Matches in SemOpenAlex for { <https://semopenalex.org/work/W2072800705> ?p ?o ?g. }
- W2072800705 endingPage "379" @default.
- W2072800705 startingPage "356" @default.
- W2072800705 abstract "The Precambrian geology of west-central Madagascar is reviewed and re-interpreted in light of new field observations, Landsat Thematic Mapper image analysis, and U–Pb geochronology. The bedrock of the area consists of: (1) late Archean (to Paleoproterozoic) migmatite gneiss and schist; (2) Mesoproterozoic stratified rocks (Itremo, Amborompotsy, and Malakialina Groups) perhaps deposited unconformably on the older metamorphic rocks (1, above); (3) Proterozoic (∼ 1000 Ma–720 Ma) plutonic rocks emplaced into both units above (1 and 2), and; (4) latest Neoproterozoic to middle Cambrian (∼ 570–520 Ma) granitoids emplaced as regionally discordant and weakly foliated plutons throughout the regions. The effects of Neoproterozoic orogenic processes are widespread throughout the region and our observations and isotopic measurements provide important constraints on the tectonic history of the region: (i) Archean gneisses and Mesoproterozoic stratified rocks are the crystalline basement and platformal sedimentary cover, respectively, of a continental fragment of undetermined tectonic affinity (East or West Gondwanan, or neither). (ii) This continental fragment (both basement and cover) was extensively invaded by subduction-related plutons in the period from ∼ 1000 Ma to ∼ 720 Ma that were emplaced prior to the onset of regional metamorphism and deformation. (iii) Continental collision related to Gondwana's amalgamation began after ∼ 720 Ma and before ∼ 570 Ma. Collision related deformation and metamorphism continued throughout the rest of the Neoproterozoic with thermal effects that lasted until ∼ 520 Ma. The oldest structures produced during continental collision were km-scale fold- and thrust-nappes with east or southeast-directed vergence (present-day direction). They resulted in the inversion and repetition of Archean and Proterozoic rocks throughout the region. During this early phase of convergence warm rocks were thrust over cool rocks thereby producing the present distribution of regional metamorphic isograds. The vergence of the nappes and the distribution of metamorphic rocks are consistent with their formation within a zone of west or northwest-dipping continental convergence (present-day direction). (iv) Later upright folding of the nappes (and related folds and thrusts) produced km-scale interference fold patterns. The geometry and orientation of these younger upright folds is consistent with E–W horizontal shortening (present-day direction) within a sinistral transpressive regime. We relate this final phase of deformation to motion along the Ranotsara and related shear zones of south Madagascar, and to the initial phases of lower crustal exhumation and extensional tectonics within greater Gondwana." @default.
- W2072800705 created "2016-06-24" @default.
- W2072800705 creator A5039177320 @default.
- W2072800705 creator A5045897339 @default.
- W2072800705 creator A5049125532 @default.
- W2072800705 creator A5084065512 @default.
- W2072800705 date "2007-11-01" @default.
- W2072800705 modified "2023-09-27" @default.
- W2072800705 title "Neoproterozoic nappes and superposed folding of the Itremo Group, west-central Madagascar" @default.
- W2072800705 cites W1966256034 @default.
- W2072800705 cites W1978711316 @default.
- W2072800705 cites W1978991677 @default.
- W2072800705 cites W1983567888 @default.
- W2072800705 cites W1984458536 @default.
- W2072800705 cites W1987132569 @default.
- W2072800705 cites W1994705921 @default.
- W2072800705 cites W2007105153 @default.
- W2072800705 cites W2017299757 @default.
- W2072800705 cites W2022380505 @default.
- W2072800705 cites W2026969831 @default.
- W2072800705 cites W2032366241 @default.
- W2072800705 cites W2037508924 @default.
- W2072800705 cites W2039135265 @default.
- W2072800705 cites W2040371906 @default.
- W2072800705 cites W2044911484 @default.
- W2072800705 cites W2048952741 @default.
- W2072800705 cites W2060282393 @default.
- W2072800705 cites W2064495722 @default.
- W2072800705 cites W2075683682 @default.
- W2072800705 cites W2077937451 @default.
- W2072800705 cites W2078553842 @default.
- W2072800705 cites W2083921875 @default.
- W2072800705 cites W2088559528 @default.
- W2072800705 cites W2094677227 @default.
- W2072800705 cites W2096263763 @default.
- W2072800705 cites W2100855258 @default.
- W2072800705 cites W2101695533 @default.
- W2072800705 cites W2106007745 @default.
- W2072800705 cites W2107742656 @default.
- W2072800705 cites W2114893924 @default.
- W2072800705 cites W2116238917 @default.
- W2072800705 cites W2119802751 @default.
- W2072800705 cites W2137543000 @default.
- W2072800705 cites W2140420429 @default.
- W2072800705 cites W2144067924 @default.
- W2072800705 cites W2150049829 @default.
- W2072800705 cites W2174216460 @default.
- W2072800705 cites W2316633540 @default.
- W2072800705 cites W4245340369 @default.
- W2072800705 doi "https://doi.org/10.1016/j.gr.2006.12.001" @default.
- W2072800705 hasPublicationYear "2007" @default.
- W2072800705 type Work @default.
- W2072800705 sameAs 2072800705 @default.
- W2072800705 citedByCount "65" @default.
- W2072800705 countsByYear W20728007052012 @default.
- W2072800705 countsByYear W20728007052013 @default.
- W2072800705 countsByYear W20728007052014 @default.
- W2072800705 countsByYear W20728007052015 @default.
- W2072800705 countsByYear W20728007052016 @default.
- W2072800705 countsByYear W20728007052017 @default.
- W2072800705 countsByYear W20728007052018 @default.
- W2072800705 countsByYear W20728007052019 @default.
- W2072800705 countsByYear W20728007052020 @default.
- W2072800705 countsByYear W20728007052021 @default.
- W2072800705 countsByYear W20728007052022 @default.
- W2072800705 countsByYear W20728007052023 @default.
- W2072800705 crossrefType "journal-article" @default.
- W2072800705 hasAuthorship W2072800705A5039177320 @default.
- W2072800705 hasAuthorship W2072800705A5045897339 @default.
- W2072800705 hasAuthorship W2072800705A5049125532 @default.
- W2072800705 hasAuthorship W2072800705A5084065512 @default.
- W2072800705 hasConcept C112764850 @default.
- W2072800705 hasConcept C127313418 @default.
- W2072800705 hasConcept C127413603 @default.
- W2072800705 hasConcept C147176958 @default.
- W2072800705 hasConcept C149347711 @default.
- W2072800705 hasConcept C151730666 @default.
- W2072800705 hasConcept C153220577 @default.
- W2072800705 hasConcept C171701179 @default.
- W2072800705 hasConcept C173776410 @default.
- W2072800705 hasConcept C17409809 @default.
- W2072800705 hasConcept C201867031 @default.
- W2072800705 hasConcept C26687426 @default.
- W2072800705 hasConcept C2781148125 @default.
- W2072800705 hasConcept C2781297371 @default.
- W2072800705 hasConcept C34122518 @default.
- W2072800705 hasConcept C53942344 @default.
- W2072800705 hasConcept C58097730 @default.
- W2072800705 hasConcept C75643213 @default.
- W2072800705 hasConcept C77928131 @default.
- W2072800705 hasConcept C78519656 @default.
- W2072800705 hasConcept C93033518 @default.
- W2072800705 hasConceptScore W2072800705C112764850 @default.
- W2072800705 hasConceptScore W2072800705C127313418 @default.
- W2072800705 hasConceptScore W2072800705C127413603 @default.
- W2072800705 hasConceptScore W2072800705C147176958 @default.
- W2072800705 hasConceptScore W2072800705C149347711 @default.
- W2072800705 hasConceptScore W2072800705C151730666 @default.