The 1-atmosphere melting patterns of some basaltic volcanic series

Clicks: 3
ID: 299963
1972
Free PDF
Article Quality & Performance Metrics
Overall Quality
Not rated
Combines reader engagement with the AI quality analysis. This article has not been analysed, so there is no overall score — reader engagement is measured and shown alongside.
AI Quality Assessment
Not analyzed
Readership in this journal
Emerging

Ranked #7,080 of 8,486 articles by views in american journal of science

Most read Least read

Bar heights use a square-root scale. Only the 120 most-read articles are drawn; the journal has 8,486 in total.

Mint this article as an NFT
Not yet minted

Create a permanent, verifiable on-chain record of this article on the Scimatic Network. The NFT is held in your Journament account, and you can withdraw it to your own wallet at any time.

5 SUSD one-off · no wallet required
Sign in to mint
Abstract
The results of 1-atm melting experiments on suites of lavas from Kilauea (Hawaii), Snake River Plain (Idaho), Reunion and Anjouan (Indian Ocean), and Skye (Scotland) are summarized. The patterns formed by plotting the melting stages of each lava in a series against its iron:magnesium ratio are compared with a simple synthetic model, derived from the system MgO-FeO-SiO, at 1 atm. Although there is close agreement between the magnesian parts of the natural patterns and the synthetic model, this relationship does not extend the fusion behavior of the more iron-rich lavas. The deviations of their 1-atm thermal behavior from both the model and their observed phenocryst mineralogy are ascribed to the effects of load pressure and rising PH ~2~ O during the evolution of the magma series. Comparison of the deduced fractionation histories of the natural suites with currently used models for basalt crystallization shows some notable discrepancies, especially with iron- and alkali-free models based on the system CaO-MgO-Al ~2~ O ~3~ -SiO ~2~ and its subsystems. It is shown that by limiting the basalt composition field to rocks containing a normative plagioclase more calcic than An50 most of the iron-rich lavas forming \"anomalous\" melting patterns are at the margin of the basalt composition field or slightly outside it. However, if the same criterion is applied equally carefully to the equilibria in published models for basalt crystallization, it appears probable that parts of the low-temperature, low-variance regions of these models are in fact constructed from and relevant to the crystallization behavior of intermediate lavas, not basalts. Available 1-atm melting data on magnesian aphanites and natural glasses from widely dispersed areas suggest that the maximum temperatures of eruption of basaltic liquids are 1220 degrees to 1240 degrees C. The basalt-intermediate lava transition takes place at 1160 degrees to 1190 degrees C at 1 atm in the lava suites considered here. Magnetite joins the liquidus phases at approximately 1170 degrees and 1190 degrees C in the alkalic lavas of Anjouan and Skye, respectively. Anomalies attributed to PH ~2~ O in the magmas occur in the melting patterns of both tholeiitic and alkalic series up to approximately 1190 degrees C. These thermal data place considerable restrictions on any approach to basalt crystallization that does not include alkalies, iron, and water as components in its model.
Reference Key
openalex_W2319529295 Use this key to autocite in the manuscript while using SciMatic Manuscript Manager or Thesis Manager
Authors R. N. Thompson
Journal american journal of science
Year 1972
DOI
10.2475/ajs.272.10.901
URL
https://ajs.scholasticahq.com/article/59512.pdf
Keywords Keywords not found

Citations

No citations found. To add a citation, contact the admin at info@scimatic.org

Comments

No comments yet. Be the first to comment on this article.