Magmatism and tectonics of the Sierra Madre Occidental and its relation with the evolution of the western margin of North America

Author(s):  
Luca Ferrari ◽  
Martín Valencia-Moreno ◽  
Scott Bryan
Phytotaxa ◽  
2018 ◽  
Vol 338 (1) ◽  
pp. 33
Author(s):  
ROSA IVONNE GUTIÉRREZ-SÁNCHEZ ◽  
ARTURO CASTRO-CASTRO ◽  
JESÚS GUADALUPE GONZÁLEZ-GALLEGOS ◽  
IRMA LORENA LÓPEZ-ENRÍQUEZ ◽  
ALFREDO FRÍAS-CASTRO

The genus Lobelia is cosmopolitan and comprises 423 species in 18 sections. Lobelia sect. Stenotium is the most diverse group with 153 species, has a wide distribution in continental North America and is segregated into two subgroups based on the presence of spurred flowers. There are 16 spurred Lobelia species that occur in streamside or seep areas, throughout pine and oak mixed forests from USA to Costa Rica, but they are frequent along the Pacific slopes of the Sierra Madre Occidental (SMO), Mexico, where 10 species grow. In this paper we present a synopsis of the spurred species of Lobelia in the SMO and propose two new taxa. First, Lobelia rzedowskii is morphologically similar to L. ayersiae, L. cordifolia and L. endlichii but differs by its rosulate leaves, blades 0.5–1.5 × 0.4–1 cm, subsessile, racemose to paniculate inflorescences, with (4–)10–35(–191) flowers, flowers 4–6 mm long including hypanthium, spur 0.5–1 × 0.5–0.8 mm, with the lower two calyx lobes positioned at the middle portion of the spur, white corolla with a yellow spot above lobe sinuses on the throat and staminal tube 1.3–2.5 mm long. Second, Lobelia saturnini is morphologically similar to L. knoblochii, L. macrocentron, L. mcvaughii and L. villaregalis, but differs from them by leaves (2–)4–14(–17) mm long, petioles 2–6(–17) mm long, solitary flowers, flowers 12–16 mm long including hypanthium, hypanthium 1.2–2.5 mm long, spur 2–3 mm long, pedicels (1.3–)2–9(–12) cm long and anthers 1–2.2 mm long. We include an identification key for spurred species of Lobelia in the SMO, photographs, distribution notes with a map, and illustrations.


2020 ◽  
Author(s):  
Jordan M. Foote ◽  
◽  
Majie Fan ◽  
Aaron J. Martin ◽  
Lu Zhu

1983 ◽  
Vol 20 (9) ◽  
pp. 1389-1408 ◽  
Author(s):  
Philippe Erdmer ◽  
Herwart Helmstaedt

Eclogite occurring in central Yukon, at Faro and near Last Peak, as lenses interleaved with muscovite–quartz blastomylonite has the chemical and field characteristics of group C rocks. From sigmoidal inclusion trails in garnet, from geothermometry and geobarometry, and from mineral parageneses, the eclogite is inferred to have a crustal protolith and to have followed a hysteretic, subduction-cycle P–T trajectory. Transformation of basic igneous rock into schist was followed by eclogite metamorphism during which pressure was at least 1000 MPa and temperature was between 600 and 700 °C. Uplifting involved passage through the stability field of glaucophane; the eclogite and its host rocks were then subjected to greenschist fades metamorphism and deformation, with temperature at approximately 400 °C. The rocks were emplaced as thrust sheets against or onto the western North American cratonal margin. The tectonic boundary ranges from nearly vertical, where it is outlined by a zone of steeply dipping mélange, to nearly horizontal beneath klippen of cataclastic rocks that lie on North American miogeoclinal strata. Together with occurrences of eclogite on strike, in Yukon, near Fairbanks (Alaska), and near Pinchi Lake (British Columbia), eclogite at Faro and near Last Peak implies that the Yukon Cataclastic Complex is a deeply eroded collision mélange that borders over 1000 km of the ancient continental margin.


Zootaxa ◽  
2021 ◽  
Vol 5027 (3) ◽  
pp. 351-375
Author(s):  
TANIA ESCALANTE ◽  
GERARDO RODRÍGUEZ-TAPIA ◽  
JUAN J. MORRONE

We provide a preliminary nomenclatural proposal and a digital map of the Nearctic region, based on published regionalizations, especially Dice (1943), and applying the International Code of Area Nomenclature. The Nearctic region is comprised of three subregions (one of them with two dominions), one transition zone and 29 provinces. The Arctic subregion, in northern North America and Greenland, includes the Eskimoan, Hudsonian, Aleutian and Sitkan provinces. The Western subregion, in western North America, includes the Californian dominion, with the Californian and Oregonian provinces; and the Rocky Mountain dominion, including the Montanian, Saskatchewan, Palusian, Artemisian, Coloradan, Kansan, Mohavian, Navahonian, Sonoran, Chihuahuan, Comanche, and Baja California provinces. The Alleghany subregion, in eastern North America, includes the Illinoian, Canadian, Carolinian, Texan, Austroriparian, and Tamaulipan provinces. The Mexican Transition Zone, situated in the area of overlap with the Neotropical region, includes the Sierra Madre Occidental, Sierra Madre Oriental, Transmexican Volcanic Belt, Sierra Madre del Sur and Chiapas Highlands provinces.  


2017 ◽  
Vol 155 (1) ◽  
pp. 203-208
Author(s):  
ISMAEL FERRUSQUÍA-VILLAFRANCA ◽  
VÍCTOR ADRIÁN PÉREZ-CRESPO ◽  
JOSÉ E. RUIZ-GONZÁLEZ ◽  
ENRIQUE MARTÍNEZ-HERNÁNDEZ ◽  
PEDRO MORALES-PUENTE

AbstractThe diet and habitat ofLeptomeryxsp. from the Late Uintan Yolomécatl Formation of NW Oaxaca, SE Mexico were inferred using dental enamel carbon and oxygen isotopic relationships, and compared with those of congeneric species from temperate North America. Results show thatLeptomeryxsp. fed on C3 plants and lived in open forest or forest/savanna ecotone. The palynoflora and co-occurrence of perissodactyls and artiodactyls that live in an environment like that ofLeptomeryxsupport this interpretation. Further, both records disclose that in NW Oaxaca (southern North America) tropical conditions prevailed at that time, unlike that of temperate North America.


Geomorphology ◽  
2003 ◽  
Vol 55 (1-4) ◽  
pp. 235-247 ◽  
Author(s):  
David R. Montgomery ◽  
Jorge López-Blanco

2018 ◽  
Vol 34 (1) ◽  
pp. 1-6 ◽  
Author(s):  
José Hugo Martínez-Guerrero ◽  
Jorge Nocedal ◽  
Daniel Sierra-Franco ◽  
Samuel Ignacio Arroyo-Arroyo ◽  
Martín Emilio Pereda-Solís

The Sierra Madre Sparrow (Xenospiza baileyi) is an endemic species of Mexico that is threatened with extinction. Its distribution is reported in two areas: One in the Transvolcanic Belt of central Mexico (La Cima) near Mexico City and the other in the Sierra Madre Occidental in northwestern Mexico (Ejido Ojo de Agua El Cazador) near the city of Durango, in the state of Durango. The habitat is the same in these two areas, and consists of sub-alpine grassland that is located in shallow valleys or shallows. In our case, "El Bajío la Cantera" of approximately 55 hectares, is mostly used in rainfed agriculture, protected from livestock grazing with wire fences, which in turn represents protection for remnants of grassland where they are the birds. “El Bajío la Cantera" belongs to Ejido 12 de Mayo, Municipality of San Dimas, Durango, where 28 males were detected singing along a 500 meter transect. This finding represents the population of the healthiest Sierra Madre Sparrow currently known, so it would be necessary to document their population trend over time. This information can help to evaluate and propose the creation of a special protection area for the species that involves joint government actions and ejidatarios tending to conserve the habitat during the reproductive season in order to increase and / or maintain the size of the population.


2018 ◽  
Vol 13 (1) ◽  
pp. 69
Author(s):  
Lourdes Consuelo Pacheco-Ladrón de Guevara

Tanto la niñez como la adolescencia se consideran construcciones socioculturales enmarcadas en contextos específicos. De ahí que lejos de establecer parámetros genéricos sobre la adolescencia, su estudio particular permite especificar las formas de ser adolescente en situaciones concretas. En el presente documento se aborda la construcción de las masculinidades rurales indígenas desde la comunidad y la escuela telesecundaria, para lo cual se realizaron grupos focales y entrevistas a estudiantes indígenas de telesecundaria de la Sierra Madre Occidental durante los años 2010 y 2011. Se discute la importancia de abordar la construcción de las masculinidades adolescentes en el marco de la irrupción de la escuela telesecundaria en la zona indígena en función de que la escuela telesecundaria se ha convertido en el espacio de la adolescencia indígena rural. Se concluye que la escuela tiene posibilidades de convertirse en un espacio de discusión de las propuestas comunitarias tradicionales si es capaz de replantear la funcionalidad de las masculinidades en los contextos específicos a partir de las condiciones del grupo cultural.


Polibotánica ◽  
2017 ◽  
Vol 0 (43) ◽  
Author(s):  
M.Á. Macías-Rodríguez ◽  
J. Giménez de Azcárate-Cornide ◽  
L.F. Gopar-Merino

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