite .
Foliated metaconglomerate is created under the same metamorphic conditions that produce slate or phyllite, but with the parent rock being conglomerate, rather than clay. [2] The metaconglomerates of the Jack Hills of Western Australia are the source rocks for much of the detrital zircons that have been dated to be as old as 4.4 billion years.
Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Do not translate text that appears unreliable or low-quality.
Better minor A commonly used term for the choice of minor suit opening bid with less than four cards, typically in five card major systems. In Standard American Yellow Card, it is normal to bid the longer suit with 3 cards in one and two in the other, and 1 ♣ with 3–3. In this sense the term is a misnomer as a poor club suit (e.g. Jxx) may ...