Geological Society, London, Special Publications, 2019
Granites (sensu lato) come in many types and flavours, defining distinct magmatic series/suites/t... more Granites (sensu lato) come in many types and flavours, defining distinct magmatic series/suites/types. A good classification not only gives generally accepted and understandable names to similar rocks but also links the bulk chemical composition to the stoichiometry of the constituent minerals and, potentially, also to the likely source, magmatic evolution and tectonic setting.The ‘ideal’ granitoid classification should be based on chemical criteria amenable to an objective treatment. Statistical analysis helps to identify the most discriminant variables. The key properties are (1) acidity/maficity, (2) alkalinity (balance of Na + K v. Ca), (3) aluminosity (balance of Al v. Ca, Na and K), (4) Fe/Mg balance and (5) Na/K balance and K contents at the given SiO2 level. These are used by successful classifications, e.g. the I/S dichotomy is based mainly on aluminosity, while the Frost et al. (2001; ‘A geochemical classification for granitic rocks', Journal of Petrology, 42, 2033–204...
In SE China the Fuzhou plutonic complex is made up of two major suites:a) A calc-alkaline suite (... more In SE China the Fuzhou plutonic complex is made up of two major suites:a) A calc-alkaline suite (Danyang, Fuzhou) emplaced about 105-100 Ma ago (Rb-Sr ages). These granitic rocks show a calc-alkaline differentiation trend, with fractionation of plagioclase and hornblende. Sr and Nd isotopic evidence suggests that ancient crustal material has played an important role in the magma genesis.b) An alkaline suite intruded about 90 Ma ago (Kuiqi, Bijiashan). It is composed of hypersolvus per-alkaline granites, which show little magmatic differentiation. These rocks are characterized by high abundances of REE. Sr and Nd isotopic data indicate that crust involvement was not significant.The petrogenetic study suggests that the successive intrusions of that complex were emplaced progressively at higher crustal levels. The calc-alkaline suite is typical of those emplaced in subduction-zone environments, whereas the hyperalkaline suite is associated with major deep crustal faults.
Geological Society, London, Special Publications, 2019
Granites (sensu lato) come in many types and flavours, defining distinct magmatic series/suites/t... more Granites (sensu lato) come in many types and flavours, defining distinct magmatic series/suites/types. A good classification not only gives generally accepted and understandable names to similar rocks but also links the bulk chemical composition to the stoichiometry of the constituent minerals and, potentially, also to the likely source, magmatic evolution and tectonic setting.The ‘ideal’ granitoid classification should be based on chemical criteria amenable to an objective treatment. Statistical analysis helps to identify the most discriminant variables. The key properties are (1) acidity/maficity, (2) alkalinity (balance of Na + K v. Ca), (3) aluminosity (balance of Al v. Ca, Na and K), (4) Fe/Mg balance and (5) Na/K balance and K contents at the given SiO2 level. These are used by successful classifications, e.g. the I/S dichotomy is based mainly on aluminosity, while the Frost et al. (2001; ‘A geochemical classification for granitic rocks', Journal of Petrology, 42, 2033–204...
In SE China the Fuzhou plutonic complex is made up of two major suites:a) A calc-alkaline suite (... more In SE China the Fuzhou plutonic complex is made up of two major suites:a) A calc-alkaline suite (Danyang, Fuzhou) emplaced about 105-100 Ma ago (Rb-Sr ages). These granitic rocks show a calc-alkaline differentiation trend, with fractionation of plagioclase and hornblende. Sr and Nd isotopic evidence suggests that ancient crustal material has played an important role in the magma genesis.b) An alkaline suite intruded about 90 Ma ago (Kuiqi, Bijiashan). It is composed of hypersolvus per-alkaline granites, which show little magmatic differentiation. These rocks are characterized by high abundances of REE. Sr and Nd isotopic data indicate that crust involvement was not significant.The petrogenetic study suggests that the successive intrusions of that complex were emplaced progressively at higher crustal levels. The calc-alkaline suite is typical of those emplaced in subduction-zone environments, whereas the hyperalkaline suite is associated with major deep crustal faults.
Uploads
Papers by Bernard Bonin