View in EDS

Magnetotelluric investigations at Andean volcanoes: Partial melt or saline magmatic fluids?

Saved in:
Bibliographic Details
Title: Magnetotelluric investigations at Andean volcanoes: Partial melt or saline magmatic fluids?
Authors: Jenkins, A.P.1 (AUTHOR) alexander.jenkins@bristol.ac.uk, Rust, A.C.1 (AUTHOR), Blundy, J.2 (AUTHOR), Biggs, J.1 (AUTHOR)
Source: Journal of Volcanology & Geothermal Research. Aug2023, Vol. 440, pN.PAG-N.PAG. 1p.
Subjects: Volcanic hazard analysis, Volcanoes, Magnetotelluric prospecting, Electric conductivity, Geothermal resources, Metallogeny
Abstract: Knowledge of the architecture of active magmatic systems is important for both volcanic hazard assessment and evaluating potential geothermal energy production and metals recovery from magmatic fluids. Increasingly, magmatic systems are imaged using the magnetotelluric method to detect electrically conductive partial melt and/or saline magmatic fluid reservoirs. We review recent magnetotelluric studies at eight Andean volcanoes, revealing electrical conductivity anomalies with variable magnitudes and locations. Six of the studied volcanoes exhibit three main electrical conductivity anomalies, located at shallow (< 3 km), intermediate (≈ 5 km), and deep (> 10 km) depths. The shallow anomalies are often thin and laterally extensive, consistent with clay cap alteration layers, while the deep anomalies are generally interpreted as partial melt reservoirs. The intermediate depth anomalies, although also often attributed to partial melt, have less clear origins. By analysing laboratory-derived electrical conductivity relationships, we show that the intermediate depth anomalies are generally most consistent with saline magmatic fluids stored in porous rock. However, other geophysical and petrological data suggest that localised partial melt also exists at intermediate depths. Therefore, the intermediate depth anomalies likely represent mixed melt and saline magmatic fluid systems, such as those responsible for forming magmatic-hydrothermal alteration zones and copper porphyry deposits. At individual volcanoes, refining the generalised three layer model proposed here by using additional geophysical or petrological data is key to constraining the resources and/or hazard potential of the magmatic system. • Magnetotelluric studies at Andean volcanoes suggest a general three layer structure. • This comprises a deep (> 10 km) melt reservoir and shallow (< 3 km) clay alteration. • At intermediate depths (≈5 km), melt and saline fluids likely coexist. • Some intermediate depth anomalies may represent actively forming copper porphyries. [ABSTRACT FROM AUTHOR]
Copyright of Journal of Volcanology & Geothermal Research is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
FullText Text:
  Availability: 0
Header DbId: egs
DbLabel: Engineering Source
An: 169787361
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Magnetotelluric investigations at Andean volcanoes: Partial melt or saline magmatic fluids?
– Name: Author
  Label: Authors
  Group: Au
  Data: &lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Jenkins%2C+A%2EP%2E%22&quot;&gt;Jenkins, A.P.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt; (AUTHOR)&lt;i&gt; alexander.jenkins@bristol.ac.uk&lt;/i&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Rust%2C+A%2EC%2E%22&quot;&gt;Rust, A.C.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt; (AUTHOR)&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Blundy%2C+J%2E%22&quot;&gt;Blundy, J.&lt;/searchLink&gt;&lt;relatesTo&gt;2&lt;/relatesTo&gt; (AUTHOR)&lt;br /&gt;&lt;searchLink fieldCode=&quot;AR&quot; term=&quot;%22Biggs%2C+J%2E%22&quot;&gt;Biggs, J.&lt;/searchLink&gt;&lt;relatesTo&gt;1&lt;/relatesTo&gt; (AUTHOR)
– Name: TitleSource
  Label: Source
  Group: Src
  Data: &lt;searchLink fieldCode=&quot;JN&quot; term=&quot;%22Journal+of+Volcanology+%26+Geothermal+Research%22&quot;&gt;Journal of Volcanology &amp; Geothermal Research&lt;/searchLink&gt;. Aug2023, Vol. 440, pN.PAG-N.PAG. 1p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: &lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Volcanic+hazard+analysis%22&quot;&gt;Volcanic hazard analysis&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Volcanoes%22&quot;&gt;Volcanoes&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Magnetotelluric+prospecting%22&quot;&gt;Magnetotelluric prospecting&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Electric+conductivity%22&quot;&gt;Electric conductivity&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Geothermal+resources%22&quot;&gt;Geothermal resources&lt;/searchLink&gt;&lt;br /&gt;&lt;searchLink fieldCode=&quot;DE&quot; term=&quot;%22Metallogeny%22&quot;&gt;Metallogeny&lt;/searchLink&gt;
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: Knowledge of the architecture of active magmatic systems is important for both volcanic hazard assessment and evaluating potential geothermal energy production and metals recovery from magmatic fluids. Increasingly, magmatic systems are imaged using the magnetotelluric method to detect electrically conductive partial melt and/or saline magmatic fluid reservoirs. We review recent magnetotelluric studies at eight Andean volcanoes, revealing electrical conductivity anomalies with variable magnitudes and locations. Six of the studied volcanoes exhibit three main electrical conductivity anomalies, located at shallow (&lt; 3 km), intermediate (≈ 5 km), and deep (&gt; 10 km) depths. The shallow anomalies are often thin and laterally extensive, consistent with clay cap alteration layers, while the deep anomalies are generally interpreted as partial melt reservoirs. The intermediate depth anomalies, although also often attributed to partial melt, have less clear origins. By analysing laboratory-derived electrical conductivity relationships, we show that the intermediate depth anomalies are generally most consistent with saline magmatic fluids stored in porous rock. However, other geophysical and petrological data suggest that localised partial melt also exists at intermediate depths. Therefore, the intermediate depth anomalies likely represent mixed melt and saline magmatic fluid systems, such as those responsible for forming magmatic-hydrothermal alteration zones and copper porphyry deposits. At individual volcanoes, refining the generalised three layer model proposed here by using additional geophysical or petrological data is key to constraining the resources and/or hazard potential of the magmatic system. • Magnetotelluric studies at Andean volcanoes suggest a general three layer structure. • This comprises a deep (&gt; 10 km) melt reservoir and shallow (&lt; 3 km) clay alteration. • At intermediate depths (≈5 km), melt and saline fluids likely coexist. • Some intermediate depth anomalies may represent actively forming copper porphyries. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: &lt;i&gt;Copyright of Journal of Volcanology &amp; Geothermal Research is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder&#39;s express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.&lt;/i&gt; (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=169787361
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1016/j.jvolgeores.2023.107852
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 1
        StartPage: N.PAG
    Subjects:
      – SubjectFull: Volcanic hazard analysis
        Type: general
      – SubjectFull: Volcanoes
        Type: general
      – SubjectFull: Magnetotelluric prospecting
        Type: general
      – SubjectFull: Electric conductivity
        Type: general
      – SubjectFull: Geothermal resources
        Type: general
      – SubjectFull: Metallogeny
        Type: general
    Titles:
      – TitleFull: Magnetotelluric investigations at Andean volcanoes: Partial melt or saline magmatic fluids?
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Jenkins, A.P.
      – PersonEntity:
          Name:
            NameFull: Rust, A.C.
      – PersonEntity:
          Name:
            NameFull: Blundy, J.
      – PersonEntity:
          Name:
            NameFull: Biggs, J.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 08
              Text: Aug2023
              Type: published
              Y: 2023
          Identifiers:
            – Type: issn-print
              Value: 03770273
          Numbering:
            – Type: volume
              Value: 440
          Titles:
            – TitleFull: Journal of Volcanology & Geothermal Research
              Type: main
ResultId 1