Matches in SemOpenAlex for { <https://semopenalex.org/work/W2099559840> ?p ?o ?g. }
- W2099559840 endingPage "13388" @default.
- W2099559840 startingPage "13373" @default.
- W2099559840 abstract "Descriptions of volcanic rocks in the Sierra Madre Occidental of western Mexico have thus far emphasized the widespread and nearly continuous cover of ash flow tuffs and other units attributed to the Oligocene ignimbrite flare‐up. However, much less attention has been given to the pre‐Oligocene volcanic sequence beneath this ash flow blanket. At Nazas, Durango, on the eastern flank of the Sierra Madre Occidental, a well‐exposed section includes voluminous felsic volcanic rocks of both Eocene and Oligocene age. The oldest igneous rocks at Nazas include a small exposure of intermediate volcanic breccias and lava flows that overlie Cretaceous limestones and apparently were deformed with them during Laramide tectonism. More commonly, the limestones are overlain by Tertiary volcanic rocks and continental clastic deposits. The Tertiary volcanic section is about 800 m thick, not including intercalated fanglomerates. The section records three distinct magmatic episodes: from 51 to 40 Ma, comprising felsic ash flow tuffs and intermediate lava flows and domes; a pulse at about 30 Ma, comprising voluminous felsic ash flow tuffs with an aggregate thickness of about 500 m; and from 24 to 20 Ma, comprising alkalic basalts. The Ahuichila Formation, a molasse‐type conglomerate up to 200 m thick that underlies the Tertiary volcanic section, was deposited during or just after the Laramide deformation. The Santa Inés Formation is a widespread fanglomerate, up to 110 m thick, that underlies the basalts and apparently accumulated during normal faulting. Eocene volcanism in the Nazas area is characterized by interfingering felsic ash flow tuffs and intermediate lava flows and domes. A similar sequence of Eocene volcanic rocks has been mapped in central Chihuahua state, about 350 km to the northwest of Nazas. Felsic tuffs interbedded with intermediate volcanic rocks older than 40 Ma are also exposed at Tayoltita, Durango, about 200 km southwest of Nazas. These occurrences suggest that a wider spectrum of compositions and volcanic styles existed during the Eocene than during the Oligocene in the Sierra Madre Occidental. Eocene volcanism was more typical of orogenic magmatic belts developed at continental margins, whereas the Oligocene activity was dominated by voluminous felsic ash flow tuffs erupted during a transition of tectonic setting from subduction along a continental margin to intraplate extension. In addition to these three areas, there are several other localities in western Mexico having volcanic rocks with reported ages between 40 and 53 Ma. It is possible that the volcanic field during the Eocene in Mexico was comparable in extent to that of the Oligocene. The Eocene volcanism in western Mexico was in part contemporaneous with the Challis volcanic episode of northwestern United States and its extension into western Canada. However, Eocene magmatism in the Pacific Northwest apparently developed in an extensional tectonic setting, whereas in Mexico no evidence for Eocene extensional deformation is known." @default.
- W2099559840 created "2016-06-24" @default.
- W2099559840 creator A5004381189 @default.
- W2099559840 creator A5013950229 @default.
- W2099559840 date "1991-07-30" @default.
- W2099559840 modified "2023-10-14" @default.
- W2099559840 title "The volcanic section at Nazas, Durango, Mexico, and the possibility of widespread Eocene volcanism within the Sierra Madre Occidental" @default.
- W2099559840 cites W1981653133 @default.
- W2099559840 cites W1981807101 @default.
- W2099559840 cites W1997529291 @default.
- W2099559840 cites W2007520293 @default.
- W2099559840 cites W2015941889 @default.
- W2099559840 cites W2024835978 @default.
- W2099559840 cites W2030964036 @default.
- W2099559840 cites W2037587012 @default.
- W2099559840 cites W2052662144 @default.
- W2099559840 cites W2056232757 @default.
- W2099559840 cites W2058257558 @default.
- W2099559840 cites W2066907116 @default.
- W2099559840 cites W2067112977 @default.
- W2099559840 cites W2067654075 @default.
- W2099559840 cites W2070386120 @default.
- W2099559840 cites W2073415075 @default.
- W2099559840 cites W2082137170 @default.
- W2099559840 cites W2085513759 @default.
- W2099559840 cites W2087888055 @default.
- W2099559840 cites W2087944109 @default.
- W2099559840 cites W2090668949 @default.
- W2099559840 cites W2103151937 @default.
- W2099559840 cites W2108641227 @default.
- W2099559840 cites W2116453115 @default.
- W2099559840 cites W2122897032 @default.
- W2099559840 cites W2151557722 @default.
- W2099559840 cites W2155500845 @default.
- W2099559840 cites W2161665601 @default.
- W2099559840 cites W2166306138 @default.
- W2099559840 cites W2166792459 @default.
- W2099559840 cites W2255004000 @default.
- W2099559840 cites W2307479209 @default.
- W2099559840 cites W2328793185 @default.
- W2099559840 cites W2343488851 @default.
- W2099559840 cites W2439185781 @default.
- W2099559840 cites W2470565841 @default.
- W2099559840 cites W2482556661 @default.
- W2099559840 cites W2482734072 @default.
- W2099559840 cites W2506071339 @default.
- W2099559840 cites W2977879045 @default.
- W2099559840 cites W4205749704 @default.
- W2099559840 cites W4293069799 @default.
- W2099559840 cites W4293860446 @default.
- W2099559840 doi "https://doi.org/10.1029/91jb00245" @default.
- W2099559840 hasPublicationYear "1991" @default.
- W2099559840 type Work @default.
- W2099559840 sameAs 2099559840 @default.
- W2099559840 citedByCount "55" @default.
- W2099559840 countsByYear W20995598402012 @default.
- W2099559840 countsByYear W20995598402013 @default.
- W2099559840 countsByYear W20995598402014 @default.
- W2099559840 countsByYear W20995598402015 @default.
- W2099559840 countsByYear W20995598402016 @default.
- W2099559840 countsByYear W20995598402017 @default.
- W2099559840 countsByYear W20995598402018 @default.
- W2099559840 countsByYear W20995598402019 @default.
- W2099559840 countsByYear W20995598402020 @default.
- W2099559840 countsByYear W20995598402021 @default.
- W2099559840 countsByYear W20995598402022 @default.
- W2099559840 crossrefType "journal-article" @default.
- W2099559840 hasAuthorship W2099559840A5004381189 @default.
- W2099559840 hasAuthorship W2099559840A5013950229 @default.
- W2099559840 hasConcept C106804226 @default.
- W2099559840 hasConcept C113754120 @default.
- W2099559840 hasConcept C120806208 @default.
- W2099559840 hasConcept C127313418 @default.
- W2099559840 hasConcept C151730666 @default.
- W2099559840 hasConcept C161509811 @default.
- W2099559840 hasConcept C17409809 @default.
- W2099559840 hasConcept C192241223 @default.
- W2099559840 hasConcept C193429443 @default.
- W2099559840 hasConcept C42787717 @default.
- W2099559840 hasConcept C62074269 @default.
- W2099559840 hasConcept C6494504 @default.
- W2099559840 hasConcept C95869378 @default.
- W2099559840 hasConceptScore W2099559840C106804226 @default.
- W2099559840 hasConceptScore W2099559840C113754120 @default.
- W2099559840 hasConceptScore W2099559840C120806208 @default.
- W2099559840 hasConceptScore W2099559840C127313418 @default.
- W2099559840 hasConceptScore W2099559840C151730666 @default.
- W2099559840 hasConceptScore W2099559840C161509811 @default.
- W2099559840 hasConceptScore W2099559840C17409809 @default.
- W2099559840 hasConceptScore W2099559840C192241223 @default.
- W2099559840 hasConceptScore W2099559840C193429443 @default.
- W2099559840 hasConceptScore W2099559840C42787717 @default.
- W2099559840 hasConceptScore W2099559840C62074269 @default.
- W2099559840 hasConceptScore W2099559840C6494504 @default.
- W2099559840 hasConceptScore W2099559840C95869378 @default.
- W2099559840 hasIssue "B8" @default.
- W2099559840 hasLocation W20995598401 @default.
- W2099559840 hasOpenAccess W2099559840 @default.