Document
Journal of Volcanology and Geothermal Research
Generically Dependent Continuant
RDF description of Origin and formation of neck in a basin landform: Examples from the Camargo volcanic field, Chihuahua (México) - http://orbis.uaslp.mx/vivo/individual/scopus2592
Erosional basin; Volcanic landform; Volcanic neck Basaltic lava; Basaltic lava flow; Basaltic scoria; Drainage patterns; Erosional basin; Eruptive activity; Fault scarp; Fluvial erosion; Head waters; High rate; Key factors; Lava flows; Miocene; Neck-in; Pliocene; Pyroclastic deposits; Scoria cone; Sheet-like; Small streams; Steep walls; Volcanic field; Volcanic landform; Volcanic neck; Volcanic structures; Basalt; Deposits; Erosion; Geomorphology; Levees; Volcanoes; basalt; basin evolution; erosion; intraplate process; lava flow; volcanic eruption; volcanic landform; volcanogenic deposit; Chihuahua; Mexico [North America]
The term neck in a basin (NIB) landform is proposed for volcanic structures characterized by nearly circular to elliptical open basins, located near the headwater of small streams or drainages, which contain small volcanic necks and/or erosion remnants of one (or more) cinder cones. NIB landforms are typically 400-1000. m in diameter and 30-100. m deep and are invariably surrounded by steep walls cut into one or more basaltic lava flows. NIB landforms lack evidence for a primary volcanogenic origin through either collapse or youthful eruptive activity. In the Pliocene portion (4 - 2. Ma) of the Plio-Quaternary Camargo volcanic field of Chihuahua (México), they are relatively numerous and are best developed at the margins of a gently sloping (3-5°) basaltic lava plateau and near major fault scarps. Mature NIB landforms have ring-like circular drainage patterns and central elevations marked by small volcanic necks and associated radial dikes intruded into basaltic scoria-fall and /or agglutinate deposits. We interpret NIB landforms to be erosional in origin. They develop where a cinder cone is surrounded by one or more sheet-like lava flows from one or more separate subsequent vents. Once eruptive activity ceases at the younger volcano(es), fluvial erosion gradually produces a ring-like drainage pattern along the contact between the lava and the older cinder cone. As a response to a marked contrast in resistance to erosion between lava flows and unconsolidated or poorly lithified pyroclastic deposits, the older cinder cone is preferentially eroded. In this manner, a ring-shaped, steep sided erosional basin, preformed by the scoria cone, is produced; eventually fluvial erosion exposes the central neck and dikes. The volume, relief, and age of the volcanic field are key factors in the formation and preservation of a NIB landform. They form in volcanic fields where lava emissions are sufficiently vigorous to engulf earlier cinder cones. Relief and associated high rates of fluvial erosion play an important role in NIB development, as demonstrated by their locations in the Camargo volcanic field. Fully developed NIB landforms are not found in Quaternary volcanic fields, probably because erosion has not had sufficient time to generate their characteristics features. NIB landforms are also absent in Miocene fields, because erosion has proceeded too far, and thus has completely removed any NIB landform that may once have existed. The Camargo volcanic field is the only major area of Pliocene intraplate eruptive activity in northern México, and the only place where NIB landforms are relatively abundant. © 2009 Elsevier B.V.
Origin and formation of neck in a basin landform: Examples from the Camargo volcanic field, Chihuahua (México)
Article
Information Content Entity