Projecten per jaar
Samenvatting
The geochemical signatures of sparry calcite-sealing expansion breccias, calcite veins, and host clasts were analyzed for their strontium (87Sr/86Sr) and oxygen and carbon (δ18O, δ13C) stable isotopic signatures. The breccias occur within
the Lower Cretaceous Maiolica Formation. Related but different breccias are found in a few places in the Upper Cretaceous to Eocene Scaglia Rossa Formation of the Umbria-Marche Apennines fold-and-thrust belt (Italy). We propose hydraulic fracturing by fluid overpressure as a possible mechanism for generation of the breccias in these formations. Our data are compatible with the hypothesis of a hydraulically fractured breccia formed by cyclic buildup and rapid decompression of CO2-rich fluids, with overpressures generated by entrapment of CO2 by structural and stratigraphic seals. Strontium and oxygen isotope ratio data suggest that the CO2-rich fluids may have originated from carbonate metasomatism of the mantle, resulting from subduction of carbonate-rich lithologies constituting the downgoing slab. This is consistent with previous conceptual models inferring that in the central part of the Northern Apennines, which is characterized by thick continental crust, CO2-rich fluids derived from mantle metasomatism would become trapped in structural seals, creating high
fluid overpressures.
the Lower Cretaceous Maiolica Formation. Related but different breccias are found in a few places in the Upper Cretaceous to Eocene Scaglia Rossa Formation of the Umbria-Marche Apennines fold-and-thrust belt (Italy). We propose hydraulic fracturing by fluid overpressure as a possible mechanism for generation of the breccias in these formations. Our data are compatible with the hypothesis of a hydraulically fractured breccia formed by cyclic buildup and rapid decompression of CO2-rich fluids, with overpressures generated by entrapment of CO2 by structural and stratigraphic seals. Strontium and oxygen isotope ratio data suggest that the CO2-rich fluids may have originated from carbonate metasomatism of the mantle, resulting from subduction of carbonate-rich lithologies constituting the downgoing slab. This is consistent with previous conceptual models inferring that in the central part of the Northern Apennines, which is characterized by thick continental crust, CO2-rich fluids derived from mantle metasomatism would become trapped in structural seals, creating high
fluid overpressures.
Originele taal-2 | English |
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Titel | 250 Million Years of Earth History in Central Italy: Celebrating 25 Years of the Geological Observatory of Coldigioco |
Redacteuren | Christian Koeberl, David Bice |
Plaats van productie | Denver |
Uitgeverij | Geological Society of America, Boulder Co. USA |
Hoofdstuk | 13 |
Pagina's | 251-269 |
Aantal pagina's | 19 |
Volume | 542 |
DOI's | |
Status | Published - 11 sep 2019 |
Publicatie series
Naam | Special Paper of the Geological Society of America |
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ISSN van geprinte versie | 0072-1077 |
Vingerafdruk
Duik in de onderzoeksthema's van 'Expansion breccias in Lower Cretaceous Apennine pelagic limestones: II. Geochemical constraints on their origin'. Samen vormen ze een unieke vingerafdruk.Projecten
- 4 Afgelopen
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HERC46: FWO Hercules MZW: Een sprong in het ongewisse met stabiele isotopen biogeochemie
Claeys, P., Elskens, M., Olde Venterink, H., Nys, K., Tys, D., Kervyn De Meerendre, M., Huybrechts, P., Van Griensven, A., Huysmans, M., Thiery, W. & Snoeck, C.
1/05/18 → 30/04/22
Project: Fundamenteel
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SRP2: Tracers van verleden en heden global changes
Claeys, P., Elskens, M., Huybrechts, P., Gao, Y., Kervyn De Meerendre, M., Claeys, P., Baeyens, W. & Dehairs, F.
1/11/12 → 31/10/24
Project: Fundamenteel
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FWOTM591: Petrografie en geochemie van impact materiaal en proximale ejecta in het zuiden van Mexico in het kader van de 2012-2013 IODP/ICDP boringen van de Chicxulub krater
Claeys, P. & Belza, J.
1/10/11 → 30/09/15
Project: Fundamenteel
Uitrusting
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Nu-Carb sample preparation unit
Philippe Claeys (Manager)
Archeologie, Milieuveranderingen, en Geo-ChemieUitrusting/faciliteit: no e-resource/single sited
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Nu-Instruments IS-Perspective Isotope Ratio Mass Spectrometer
Philippe Claeys (Manager)
Archeologie, Milieuveranderingen, en Geo-ChemieUitrusting/faciliteit: no e-resource/single sited
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Nu Perspective Automatic Dual Inlet Isotope Ratio Mass Spectrometer (IRMS)
ScheikundeUitrusting/faciliteit: no e-resource/single sited