Three‐dimensional electrical resistivity model of the hydrothermal system in Long Valley Caldera, California, from magnetotellurics

Abstract Though shallow flow of hydrothermal fluids in Long Valley Caldera, California, has been well studied, neither the hydrothermal source reservoir nor heat source has been well characterized. Here a grid of magnetotelluric data were collected around the Long Valley volcanic system and modeled...

Full description

Saved in:
Bibliographic Details
Main Authors: J. R. Peacock, M. T. Mangan, D. McPhee, P. E. Wannamaker
Format: Article
Language:English
Published: Wiley 2016-08-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1002/2016GL069263
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Though shallow flow of hydrothermal fluids in Long Valley Caldera, California, has been well studied, neither the hydrothermal source reservoir nor heat source has been well characterized. Here a grid of magnetotelluric data were collected around the Long Valley volcanic system and modeled in 3‐D. The preferred electrical resistivity model suggests that the source reservoir is a narrow east‐west elongated body 4 km below the west moat. The heat source could be a zone of 2–5% partial melt 8 km below Deer Mountain. Additionally, a collection of hypersaline fluids, not connected to the shallow hydrothermal system, is found 3 km below the medial graben, which could originate from a zone of 5–10% partial melt 8 km below the south moat. Below Mammoth Mountain is a 3 km thick isolated body containing fluids and gases originating from an 8 km deep zone of 5–10% basaltic partial melt.
ISSN:0094-8276
1944-8007