Skip to Main Content
Book Chapter

Geology and geochemistry of Late Quaternary volcanism in northern Harrat Rahat, Kingdom of Saudi Arabia: implications for eruption dynamics, regional stratigraphy and magma evolution

By
H. Murcia
H. Murcia
School of Environment, University of Auckland, Auckland, New ZealandDepartment of Geological Sciences, Instituto de Investigaciones en Estratigrafía (IIES), Universidad de Caldas, Manizales, Colombia
Search for other works by this author on:
J. M. Lindsay
J. M. Lindsay
School of Environment, University of Auckland, Auckland, New Zealand
Search for other works by this author on:
K. Németh
K. Németh
Volcanic Risk Solutions, Massey University, Palmerston North, New Zealand
Search for other works by this author on:
I. E. M. Smith
I. E. M. Smith
School of Environment, University of Auckland, Auckland, New Zealand
Search for other works by this author on:
S. J. Cronin
S. J. Cronin
School of Environment, University of Auckland, Auckland, New Zealand
Search for other works by this author on:
M. R. H. Moufti
M. R. H. Moufti
Geohazards Research Centre, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
Search for other works by this author on:
N. N. El-Masry
N. N. El-Masry
Geohazards Research Centre, King Abdulaziz University, Jeddah, Kingdom of Saudi ArabiaGeology Department, Faculty of Science, Suez Canal University, Ismailia, Egypt
Search for other works by this author on:
S. Niedermann
S. Niedermann
Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany
Search for other works by this author on:
Published:
January 01, 2017

Abstract

Harrat Rahat (<10 Ma) is one of the largest volcanic fields on western Arabia. In the north of the field, some of the youngest volcanic centres evolved through either point-like, complex or multiple aligned vents (i.e. along fissures), and have pyroclastic cones, lapilli fall deposits and/or lava flows associated with them. The products reflect dominantly Hawaiian eruptions, and only one centre experienced phreatomagmatism. Results from new 3He surface-exposure dating provide constraints on stratigraphy of the youngest (<0.3 Ma) products.

The rocks are compositionally alkali-basalt and hawaiite, with intra-plate basalt (prevalent mantle (PREMA)) affinity. Each eruption displays a distinct whole-rock composition in an overall linear trend. We suggest that the magma source for each centre is similar, and that composition of the products is different due to different degrees of fractionation. In a single eruption, the magma that reaches the surface first is the least evolved, with the most evolved magma erupting last. We also found that the most primitive magmas erupt less explosively. We think that the degree of magma evolution might correlate with ascent times, assuming that the more evolved magma spent more time en route. We suggest that magma ascent time is likely to be longer than that of other more primitive intra-plate basalts.

Supplementary material: Whole-rock chemistry results, mineral chemistry results and fractional crystallization modeling data are available at https://doi.org/10.6084/m9.figshare.c.3488988

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

Monogenetic Volcanism

K. Németh
K. Németh
Search for other works by this author on:
G. Carrasco-Núñez
G. Carrasco-Núñez
Search for other works by this author on:
J. J. Aranda-Gómez
J. J. Aranda-Gómez
Search for other works by this author on:
I. E. M. Smith
I. E. M. Smith
Search for other works by this author on:
The Geological Society of London
Volume
446
ISBN electronic:
978-1-78620-376-2
Publication date:
January 01, 2017

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal