Unravelling primary δ18O signatures of the 1730-36 Timanfaya parental magmas on Lanzarote
(2024) In Dissertations in Geology at Lund University GEOR02 20231Department of Geology
- Abstract
- Lanzarote is an island that is part of the intraplate ocean island volcanism that makes up the Canary archipelago. The Timanfaya eruption (1730-36) was a crucial event in the geological history of Lanzarote. It is considered an anomaly in the volcanic record of the archipelago due to its long eruptive activity, large volume of lava and composition (alkali basalts evolving into tholeiites). The origin of these late-stage tholeiites was interpreted in terms of two possible scenarios, i.e., partial melting of a mantle source or shallow level crustal contamination.
Through the use of petrographic and field observations, as well as chemical analyses of sedimentary xenoliths discovered in the late-stage tholeiites. This study sought to shed new... (More) - Lanzarote is an island that is part of the intraplate ocean island volcanism that makes up the Canary archipelago. The Timanfaya eruption (1730-36) was a crucial event in the geological history of Lanzarote. It is considered an anomaly in the volcanic record of the archipelago due to its long eruptive activity, large volume of lava and composition (alkali basalts evolving into tholeiites). The origin of these late-stage tholeiites was interpreted in terms of two possible scenarios, i.e., partial melting of a mantle source or shallow level crustal contamination.
Through the use of petrographic and field observations, as well as chemical analyses of sedimentary xenoliths discovered in the late-stage tholeiites. This study sought to shed new light on the relationship between the magma chamber and sedimentary crust in order to better understand the origin of the tholeiites.
The results showed that the late-stage tholeiites produced during the Timanfaya eruption were not a direct cause of contamination, as shallow-level contamination processes cannot be reconciled with the data. The tholeiites had a consistent low oxygen isotopic composition, indicating a mantle source signal, specifically a HIMU plume source beneath Lanzarote.
A high degree of melting of a lherzolite source may have contributed to the tholeiites, as evidenced by other studies. This theory is further supported by geophysical evidence of a low-velocity zone under the island. It's unclear exactly what is causing this melting and might be attributed to a local phenomenon.
The findings contribute to understanding the archipelago's geological history and the processes that have shaped its volcanic activity. This study highlights the role of melting in magma genesis and the potential for changes in mantle composition to influence volcanic eruptions. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9174165
- author
- Gleisner, Lovisa LU
- supervisor
- organization
- course
- GEOR02 20231
- year
- 2024
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Lanzarote, Timanfaya, Volcanology, Sedimentary xenoliths, Oxygen isotopes, Tholeiites, Petrography, Contamination, HIMU
- publication/series
- Dissertations in Geology at Lund University
- report number
- 697
- language
- English
- additional info
- External supervisor: Prof. Valentin R. Troll, Uppsala university
- id
- 9174165
- date added to LUP
- 2024-09-10 15:13:53
- date last changed
- 2024-09-10 15:13:53
@misc{9174165,
abstract = {{Lanzarote is an island that is part of the intraplate ocean island volcanism that makes up the Canary archipelago. The Timanfaya eruption (1730-36) was a crucial event in the geological history of Lanzarote. It is considered an anomaly in the volcanic record of the archipelago due to its long eruptive activity, large volume of lava and composition (alkali basalts evolving into tholeiites). The origin of these late-stage tholeiites was interpreted in terms of two possible scenarios, i.e., partial melting of a mantle source or shallow level crustal contamination.
Through the use of petrographic and field observations, as well as chemical analyses of sedimentary xenoliths discovered in the late-stage tholeiites. This study sought to shed new light on the relationship between the magma chamber and sedimentary crust in order to better understand the origin of the tholeiites.
The results showed that the late-stage tholeiites produced during the Timanfaya eruption were not a direct cause of contamination, as shallow-level contamination processes cannot be reconciled with the data. The tholeiites had a consistent low oxygen isotopic composition, indicating a mantle source signal, specifically a HIMU plume source beneath Lanzarote.
A high degree of melting of a lherzolite source may have contributed to the tholeiites, as evidenced by other studies. This theory is further supported by geophysical evidence of a low-velocity zone under the island. It's unclear exactly what is causing this melting and might be attributed to a local phenomenon.
The findings contribute to understanding the archipelago's geological history and the processes that have shaped its volcanic activity. This study highlights the role of melting in magma genesis and the potential for changes in mantle composition to influence volcanic eruptions.}},
author = {{Gleisner, Lovisa}},
language = {{eng}},
note = {{Student Paper}},
series = {{Dissertations in Geology at Lund University}},
title = {{Unravelling primary δ[18]O signatures of the 1730-36 Timanfaya parental magmas on Lanzarote}},
year = {{2024}},
}