NDLI: Generation of CO2-rich melts during basalt magma ascent and degassing

Content Provider	Springer Nature Link
Author	Pichavant, Michel Carlo, Ida Rotolo, Silvio G. Scaillet, Bru Burgisser, Alain Gall, lwenn Martel, Caroline
Copyright Year	2013
Abstract	To test mechanisms of basaltic magma degassing, continuous decompressions of volatile-bearing (2.7–3.8 wt% H2O, 600–1,300 ppm CO2) Stromboli melts were performed from 250–200 to 50–25 MPa at 1,180–1,140 °C. Ascent rates were varied from 0.25 to ~1.5 m/s. Glasses after decompression show a wide range of textures, from totally bubble-free to bubble-rich, the latter with bubble number densities from 104 to 106 cm−3, similar to Stromboli pumices. Vesicularities range from 0 to ~20 vol%. Final melt H2O concentrations are homogeneous and always close to solubilities. In contrast, the rate of vesiculation controls the final melt CO2 concentration. High vesicularity charges have glass CO2 concentrations that follow theoretical equilibrium degassing paths, whereas glasses from low vesicularity charges show marked deviations from equilibrium, with CO2 concentrations up to one order of magnitude higher than solubilities. FTIR profiles and maps reveal glass CO2 concentration gradients near the gas–melt interface. Our results stress the importance of bubble nucleation and growth, and of volatile diffusivities, for basaltic melt degassing. Two characteristic distances, the gas interface distance (distance either between bubbles or to gas–melt interfaces) and the volatile diffusion distance, control the degassing process. Melts containing numerous and large bubbles have gas interface distances shorter than volatile diffusion distances, and degassing proceeds by equilibrium partitioning of CO2 and H2O between melt and gas bubbles. For melts where either bubble nucleation is inhibited or bubble growth is limited, gas interface distances are longer than volatile diffusion distances. Degassing proceeds by diffusive volatile transfer at the gas–melt interface and is kinetically limited by the diffusivities of volatiles in the melt. Our experiments show that CO2-oversaturated melts can be generated as a result of magma decompression. They provide a new explanation for the occurrence of CO2-rich natural basaltic glasses and open new perspectives for understanding explosive basaltic volcanism.
Starting Page	545
Ending Page	561
Page Count	17
File Format	PDF
ISSN	00107999
Journal	Contributions to Mineralogy and Petrology
Volume Number	166
Issue Number	2
e-ISSN	14320967
Language	English
Publisher	Springer Berlin Heidelberg
Publisher Date	2013-06-21
Publisher Place	Berlin/Heidelberg
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Basaltic melts Volatiles Decompression experiments Magma degassing CO2-oversaturation Explosive volcanism Geology Mineral Resources Mineralogy
Content Type	Text
Resource Type	Article
Subject	Geochemistry and Petrology Geophysics

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Generation of CO2-rich melts during basalt magma ascent and degassing

Origin and ascent history of unusually crystal-rich alkaline basaltic magmas from the western Pannonian Basin

Shallow-level decompression crystallisation and deep magma supply at Shiveluch Volcano

Abrupt transitions during sustained explosive eruptions: examples from the 1912 eruption of Novarupta, Alaska

Plagioclase nucleation and growth kinetics in a hydrous basaltic melt by decompression experiments

The speciation of carbon dioxide in silicate melts

In situ observations of bubble growth in basaltic, andesitic and rhyodacitic melts

Time evolution of chemical exchanges during mixing of rhyolitic and basaltic melts

Explosive style, magma degassing and evolution in the Chaimilla eruption, Villarrica volcano, Southern Andes

Generation of CO2-rich melts during basalt magma ascent and degassing

Similar Documents

Generation of CO2-rich melts during basalt magma ascent and degassing

Origin and ascent history of unusually crystal-rich alkaline basaltic magmas from the western Pannonian Basin

Shallow-level decompression crystallisation and deep magma supply at Shiveluch Volcano

Abrupt transitions during sustained explosive eruptions: examples from the 1912 eruption of Novarupta, Alaska

Plagioclase nucleation and growth kinetics in a hydrous basaltic melt by decompression experiments

The speciation of carbon dioxide in silicate melts

In situ observations of bubble growth in basaltic, andesitic and rhyodacitic melts

Time evolution of chemical exchanges during mixing of rhyolitic and basaltic melts

Explosive style, magma degassing and evolution in the Chaimilla eruption, Villarrica volcano, Southern Andes

Generation of CO2-rich melts during basalt magma ascent and degassing