干旱区生态环境知识资源中心(Arid): Reconnaissance geology and geophysics of the Mercurio structural dome, Chihuahua, Mexico

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DOI	10.22201/cgeo.20072902e.2019.3.1340
	Reconnaissance geology and geophysics of the Mercurio structural dome, Chihuahua, Mexico
	Jorge Aranda-Gomez, Jose; Yutsis, Vsevolod; Juarez Arriaga, Edgar; Ortega-Obregon, Carlos; Gonzalez-Cervantes, Norma; Chavez-Cabello, Gabriel; Francisco Ramirez-Pena, Cesar; Ernesto Torres-Gaytan, David
通讯作者	Aranda-Gomez, JJ (corresponding author), Univ Nacl Autonoma Mexico, Ctr Geociencias, Campus Juriquilla, Queretaro 76230, Qro, Mexico.
来源期刊	REVISTA MEXICANA DE CIENCIAS GEOLOGICAS
ISSN	1026-8774
出版年	2019
卷号	36 期号:3 页码:357-377
英文摘要	The Mercurio structural dome is a poorly exposed and complex structure located in the transitional region between the Coahuila Calcareous Platform and the San Pedro El Gallo sector of the Sierra Madre Oriental, Mexico. It is located in the State of Chihuahua, close to the limits with Coahuila and Durango, Mexico. The dome is a circular structure, similar to 16 km in diameter, that can be seen in airphotos, satellite images, and shaded relief maps, but that has a subtle topographic expression on the ground. As seen in the field, the most conspicuous topographic features in the area are several hills with the morphology of volcanic necks that rise up to 250 m above the surrounding terrain. The deformation fringe of the dome is a series of cuesta-like low hills, less than 30 m high, where a poorly lithified volcano-sedimentary succession (litharenites, polymictic conglomerates, and ignimbrites) is almost completely masked by desert pavement, which is mainly constituted by well-rounded calcareous clasts derived from the Mesozoic sedimentary marine rocks and by less abundant Paleogene volcanic rocks exposed in the region. Inside the dome the following units are exposed: 1) the pre-volcanic basement in a NW-trending, upright, open anticline developed in limestone of the Aurora Formation, 2) a series of hills where is exposed a succession of epiclastic and volcanic rocks, which are similar, in age and lithology, to some facies of the Ahuichila Formation, and 3) a NW-trending dike, exposed at Cerro Dinamita, which is interpreted as an offshoot of the buried subvolcanic body that created the dome. The deformation fringe around the buried intrusive has a quaquaversal array in the bedding and forms a simple monocline-like structure in the NE part of the dome. A set of SE- and NW-trending plunging folds forms the SE and SW portions of the dome, respectively. The NW part of the fringe is nearly completely masked by volcanic rocks, but there is a similar to W plunging syncline in the area. Geophysical data show a broad gravimetric high in the region, and there is a distinct aeromagnetic anomaly inside the dome. The morphological expression of the dome lies just east of a NW-trending lineament of gravity and magnetic anomalies, which may be the buried portion of a normal fault shown in geologic maps of the region northwest of the studied area. Another possible cause is an alignment of buried intrusive bodies suggested by the regional aeromagnetic data, a small diorite outcrop south of Sierra El Diablo, and presence of volcanic necks in the northern portion of Sierra Los Alamos. Available geological and geophysical information was used to model a near-surface, irregular intrusive body with variable magnetic susceptibilites. This variation in susceptibilities is consistent with observed differences in rock composition in the exposed volcanic rocks and with evidence that the structure was formed by a bimodal (andesite-rhyolite) magmatic system where mixing/mingling occurred. As a whole, the set of structures is interpreted as a dome formed by forceful magma injection into a previously folded Paleogene volcanosedimentary succession. U-Pb zircon ages were used to bracket the age of the deformation pulses registered in the rocks. Litharenites from the deformed volcano-sedimentary succession yielded an Ypresian zircon age of similar to 51 Ma. A tilted, lithic-rich ignimbritc collected near the top of the exposed volcano-sedimentary succession has mean age of 46.4(+0.8)/(-1.6) Ma, and the Cerro Dinamita dike has a mean age of 29.37 0.24 Ma. Thus, the youngest pulse of Laramide deformation in the area is younger than similar to 46 Ma and the re-folding, associated with emplacement of the dome occurred at similar to 29 Ma. Detrital zircon U-Pb ages from Mercurio sandstones suggest dominant sediment sources from plutonic and/or volcanic rocks exposed along western Mexico. Likely subordinate sources arc Mesozoic sedimentary rocks in northern and central Mexico. Distribution of detrital zircon U-Pb ages in the studied samples is similar to that documented in sandstones of the Difunta Group at the Parras and La Popa basins, except that older grains (>1.0 Ga), documented in the clastic rocks of these basins, are scarce in the sandstones of the Mercurio area.
英文关键词	structural dome forceful injection geophysical modeling magma mixing and mingling Ahuichila Formation Sierra Madre Occidental Coahuila Calcareous Platform Mexico
类型	Article
语种	英语
开放获取类型	gold
收录类别	SCI-E
WOS记录号	WOS:000510766200006
WOS关键词	LARAMIDE MAGMATIC ARC ; NORTH-CENTRAL SONORA ; U-PB GEOCHRONOLOGY ; SAN-MARCOS FAULT ; SOUTHERN BASIN ; TERTIARY MAGMATISM ; STRATIGRAPHY ; EXTENSION ; RANGE ; GEOCHEMISTRY
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
来源机构	Universidad Nacional Autónoma de México
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/369514
作者单位	[Jorge Aranda-Gomez, Jose; Ortega-Obregon, Carlos] Univ Nacl Autonoma Mexico, Ctr Geociencias, Campus Juriquilla, Queretaro 76230, Qro, Mexico; [Yutsis, Vsevolod; Ernesto Torres-Gaytan, David] Inst Potosino Invest Cient & Tecnol, Div Geociencias Aplicadas, San Luis Potosi, SLP, Mexico; [Juarez Arriaga, Edgar; Gonzalez-Cervantes, Norma] Univ Nacl Autonoma Mexico, Ctr Geociencias, Posgrad Ciencias Tierra, Queretaro, Qro, Mexico; [Chavez-Cabello, Gabriel; Francisco Ramirez-Pena, Cesar] Univ Autonoma Nuevo Leon, Fac Ciencias Tierra, Linares, NL, Mexico
推荐引用方式 GB/T 7714	Jorge Aranda-Gomez, Jose,Yutsis, Vsevolod,Juarez Arriaga, Edgar,et al. Reconnaissance geology and geophysics of the Mercurio structural dome, Chihuahua, Mexico[J]. Universidad Nacional Autónoma de México,2019,36(3):357-377.
APA	Jorge Aranda-Gomez, Jose.,Yutsis, Vsevolod.,Juarez Arriaga, Edgar.,Ortega-Obregon, Carlos.,Gonzalez-Cervantes, Norma.,...&Ernesto Torres-Gaytan, David.(2019).Reconnaissance geology and geophysics of the Mercurio structural dome, Chihuahua, Mexico.REVISTA MEXICANA DE CIENCIAS GEOLOGICAS,36(3),357-377.
MLA	Jorge Aranda-Gomez, Jose,et al."Reconnaissance geology and geophysics of the Mercurio structural dome, Chihuahua, Mexico".REVISTA MEXICANA DE CIENCIAS GEOLOGICAS 36.3(2019):357-377.