Geochemistry of Indian Ocean tephra and Afro-Arabian lavas

Widespread silicic pyroclastic eruptions of the Oligocene Afro-Arabian flood volcanic province (ignimbrites and airfall tuffs) produced up to 20% of the total flood volcanic stratigraphy (>6104 km3). Volumes of individual ignimbrites and tuffs exposed on land range from ~150 to >2000 km*3 and eight major units (15-100 m thick) were erupted in 500 km distant); and (b) to two deep sea ash layers sampled by ODP Leg 115 in the Indian Ocean ~2700 km to the southeast. This correlation is based on whole rock analyses of silicic units for isotope ratios (Pb, Nd) and rare earth element compositions, in conjunction with novel in situ Pb isotope laser ablation multicollector inductively coupled plasma mass spectroscopy analysis of groundmass and glass shards. Compositional diversity preserved on the scale of individual ash shards in these deep sea tephra layers record chemical heterogeneity present in the silicic magma chambers that is not evident in the welded on-land deposits. Ages of the ash layers can be established by correlation to precisely dated on-land ignimbrites, and current evidence suggests that while these eruptions may have exacerbated already changing climatic conditions, they both marginally post-date the Oi2 global cooling anomaly.

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Cite this as

Ukstins Peate, Ingrid, Baker, Joel A, Kent, Adam J R, Al-Kadasi, Mohamed, Al-Subbary, Abdulkarim, Ayalew, Dereje, Menzies, Martin (2003). Dataset: Geochemistry of Indian Ocean tephra and Afro-Arabian lavas. https://doi.org/10.1594/PANGAEA.722623

DOI retrieved: 2003

Additional Info

Field Value
Imported on November 29, 2024
Last update November 29, 2024
License CC-BY-3.0
Source https://doi.org/10.1594/PANGAEA.722623
Author Ukstins Peate, Ingrid
Given Name Ingrid
Family Name Ukstins Peate
More Authors
Baker, Joel A
Kent, Adam J R
Al-Kadasi, Mohamed
Al-Subbary, Abdulkarim
Ayalew, Dereje
Menzies, Martin
Source Creation 2003
Publication Year 2003
Resource Type application/zip - filename: Ukstins-Peate_2003
Subject Areas
Name: Geophysics

Related Identifiers
Title: Correlation of Indian Ocean tephra to individual Oligocene silicic eruptions from Afro-Arabian flood volcanism
Identifier: https://doi.org/10.1016/S0012-821X(03)00192-4
Type: DOI
Relation: IsSupplementTo
Year: 2003
Source: Earth and Planetary Science Letters
Authors: Ukstins Peate Ingrid , Baker Joel A , Kent Adam J R , Al-Kadasi Mohamed , Al-Subbary Abdulkarim , Ayalew Dereje , Menzies Martin .