MAPLES – MAgma PLays with sedimEntary rockS
With this project we aim at better understanding processes and scales of contamination between sills and sedimentary host-rocks of different lithologies. This is done by quantifying element exchanges, entrapments and escapes, from a within-sill perspective and by case studies.
Three case studies will allow defining how MAgma PLays with sEdimentary rockS of different lithologies. Field picture: S. Callegaro and L.E. Augland serve as scale in the picture. Photo: Ella W. Stokke
About the project
The intrusive parts of Large Igneous Provinces (LIPs) contribute enormously to the gas loads of such events on the atmosphere, with consequent climate forcing and associated mass extinctions. Large sill intrusions in LIPs interact with sedimentary host-rocks in volcanic basins and generate a number of gas species, released into the atmosphere by venting episodes.
Gas fluxes change profoundly when LIPs plumbing systems intrude volcanic basins with different dominant lithologies. Sill-driven contact metamorphism and consequent thermogenic gas release is well studied, much less so are the processes occurring within the magma bodies.
In the MAPLES project we seek to find answer to the question if sills are sinks or sources of volatiles and trace metals: ‘ MAPLES will improve our understanding of the interplay between sills and volatile-rich host-rocks occurring during LIPs emplacement, by a petrological and geochemical study of the igneous bodies.
‘ MAPLES will clarify the boundaries between melt-stage and sub-solidus processes of sill-host rock interaction occurring within the sills, defining new geochemical tracers to detect and quantify these interactions.
‘ MAPLES will provide crucial insights into the cycling of key elements and volatiles during periods when the Earth experienced rapid climatic changes and mass extinctions.
LIP-related severe forcing on the atmospheric gas budgets is the best analog for the changes mankind is causing on the atmosphere in the Anthropocene: understanding the past helps acting for the future.
Objectives
Overarching objective: Clarify processes and scales of contamination between sills and sedimentary host-rocks of different lithologies.
To do so, three types of host-rock lithologies and four case studies are addressed:
Obj.1 – Sills in evaporites and carbonates: detailing the fate of halogens and sulfur (Case: the Tunguska Basin - Siberia, RU),
Obj.2 – Sills in clastic lithologies: interplay with host-rocks injected as sediment dykes (Case: the Karoo Basin, South Africa),
Obj.3 – Sill-petroleum systems: open vs. closed system evolution and fate of trace metals (Case: the Oslo Rift – Norway; the Karoo Basin - South Africa), and
Obj.4 – Comparison among end-member scenarios.
Background
To achieve the objective of the project, a variety of cutting-edge in situ geochemical and petrological techniques will be applied (e.g. ion probe, synchrotron-light microfluorescence, micro-CT, LA-ICPMS, Raman, piston cylinder). Laboratories of Department of Geosciences – UiO/ (e.g. SEM, Electron microprobe, the CLIPT-Lab for stable isotopes) will be key analytical assets for the implementation of MAPLES. A field campaign in the Karoo Basin will also be carried out.
Financing
Full name of the project: MAgma PLays with sedimEntary rockS - Element exchange between magma, sedimentary host-rocks and environment
Source of financing: NFR, FRIPRO – Young Research Talents
Project number: 301096 (NFR) | 144995 (UiO)
Start: 15.08.2020. End: 15.01.2024.
Collaboration
MAPLES involves researchers from several institutions, and relies on the expertise of, and long-established collaboration with scientists from the Universities of Oslo, Uppsala (SE), Padova (IT) and McGill (CA). MAPLES may allow establishing of new, further collaborations.