Studying quartz behavior in (ultra)high-pressure metamorphic rocks: common mineral with underappreciated potential

This project aims to advance our understanding of the behavior of SiO2 minerals in subduction zones using a novel and multidisciplinary approach. The study involves combining analytical and experimental tools, including electron and ion microprobes, Raman spectroscopy, electron backscatter diffraction (EBSD), and acoustic microscopy applied to natural and experimental samples. We will run HP experiments to redefine the quartz-coesite phase transition filling the existing P-T gaps in an experimental survey of this phase boundary as well as to better understand the back reaction of coesite to quartz. We aim to formulate a new geothermobarometric technique based solely on investigating the phenomenon of acoustic impedance in minerals. We will characterize SiO2 polymorphs using EBSD and apply QuiG-TiQ  geothermobarometers to pre-selected (U)HP metamorphic rocks from several well described type-localities and experimental material. Hence, this project will substantially broaden our knowledge about the HP behavior of one of the most common constituents of the Earth’s lithosphere, namely crystalline SiO2. In turn, this newly gained knowledge will allow for easier recognition of rocks that were subjected to (U)HP metamorphism and contribute to ongoing debates on deep subduction of the continental crust. It will provide new, quantitative constraints on deeply buried crust exhumation mechanisms and rates. The obtained results can serve as a discriminant for validating the available exhumation models of deeply subducted continental crust. By completing the proposed research efforts, we should develop new thermobarometrical technique based on acoustic impedance.

2022-2025 National Science Centre Poland, Project Sonata no 2021/43/D/ST10/02305 – PI Karolina Kośmińska

Tectonic evolution of oceanic terranes in Iapetus: A petrochronological approach in the Northern Swedish Caledonides

This study investigates the mineral chemistry, petrology and inclusion mineralogy of different types of eclogite from the This project aims to investigate the metamorphic and tectonic evolution of the outboard terranes within the Neoproterozoic to Palaeozoic Iapetus Ocean, which today are exposed in the rocks of the Koli Nappe Complex within the Scandinavian Caledonides. The focus of the study will be the North Swedish Caledonides, in particular the Padjelanta region of Norrbotten. Detailed field investigations in this area will be followed by combined mineral-chemical and isotopic analyses of the acquired samples. P-T conditions of successive fabric generations will be quantified and combined with the application of petrochronological techniques to determine the absolute timing of metamorphic and deformational episodes. The subsequent increased understanding of the tectonic and thermal history of the region hope to make a valuable contribution towards developing tectonic models of the Caledonian Orogenic Belt, and thus will provide insights into the evolution of oceanic terranes within orogenic belts globally.

2022-2024 National Science Centre Poland, Project Preludium no 2021/41/N/ST10/04298 – PI Isabel Carter

Advancing in-situ white mica 40Ar/39Ar and Rb-Sr geochronology as tools to resolve tectonic processes

This study investigates the mineral chemistry, petrology and inclusion mineralogy of different types of eclogite from the This project aims to investigate the metamorphic and tectonic evolution of the outboard terranes within the Neoproterozoic to Palaeozoic Iapetus Ocean, which today are exposed in the rocks of the Koli Nappe Complex within the ScWhite mica is ubiquitous in metamorphic rocks and often defines rock structure. Tectonic histories of rocks within crustal depths can be exploited using white mica 40Ar/39Ar and Rb-Sr geochronological techniques. This project aims to utilize these techniques on white mica in situ to advance the understanding of how these geochronological systems comparatively respond to cooling, metamorphism, deformation, fluids, and intrinsic rock characteristics. Carefully designed case studies are being developed and tested using rocks from two natural laboratories: 1) the Seve Nappe Complex in the Scandinavian Caledonides; and 2) the Cycladic Blueschist Unit in the Greek Hellenides. The results of this project will promote the functionality of in-situ white mica 40Ar/39Ar and Rb-Sr geochronology and demonstrate how to apply these techniques to rocks in complex tectonic settings.

2021-2024 National Science Centre Poland, Project Sonatina no 2021/40/C/ST10/00264 – PI Christopher J. Barnes

UHP obliterated? The evolution of eclogite in and in between UHP areas, W Norway

This study investigates the mineral chemistry, petrology and inclusion mineralogy of different types of eclogite from the Western Gneiss Region (WGR), Norway in a spatial context. WGR eclogites typically occur in and in between areas of ultra-high pressure (UHP) metamorphism, which leads to ambiguity on the mechanisms applicable to have exhumed the high grade rocks. New data is expected to constrain (1) the metamorphic and spatial extents to which UHP and HP eclogites have a shared evolution, (2) if HP eclogites differ among each other depending on its occurrence within or in between UHP areas and (3) the preconditions required for the preservation of UHP eclogite. The working hypothesis is that many HP eclogites may have lost its former UHP metamorphic record. This project intends to localise the areas in which eclogites were most affected by retrogression.

2021-2023 Norway Grants operated by National Science Centre, Poland, project POLS no 2020/37/K/ST10/02784 – PI D. Spengler

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The timing of Iapetus opening and its implications for understanding the break-up of Rodinia and evolution of Baltica

It is widely accepted that the Iapetus Ocean opened in the latest Neoproterozoic, but the exact timing of this event is still debated. Nearly all evidence for such timing and reasoning about it are based on geochronological data obtained from mafic igneous rocks and their contact aureoles. However, the question arises whether the timing of this voluminous igneous activity is indeed representative for true opening of the Iapetus. If so, do we have a stratigraphic record of this event? Even more importantly, what was the role and where was located the centre of the mantle plume that was supposed to contribute to the Iapetus opening process ? To answer these questions, we propose to focus on the Neoproterozoic to Cambrian evolution of Baltica and possible peri-Baltican terranes.

2020-2023 National Science Centre, Poland, project Opus no 2019/33/B/ST10/01728 – PI J.Majka

High-pressure brittle failure of Tsäkkok eclogites (Scandinavian Caledonides) – interplay between dehydration and subduction zone seismicity

In this project, we study eclogites from the Tsäkkok Tectonic Lens (TTL) located above an Arctic Circle in Norrbotten, Sweden. The TTL represents a pre-Caledonian volcano-sedimentary succession that was buried at an exceptionally cold subduction zone prior to the final collision, metamorphosed and dehydrated at eclogite-facies conditions. The project employs a multimethod approach in order to (1) characterize microstructures that form during continuous and/or periodic fluid release events at high-pressure conditions and (2) constrain a distribution and composition, as well as the geochemical signature of released fluids. All in all, collected data will be compared to seismological observables to evaluate if the reconstructed mechanisms and fluid-release events match the seismic record in active subduction zones.

2020-2021 National Science Centre, Poland, project Preludium no 2019/33/N/ST10/01479 – PI M.Bukała

From deep subduction to the Earth’s surface: a thermochronological study of the allochthonous and parautochthonous units from the central Scandinavian Caledonides

In this project, we try to understand how and when the deeply subducted, HP-UHP allochthonous units have been exhumed to crustal levels and juxtaposed with the underlying lower grade nappes. The thermochronological data will serve as a reference for validating available models of exhumation of deeply subducted continental crust.
There are two main aims of the project: (1) to derive the very first comprehensive thermochronological data set for the high- and ultra-high pressure (HP-UHP) lithologies of the Middle Allochthon cropping out in the Swedish part of the Scandinavian Caledonides; and (2) to define the character and age of the deformation in the basement of Baltica and its relationship to the thrust tectonics in the nappes above.

2018-2022 National Science Centre, Poland, project Opus no 2018/29/B/ST10/02315 – PI I.Klonowska

Caledonian subduction along the Baltoscandian margin (CALSUB)

This project focuses on the subduction history of the Baltoscnadian margin of the continent Baltica and, in particular on the continent-arc collision that occurred in the Ordovician during closure of the Iapetus Ocean, prior to Baltica-Laurentia collision. This long process of ocean-closure may have involved a sequence of subduction-eduction events.
The overall goal is to get a broad understanding of the complexity of long-lasting collisional orogeny and apply this knowledge to the other such orogens, including Himalaya-Tibet.

2016-2021 National Science Centre, Poland, project SonataBis no 2014/14/E/ST10/00321 – PI J.Majka

Neoproterozoic Arctic Connection (NAC): is southwestern Svalbard a counterpart to the Pearya Terrane?

The overall goal of this project is to define a comprehensive model for the tectonothermal evolution of Caledonian basement in southwestern Svalbard that can be reliably compared with that of Pearya. However, the current state of knowledge about the basement of southwestern Svalbard is not sufficient to formulate conclusive arguments for its similarity, or dissimilarity, to the Pearya Terrane, or any other area in the Arctic. Several crucial petrological, geochronological and structural data are still lacking from southwestern Svalbard. Obtaining new data from southwestern Svalbard will allow for correlation of various local basement units that have been so far studied in isolation. Integrated interpretation and characterization of diagnostic features will lead to a coherent tectonic evolution model for the region and, allow for a test of existing and development of new trans-Arctic correlations. The results of this project will significantly improve our understanding of Svalbard’s Caledonides and the relationship of their structure to continental-scale tectonic processes which are the topics of ongoing international discussion.

2015-2019 National Science Centre, Poland, project Opus no 2015/17/B/ST10/03114 – PI J.Majka

Meso-neoproterozoic evolution of the Caledonian basement of SW Svalbard

The project focus on the medium- to high-grade rocks cropping out within the Southwestern Basement Province of Svalbard (SBP). The performed research delivered information on pressure-temperature (P-T) conditions under which the investigated rock units have been formed as well as about the timing of their formation. The main achievements of the project were: (1) recognition of low temperature-high pressure metamorphism within the Berzeliuseggene unit of Wedel Jarlsberg Land (WJL); (2) quantification of P-T conditions of metamorphism of the rock units metamorphosed during the Torellian Orogeny (Isbjørnhamna Group of WJL, unnamed unit on Sørkapp and Berzeliuseggene unit); (3) calculation of the geothermal gradient along which the subduction related Vestgötabreen Complex of Oscar II Land has been formed; (4) dating of the collision between southwestern Svalbard and an island arc during the Caledonian Orogeny to c. 485 Ma; (5) recognition and detailed characterization of the previously unknown Ellesmerian (c. 360 Ma) metamorphism within the basement mapped as Caledonian. All these quantitative pressure-temperature-time (P-T-t) data helped to broaden the understanding of the complicated geological evolution of the SBP and to realize that majority of those units have been metamorphosed during the Torellian Orogeny and then subsequently during the Caledonian Orogeny. The only exceptions are the high pressure rocks with clear oceanic affinity that underwent only Caledonian subduction-related metamorphism. Nevertheless based on the obtained P-T-t trajectories, it is proposed here that vast majority of the medium- to high-grade rocks of the SBP share similar metamorphic history. This allows to look at the scattered occurrences of these units as at the puzzle pieces that can be merged together to unravel the architecture of the pre-Caledonian southwestern Svalbard margin. Hence, it is now possible to compare the SBP to both paleocontinents Laurentia and Baltica and decide whether the SBP is a part of one or another. The latter has implications for paleogeographical reconstructions, thus also e.g. for distribution of mineral resources. A completely novel and surprising outcome of the project is the aforementioned discovery of the Ellesmerian metamorphic units on the island of Prins Karls Forland. A tentative tectonic model resulting from this project suggests the existence of the post-Caledonian suture between the SBP and the Franklinian Margin of Laurentia, a feature that provides the very first, strong line of evidence for connection between the SBP and the terranes on the NW Passage including the Pearya Terrane of northern Ellesmere Island.  

2014-2017 National Science Centre, Poland, project Preludium no 2013/11/N/ST10/00357 – PI K.Kośmińska