Person: Suárez González, Pablo
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First Name
Pablo
Last Name
Suárez González
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Geodinámica, Estratigrafía y Paleontología
Area
Estratigrafía
Identifiers
5 results
Search Results
Now showing 1 - 5 of 5
Item Do stromatolites Need Tides to trap Oodis? insights from the Coastal-Lake carbonates of the Leza FM (Early Cretaceous, N Spain)(Abstract book / Tidalites 2012: 8th International Conference on tidal environments, Caen, France, july 31- august 2, 2012) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José RamónItem Sedimentology of ancient coastal wetlands: insights from a cretaceous multifaceted depositional system(Journal of sedimentary research, 2015) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José RamónCoastal wetlands are prominent modern environments widely studied in geomorphology and ecology, but the term ‘‘coastal wetland’’ is still barely used for the sedimentological classification of ancient deposits. The depositional system studied here (Leza Formation, Cameros Basin, Early Cretaceous, N Spain) includes diverse carbonate and clastic facies deposited at the sea–land transition, and is an illustrative example of the wide array of sedimentary environments that may occur in coastal wetlands systems. The studied system was composed mainly of carbonate water bodies whose salinity ranged from fresh to brackish and near-marine, and which had variable input of clastic material due to their lateral connection with alluvial fans. In addition, the system also included carbonate water bodies with stronger marine influence, tide-influenced oolitic areas, and relatively restricted evaporative settings. The deposits of all these environments occur alternating with each other throughout a unit 30–280 m thick, and they range from continental to marine conditions in a relatively small area (approximately 10 km 3 30 km). Thus, this sedimentological study of the Leza Fm provides an ideal opportunity to investigate challenging ancient deposits with both continental and marine features. Comparison with other modern and ancient coastal settings allows the conclusion that ‘‘coastal wetland’’ may be the most accurate sedimentological classification for the Leza Fm, since it was not part of a major coastal system (e.g., delta or estuary). A series of general sedimentological characteristics of coastal wetland deposits are gathered from the Cretaceous case study and from the modern and ancient examples examined. These characteristics include: predominance of shallow-water facies; common subaerial exposure and edaphic features; great variety of interrelated continental, transitional, and marine environments with contrasting hydrodynamic and hydrochemical conditions; and low-diversity biotic communities, including both continental and marine fossils, as well as fossils of ambiguous affinities.Item Origin and significance of lamination in Lower Cretaceous stromatolites and proposal for a quantitative approach(Sedimentary geology, 2014) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José RamónStromatolite lamination is typically defined as alternation of dark and light laminae. Study of Lower Cretaceous stromatolites fromthe Leza Fm(N Spain) supports this statement, but recognises additional complexities in lamination that have implications for interpreting accretion processes. These stromatolites are partial analogues of present-day coarse-grained carbonate stromatolites in the Bahamas and Shark Bay (Australia) that mainly form by trapping and binding carbonate sand. The Leza examples contain both grain-rich and micrite-rich laminae with scarce particles, suggesting that they accreted both by trapping and not trapping grains. Lamination in modern and ancient coarse-grained stromatolites is commonly defined by thinmicritic crusts that formed during interruptions in accretion and separate contiguous grainy laminae (repetitive lamination). Leza examples also contain these thin hiatal crusts and locally showrepetitive lamination, but their conspicuous macroscopic lamination is defined by thicker alternating grain-rich and micrite-rich laminae (alternating lamination). This indicates that, although hiatuses in accretion occurred, change in accretion process was the main cause of macroscopic lamination. These differences in accretion processes and lamination styles between Leza examples and modern coarse-grained stromatolites may reflect differences in their environmental settings. Modern examples occur in shallow marine tidal environments, whereas Leza Fm coarse-grained stromatolites developed in ideinfluencedwater-bodies in coastal-wetlands that experienced fluctuations inwater salinity and hydrochemistry. Analysis of lamina-thickness in these Cretaceous stromatolites and similar published examples provides a quantitative approach to the processes that underlie stromatolite lamination.Item A coastal paradise for Aptian microbialites (Early Cretaceous, N Spain(11th Workshop on Alpine Geological Studies & 7th IFAAn, September, 7-14, 2013) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José Ramón; Riding, R.Item Ooids forming in situ within microbial mats (Kiritimati atoll, central Pacific)(Paläontologische Zeitschrift, 2021) Suárez González, Pablo; Reitner, JoachimOoids (subspherical particles with a laminated cortex growing around a nucleus) are ubiquitous in the geological record since the Archean and have been widely studied for more than two centuries. However, various questions about them remain open, particularly about the role of microbial communities and organic matter in their formation and development. Although ooids typically occur rolling around in agitated waters, here, we describe for the first time aragonite ooids forming statically within microbial mats from hypersaline ponds of Kiritimati (Kiribati, central Pacific). Subspherical particles had been previously observed in these mats and classified as spherulites, but these particles grow around autochthonous micritic nuclei, and many of them have laminated cortices, with alternating radial fibrous laminae and micritic laminae. Thus, they are compatible with the definition of the term ‘ooid’ and are in fact very similar to many modern and fossil examples. Kiritimati ooids are more abundant and developed in some ponds and in some particular layers of the microbial mats, which leads to the discussion and interpretation of their formation processes as product of mat evolution, through a combination of organic and environmental factors. Radial fibrous laminae are formed during periods of increased supersaturation, either by metabolic or environmental processes. Micritic laminae are formed in closer association with the mat exopolymer (EPS) matrix, probably during periods of lower supersaturation and/or stronger EPS degradation. Therefore, this study represents a step forward in the understanding of ooid development as influenced by microbial communities, providing a useful analogue for explaining similar fossil ooids.