Matches in SemOpenAlex for { <https://semopenalex.org/work/W2079397966> ?p ?o ?g. }
Showing items 1 to 77 of
77
with 100 items per page.
- W2079397966 endingPage "382" @default.
- W2079397966 startingPage "369" @default.
- W2079397966 abstract "Abstract Changes in the sedimentologic and stratigraphic characteristics of the coal-bearing middle Oligocene–late Miocene siliciclastic Amaga Formation, northwestern Colombia, reflect major fluctuations in the stratigraphic base level within the Amaga Basin, which paralleled three major stages of evolution of the middle Cenozoic Andean Orogeny. These stages, which are also traceable by the changes in the compositional modes of sandstones, controlled the occurrence of important coal deposits. The initial stage of evolution of the Amaga Basin was related to the initial uplift of the Central Cordillera of Colombia around 25 Ma, which promoted moderate subsidence rates and high rates of sediment supply into the basin. This allowed the development of aggradational braided rivers and widespread channel amalgamation resulting in poor preservation of both, low energy facies and geomorphic elements. The presence of poorly preserved Alfisols within the scarce flood plains and the absence of swamp deposits suggest arid climate during this stage. The compositional modes of sandstones suggest sediment supply from uplifted basement-cored blocks. The second stage of evolution was related to the late Oligocene eastward migration of the Pre-Andean tholeitic magmatic arc from the Western Cordillera towards the Cauca depression. This generated extensional movements along the Amaga Basin, enhancing the subsidence and increasing the accommodation space along the basin. As a result of the enhanced subsidence rates, meandering rivers developed, allowing the formation of extensive swamps deposits (currently coal beds). The excellent preservation of Entisols and Alfisols within the flood plain deposits suggests rapid channels migration and a humid climate during deposition. Moderate to highly mature channel sandstones support this contention, and point out the Central Cordillera of Colombia as the main source of sediment. Enhanced subsidence during this stage also prevented channels amalgamation and promoted both, high preservation of geomorphic elements and high diversity of sedimentary facies. This resulted in the most symmetric stratigraphic cycles of the entire Amaga Formation. The final stage of evolution of the Amaga Basin was related to the early stage of development of the late Miocene northwestern Andes tholeitic volcanism (from ∼10 to ∼8 Ma). The extensive thrusting and folding associated to this volcanism reduced the subsidence rates along the basin and thus the accommodation space. This permitted the development of highly aggradational braided rivers and promoted channels amalgamation. Little preservation of low energy facies, poor preservation of the geomorphic elements and a complete obliteration of important swamp deposits (coal beds) within the basin are reflected by the most asymmetric stratigraphic cycles of the whole formation. The presence of greenish/reddish flood plain deposits and Alfisols suggests a dry climate during this depositional stage. The presence of channel sandstones with high contents of volcanic rock fragments supports a dry climate, and suggests an incipient phase of the Combia tholeiitic magmatism present during deposition of the Amaga Formation. The subsequent eastward migration of the NW Andes magmatic arc (after ∼8 Ma) may have produced basin inversion and suppressed deposition along the Amaga Basin." @default.
- W2079397966 created "2016-06-24" @default.
- W2079397966 creator A5017022187 @default.
- W2079397966 creator A5031668559 @default.
- W2079397966 creator A5039474489 @default.
- W2079397966 date "2008-12-01" @default.
- W2079397966 modified "2023-10-01" @default.
- W2079397966 title "Tectonic and climate driven fluctuations in the stratigraphic base level of a Cenozoic continental coal basin, northwestern Andes" @default.
- W2079397966 cites W1519752140 @default.
- W2079397966 cites W1758111190 @default.
- W2079397966 cites W2012368295 @default.
- W2079397966 cites W2019531731 @default.
- W2079397966 cites W2020415754 @default.
- W2079397966 cites W2057987054 @default.
- W2079397966 cites W2067628429 @default.
- W2079397966 cites W2074438535 @default.
- W2079397966 cites W2089231949 @default.
- W2079397966 cites W2138225088 @default.
- W2079397966 cites W2140973288 @default.
- W2079397966 cites W2151198756 @default.
- W2079397966 cites W2158923311 @default.
- W2079397966 cites W2166876167 @default.
- W2079397966 cites W2171756058 @default.
- W2079397966 cites W2497282204 @default.
- W2079397966 doi "https://doi.org/10.1016/j.jsames.2008.02.001" @default.
- W2079397966 hasPublicationYear "2008" @default.
- W2079397966 type Work @default.
- W2079397966 sameAs 2079397966 @default.
- W2079397966 citedByCount "22" @default.
- W2079397966 countsByYear W20793979662012 @default.
- W2079397966 countsByYear W20793979662014 @default.
- W2079397966 countsByYear W20793979662015 @default.
- W2079397966 countsByYear W20793979662017 @default.
- W2079397966 countsByYear W20793979662018 @default.
- W2079397966 countsByYear W20793979662019 @default.
- W2079397966 countsByYear W20793979662020 @default.
- W2079397966 countsByYear W20793979662021 @default.
- W2079397966 countsByYear W20793979662023 @default.
- W2079397966 crossrefType "journal-article" @default.
- W2079397966 hasAuthorship W2079397966A5017022187 @default.
- W2079397966 hasAuthorship W2079397966A5031668559 @default.
- W2079397966 hasAuthorship W2079397966A5039474489 @default.
- W2079397966 hasBestOaLocation W20793979662 @default.
- W2079397966 hasConcept C109007969 @default.
- W2079397966 hasConcept C114793014 @default.
- W2079397966 hasConcept C127313418 @default.
- W2079397966 hasConcept C151730666 @default.
- W2079397966 hasConcept C73707237 @default.
- W2079397966 hasConcept C77928131 @default.
- W2079397966 hasConceptScore W2079397966C109007969 @default.
- W2079397966 hasConceptScore W2079397966C114793014 @default.
- W2079397966 hasConceptScore W2079397966C127313418 @default.
- W2079397966 hasConceptScore W2079397966C151730666 @default.
- W2079397966 hasConceptScore W2079397966C73707237 @default.
- W2079397966 hasConceptScore W2079397966C77928131 @default.
- W2079397966 hasIssue "4" @default.
- W2079397966 hasLocation W20793979661 @default.
- W2079397966 hasLocation W20793979662 @default.
- W2079397966 hasOpenAccess W2079397966 @default.
- W2079397966 hasPrimaryLocation W20793979661 @default.
- W2079397966 hasRelatedWork W1624477729 @default.
- W2079397966 hasRelatedWork W2101333943 @default.
- W2079397966 hasRelatedWork W2104696163 @default.
- W2079397966 hasRelatedWork W2159575692 @default.
- W2079397966 hasRelatedWork W2161430494 @default.
- W2079397966 hasRelatedWork W2350447735 @default.
- W2079397966 hasRelatedWork W2355596537 @default.
- W2079397966 hasRelatedWork W2368415085 @default.
- W2079397966 hasRelatedWork W2387551409 @default.
- W2079397966 hasRelatedWork W2393371679 @default.
- W2079397966 hasVolume "26" @default.
- W2079397966 isParatext "false" @default.
- W2079397966 isRetracted "false" @default.
- W2079397966 magId "2079397966" @default.
- W2079397966 workType "article" @default.