Geosystems and Earth Evolution

Objective: different tectonic regimes/models have been proposed for the early- and mid- Earth life, some quite different from the modern regime, suggesting a secular evolution of plate tectonics. Members of this theme resource to macro- and micro-scale observations of tectonic structures, igneous, metamorphic and detrital sedimentary rocks and in-situ geochemical analyses of minerals to unravel geodynamic processes affecting their formation or sources. To tackle these objectives, a multidisciplinary approach is required, resourcing to classical petrographic and sedimentological studies, but also challenging in-situ geochemical analyses, petrological experiments, multivariate statistics, and crystallography. This theme is mainly supported by an ERC-StG (FINGER-PT, GAP-101117053).

Objective: to contribute to the knowledge of the palaeogeography and geodynamic evolution of the different palaeocontinents, creating new data and strength or correct the existing schemes, in order to improve the accuracy of paleogeographical maps and constrain the position and configuration of particular paleocontinents in different moments. This will be also addressed through stratigraphic correlation of contemporaneous succession in different regions and Paleozoic extreme climatic events, namely the BODA global warming event (Ordovician), the great Hirnantian glaciation (Ordovician) and the adaptations and modifications of floras in the Carboniferous-Permian transition, due to hot, dry conditions and rising oxygen levels. This theme makes a decisive contribution to understanding the biotic consequences of climate change in the Earth's past, particularly in the Palaeozoic. The palaeogeographical distribution of marine invertebrates and plants is strongly controlled by the temperature, latitude, geography and, in the specific case of the end of the Palaeozoic, the concentration of oxygen. The Late Ordovician represents a critical moment on Earth history, preceding the 2nd biggest extinction known in the Phanerozoic. Thus, the study of the Late Ordovician is paramount to better understand how critical events such as the BODA Event and the end-Ordovician glaciation, which preceded the second biggest extinction known in the Earth’s history, affected the biotas and how they reacted. Pollen analysis enables regional observation of vegetation evolution. The analysis of Non-Pollen-Palynomorphs contributes to a local characterization of environmental conditions, and still allowing a relationship with anthropic behaviours (pastoral or agricultural). These kind proxies allow the understanding the impact of Quaternary climate events, the human behaviour and the increasing anthropic impact on the landscape and the quaternary faunal behaviour too.

Objective: to contribute to establish the phenomena and orogenic events that have shaped the continental crust through time using a multidisciplinary approach at multiple scales. It also includes petrogenetic processes that have led to ore formation events, commonly linked to orogenic or tectonic processes. Members contributing to this theme resource to a wide range of techniques and methods, including geological and structural mapping, petrology, geochemistry and geochronology. One theme is related to using radiogenic isotopic systems (Sm-Nd, Rb-Sr, Lu-Hf) to investigate the evolution of magmatic sources in different terranes. This contributes to constrain the geodynamic evolution of different terranes. Other members apply different petrochonometers that record different P-T-t conditions in the evolution of mountain belts to constrain timings of metamorphic, hydrothermal, or magmatic events and processes. These include the genesis of ore deposits. The main targets of current projects are the Pan-African/Cadomian, the Variscan and the Alpine orogenies.

Objective: the characterisation of palaeoenvironments and palaeoclimates in order to constrain the changes and determine their effects on the biotas and the adaptations of particular groups to the new conditions. These objectives will be achieved through the study of new fossil assemblages and taxonomic revision of others, integrated with the sedimentological and geochemical analysis. The main focus of the team are the changes in biotic communities typically associated with Paleozoic extreme climatic events, namely the BODA global warming event (Ordovician), the great Hirnantian glaciation (Ordovician) and the adaptations and modifications of floras in the Carboniferous-Permian transition, due to hot, dry conditions and rising oxygen levels.This theme makes a decisive contribution to understanding the biotic consequences of climate change in the Earth's past, particularly in the Palaeozoic. The palaeogeographical distribution of marine invertebrates and plants is strongly controlled by the temperature, latitude, geography and, in the specific case of the end of the Palaeozoic, the concentration of oxygen. The Late Ordovician represents a critical moment on Earth history, preceding the 2nd biggest extinction known in the Phanerozoic. Thus, the study of the Late Ordovician is paramount to better understand how critical events such as the BODA Event and the end-Ordovician glaciation, which preceded the second biggest extinction known in the Earth’s history, affected the biotas and how they reacted. Pollen analysis enables regional observation of vegetation evolution. The analysis of Non-Pollen-Palynomorphs contributes to a local characterization of environmental conditions, and still allowing a relationship with anthropic behaviours (pastoral or agricultural). These kind proxies allow the understanding the impact of Quaternary climate events, the human behaviour and the increasing anthropic impact on the landscape and the quaternary faunal behaviour too.

Objective: to contribute to the characterisation of sedimentary basins, either in terms of provenance analysis, depositional tectonic settings or changing depositional environments. This will be addressed through fieldwork observation and measurements, geological mapping, sampling, sedimentological analyses, geochemical characterisation of heavy minerals and paleontological studies. Additionally, some members apply multiscale characterization of geological heterogeneities in sedimentary basins, from pore to seismic scale, resourcing to geological models’ designing (ex., conceptual, 3D, geocellular, etc). One of the research themes is the study of the late Neoproterozoic-Palaeozoic of the Central Iberian Zone. Through geological mapping, lithostratigraphy and biostratigraphy, the team contributes to a deeper insight onto the geodynamics of the Iberian massif and particularly the evolution of peri-Gondwanan terranes during the Ordovician, and the great Cadomian and Variscan cycles. Another theme is the development of petrogeochemical tools applied to heavy minerals that can be used to improve provenance analyses. This allows a better characterisation of source rocks and a better understanding of source-to-sink dynamics. Other relevant contributions include rock classification systems, based on syn- and post-depositional, biostratinomic and fossil-diagenetic processes.

Objective: to improve the current understanding about the biodiversity and the ecosystems of the Earth's past, and of the processes of integrating biological information into the geological record, to reveal new phylogenetic, evolutionary, ichnological and ecological information on past organisms and the relationship of their fossils with the underlying sedimentary rocks. This will be addressed through classical palaeontology studies of fossil assemblages, from low taxonomy (description of new species) to high taxonomy (systematics and phylogenetic analysis), and through the analysis of exceptional fossils, especially ichnofossils, that reveal new behaviours for particular groups. The team's main focuses are the systematics and palaeoecology of trilobites, ammonites, dinosaurs and other vertebrates and plants. In what concerns the trilobite line of research, the update of the systematic knowledge of the group is crucial for the revised Trilobite Treatise. The team is now covering the Iberian occurrences from Cambrian to Devonian assemblages. On the other hand, the evolutionary success of the group throughout the Palaeozoic justifies the interest in the defence strategies adopted by trilobites, behaviours common in today's marine arthropods such as gregariousness, synchronised reproduction and sheltered ecdysis, or migrations in a conga line, originated in the Palaeozoic, more than 400 Ma ago, in this group. About dinosaurs, the abundant Portuguese fossil record, makes the study of this group important to understand the faunas of the Mesozoic, especially the numerous sites with paleoichnological record, which allows us to have new and important data on the social behaviour of these animals, as well as to better understand the sedimentary contexts where their footprints are preserved.

Objective: to studie the changes in biotic communities during extinction events, in particular variations in diversity and patterns of effects on different groups, as well as surviving communities, as a way of obtaining information on their causes. For instance, extreme climate events involve huge loss of species of organisms in a short period of time, which then leads to the development and adaptation of new life forms and biological groups. During the Phanerozoic there were five of these major extinction events, and one of the aims of this theme is to attend those climatic crises. This is addressed through the study of new fossiliferous assemblages and taxonomic revision of others, coming from strategic regions, and focusing on ecologically more informative groups. One relevant theme is the study the Late Ordovician Mass Extinction, the 2nd biggest extinction. The peri-Gondwanan marine invertebrates fossil assemblages are paramount due to their strategical position, close to the maximum development of the Hirnantian glaciation, which has been largely related to the extinction. Further work is required to understand the extent of this glaciation and its impacts on the different biological groups. Another big focus is the Carboniferous rainforest collapse, the minor marine and terrestrial extinction event, that occurred at the end of the period, caused by climate change. Finally, the group is also focused on severe climatic events during the Quaternary. Although driven by natural factors, these events had profound impact in landscape and vegetation dynamics, demanding the development of adaptive behaviours by human communities. One research topic is to understand how Pleistocene glaciations conditioned the evolution of humans and fauna during this period, in particular that of the Neanderthals. Furthermore, since the Middle and Late Holocene, mostly from the Bronze Age onwards, human activities became a major driver of landscape change, in the long-term also creating important challenges as soil degradation. Available information highlights that current environmental changes are the consequence of long-term evolution of human-nature relations that can only be understood through a deep-historical approach, using technical tools and theoretical approaches of paleoenvironmental sciences such as Palynology.