01whole.pdf (5.21 MB)
Download file

Mineralogical and geochemical constraints on magmatic evolution at Tengger caldera, Indonesia

Download (5.21 MB)
thesis
posted on 28.03.2022, 22:30 by John Wardell
A detailed mineralogical and geochemical study was carried out on stratigraphically wellconstrained samples at Tengger Caldera Volcanic Complex (TCVC) to investigate the petrological and geochemical evolution of Tengger Caldera and the genetic relationship of the post-caldera volcanic cones to the pre-caldera magmatic system. The TCVC deposits are separated into the pre-caldera, caldera-forming and post-caldera eruptive episodes that span 820,000 years. These deposits range in composition from basalt, basaltic andesite to trachyandesite and are tholeiitic to calc-alkaline in nature. The volcanic rocks define two geochemical groups based on major and trace element compositions: a low silica group and high silica group, with the initial caldera-forming eruption sequence characterised by low silica content. The post-caldera centres of Batok and Bromo show affinity to the low silica and high silica groups, respectively. Bromo rocks contain a more restricted range in plagioclase composition, towards lower An content compared to Batok. Bromo samples contain phenocrysts of pigeonite, which is absent elsewhere in the system. Thermobarometry estimates of crystallisation temperatures and pressures reveal two storage regions beneath the caldera: a shallow region at 7 to 11 km and a deeper region at 19 to 27 km. Magma feeding Bromo shows relativity deeper storage compared to that at Batok.

History

Table of Contents

1. Introduction -- 2. Approach and analytical methods -- 3. Results -- 4. Discussion -- 5. Conclusions and future work.

Notes

Theoretical thesis. Bibliography: pages 51-55

Awarding Institution

Macquarie University

Degree Type

Thesis MRes

Degree

MRes, Macquarie University, Faculty of Science and Engineering, Department of Earth and Planetary Sciences

Department, Centre or School

Department of Earth and Planetary Sciences

Year of Award

2018

Principal Supervisor

Heather Handley

Additional Supervisor 1

Simon Turner

Rights

Copyright John Wardell 2018. Copyright disclaimer: http://mq.edu.au/library/copyright

Language

English

Jurisdiction

Indonesia

Extent

1 online resource (vi, 61 pages : illustrations, maps)

Former Identifiers

mq:71027 http://hdl.handle.net/1959.14/1270106