Gravity and aeromagnetic constraints on the structure of the Woods Mountains volcanic center, southeastern California |
| |
| Authors: | Kevin L Mickus Micheal McCurry |
| |
| Institution: | (1) Department of Geosciences, Southwest Missouri State University, Springfield, MO 65804, USA, US;(2) Department of Geology, Idaho State University, Pocatello, ID 83209, USA, US |
| |
| Abstract: | The Woods Mountain volcanic center is a well-exposed, mildly alkaline volcanic center that formed during the Miocene in southeastern
California. Detailed geologic mapping and geochemical studies have distinguished three major volcanic phases: precaldera,
caldera forming, and postcaldera. Geologic mapping indicates that caldera formation occurred incrementally during eruptions
of three large ignimbrites and continued into a period of voluminous intracaldera lava-flow eruptions. Rhyolitic ignimbrites
and lava flows within the caldera are associated with large amplitude, circular gravity, and magnetic minima that are among
the most prominent gravity and magnetic anomalies in southeastern California. Analysis of a Bouguer gravity anomaly map, reduced-to-the-pole
magnetic intensity map, and three-dimensional gravity and magnetic models indicates that there is a single, funnel- to bowl-shaped
caldera approximately 4 km thick and approximately 10 km wide at the surface. This model is consistent with other siliceous,
pyroclastic-filled calderas on continental crust, except that most siliceous volcanic centers associated with more than one
eruption are characterized by more than one caldera.
Received: 20 December 1997 / Accepted: 15 October 1998 |
| |
| Keywords: | Gravity anomalies Magnetic anomalies Caldera Ignimbrites |
| 本文献已被 SpringerLink 等数据库收录！ |
|
