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- W2040278872 abstract "Abstract Lower Palaeozoic rocks crop out extensively in Wales, the Lake District of northern England and the Southern Uplands of Scotland; they also form the subcrop concealed beneath the English Midlands and East Anglia. These mainly marine sedimentary rocks were deposited in basins created during plate tectonic assembly of the various terranes that amalgamated to form the British Isles, 400-600 Ma ago. Final amalgamation occurred during the late Lower Devonian Acadian Orogeny when the basins were uplifted and deformed, producing belts of cleaved, low-grade metasediments, so-called slate belts, with a predominantly Caledonian (NE-SW) trend. The clay mineralogy of mudrock lithologies - including mudstone, shale and slate - found in these belts is reviewed. Using X-ray diffraction data from the <2 μm fractions of ~4500 mudrocks samples, clay mineral assemblages are summarized and discussed in terms of diagenetic and low-grade metamorphic reactions, and the metapelitic grade indicated by the Kübler index of illite crystallinity. Two sequences of clay mineral assemblages, or regional assemblages, are recognized. Regional Assemblage A is characterized by a greater diversity of clay minerals in assemblages from all metapelitic grades. It includes K-rich, intermediate Na/K and Na-rich white micas, chlorite and minor amounts of pyrophyllite. Corrensite, rectorite and pyrophyllite are found in the clay assemblages of contact or hydrothermally altered mudstones. K-white micas are aluminous and phengite-poor, with b cell dimensions in the range 8.98-9.02 Å. Regional Assemblage B has fewer clay minerals in assemblages from a range of metapelitic grades. Phengite-rich K-mica is characteristic whereas Na- micas are rare, and absent in most assemblages; chlorite is present and minor corrensite occurs in mudrocks with mafic-rich detritus. Minor amounts of kaolinite are sporadically present, but dickite and nacrite are rare; pyrophyllite and rectorite are generally absent. The b cell dimensions of K-white mica in Regional Assemblage B are in the range 9.02-9.06 Å. The two regional assemblages are found in contrasting geotectonic settings. Regional Assemblage A is characteristic of the extensional basin settings of Wales, the northern Lake District and the Isle of Man. These basins have a history of early burial metamorphism associated with extension, and syn-burial or post-burial intrusive and extrusive volcanic activity. Intermediate Na/K mica probably developed from hydrothermal fluids generated around submarine volcanic centres. Deep diagenetic and low anchizonal clay mineral in these basins may develop a bedding-parallel microfabric. Chlorite-mica stacks also occur in the extensional basins and the stacking planes represent another type of bedding-parallel microfabric. Both types of microfabric are non-tectonic and developed by burial during the extensional phase of basin evolution. Regional Assemblage B is developed in the plate-convergent settings of the Southern Uplands and the southern Lake District. In the accretionary complex of the Southern Uplands the processes of burial diagenesis, metamorphism and tectonism were synchronous events. In both plate- convergent basins, low temperatures and tectonic fabric-formation had an important role in clay mineral reactions, whereas hydrothermal fluids played no part in clay genesis." @default.
- W2040278872 created "2016-06-24" @default.
- W2040278872 creator A5054567522 @default.
- W2040278872 date "2006-03-01" @default.
- W2040278872 modified "2023-10-16" @default.
- W2040278872 title "Clay mineral assemblages in British Lower Palaeozoic mudrocks" @default.
- W2040278872 cites W1599931192 @default.
- W2040278872 cites W1604980370 @default.
- W2040278872 cites W1967652944 @default.
- W2040278872 cites W1969426269 @default.
- W2040278872 cites W1971152515 @default.
- W2040278872 cites W1972609088 @default.
- W2040278872 cites W1974957867 @default.
- W2040278872 cites W1975069941 @default.
- W2040278872 cites W1976639625 @default.
- W2040278872 cites W1980002621 @default.
- W2040278872 cites W1983760834 @default.
- W2040278872 cites W1987590114 @default.
- W2040278872 cites W1987879909 @default.
- W2040278872 cites W1988181429 @default.
- W2040278872 cites W1994184948 @default.
- W2040278872 cites W1995489773 @default.
- W2040278872 cites W1996227789 @default.
- W2040278872 cites W1996832287 @default.
- W2040278872 cites W1997175123 @default.
- W2040278872 cites W1998777848 @default.
- W2040278872 cites W1999574375 @default.
- W2040278872 cites W2005463006 @default.
- W2040278872 cites W2006391679 @default.
- W2040278872 cites W2008021984 @default.
- W2040278872 cites W2009880149 @default.
- W2040278872 cites W2013194393 @default.
- W2040278872 cites W2017031499 @default.
- W2040278872 cites W2017813249 @default.
- W2040278872 cites W2020721681 @default.
- W2040278872 cites W2023412179 @default.
- W2040278872 cites W2023537298 @default.
- W2040278872 cites W2025047407 @default.
- W2040278872 cites W2031352383 @default.
- W2040278872 cites W2033191237 @default.
- W2040278872 cites W2045529194 @default.
- W2040278872 cites W2048462534 @default.
- W2040278872 cites W2049382682 @default.
- W2040278872 cites W2049759116 @default.
- W2040278872 cites W2052308466 @default.
- W2040278872 cites W2052694638 @default.
- W2040278872 cites W2055071952 @default.
- W2040278872 cites W2062297270 @default.
- W2040278872 cites W2063723429 @default.
- W2040278872 cites W2067113638 @default.
- W2040278872 cites W2067831462 @default.
- W2040278872 cites W2071726955 @default.
- W2040278872 cites W2072830841 @default.
- W2040278872 cites W2073014111 @default.
- W2040278872 cites W2073040869 @default.
- W2040278872 cites W2073235370 @default.
- W2040278872 cites W2075618665 @default.
- W2040278872 cites W2077960450 @default.
- W2040278872 cites W2081707150 @default.
- W2040278872 cites W2087131645 @default.
- W2040278872 cites W2089950189 @default.
- W2040278872 cites W2092273609 @default.
- W2040278872 cites W2095051348 @default.
- W2040278872 cites W2095479860 @default.
- W2040278872 cites W2101713821 @default.
- W2040278872 cites W2104139642 @default.
- W2040278872 cites W2106049107 @default.
- W2040278872 cites W2107953152 @default.
- W2040278872 cites W2108833866 @default.
- W2040278872 cites W2113354090 @default.
- W2040278872 cites W2116905083 @default.
- W2040278872 cites W2121308759 @default.
- W2040278872 cites W2132912144 @default.
- W2040278872 cites W2135825315 @default.
- W2040278872 cites W2136310936 @default.
- W2040278872 cites W2139105466 @default.
- W2040278872 cites W2140401851 @default.
- W2040278872 cites W2147656762 @default.
- W2040278872 cites W2153022393 @default.
- W2040278872 cites W2156252765 @default.
- W2040278872 cites W2156697783 @default.
- W2040278872 cites W2157439685 @default.
- W2040278872 cites W2164544947 @default.
- W2040278872 cites W2168209875 @default.
- W2040278872 cites W2168508131 @default.
- W2040278872 cites W2171243662 @default.
- W2040278872 cites W2171655306 @default.
- W2040278872 cites W2183075754 @default.
- W2040278872 cites W2331592735 @default.
- W2040278872 cites W2414691375 @default.
- W2040278872 cites W2601144783 @default.
- W2040278872 cites W2605116902 @default.
- W2040278872 cites W2112558844 @default.
- W2040278872 doi "https://doi.org/10.1180/0009855064110204" @default.
- W2040278872 hasPublicationYear "2006" @default.
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