ALBERT

Description: Gypsum crystals are found at the well perforation of observation well Ktzi 202 of the test site for CO2 storage at Ketzin, Germany. XRD analysis confirms pure gypsum. Fluid samples before and after CO2 injection are analyzed. Geochemical modeling is conducted to identify the mechanisms that lead to gypsum formation. The modeling is carried out with PHREEQC and Pitzer database due to the high salinity of up to 5 mol per kg water. Due to their significantly higher reactivity compared to other minerals like silicates, calcite, dolomite, magnesite, gypsum, anhydrite, and halite are considered as primary mineral phases for matching the observed brine compositions in our simulations. Calcite, dolomite, and gypsum are close to saturation before and after CO2 injection. Dolomite shows the highest reactivity and mainly contributes to buffering the brine pH that initially decreased due to CO2 injection. The contribution of calcite to the pH-buffering is only minor. Gypsum and anhydrite are no geochemically active minerals before injection. After CO2 injection, gypsum precipitation may occur by two mechanisms: (i) dissociation of CO2 decreases activity of water and, therefore, increases the saturation of all minerals and (ii) dolomite dissolution due to pH-buffering releases Ca2+ ions into solution and shifts the mass action to gypsum. Gypsum precipitation decreases with increasing temperature but increases with increasing partial CO2 pressure. Our calculations show that calcium sulfate precipitation increases by a factor of 5 to a depth of 2000 m when Ketzin pressure and temperature are extrapolated. In general, gypsum precipitation constitutes a potential clogging hazard during CO2 storage and could negatively impact safe site operation. In the presented Ketzin example, this threat is only minor since the total amount of gypsum precipitation is relatively small.

Description: The scope of the Science Plan is to describe the scientific background, applications, and activities of the Environmental Mapping and Analysis Program (EnMAP) imaging spectroscopy mission. Primarily, this document addresses scientists and funding institutions, but it may also be of interest to environmental stakeholders and governmental agencies. It is designed to be a living document that will be updated throughout the entire mission lifetime. Chapter 1 provides a brief overview of the principles and current state of imaging spectroscopy. This is followed by an introduction to the EnMAP mission, including its objectives and impact on international programs as well as major environmental and societal challenges. Chapter 2 describes the EnMAP system together with data products and access, calibration/validation, and synergies with other missions. Chapter 3 gives an overview of the major fields of application such as vegetation and forests, geology and soils, coastal and inland waters, cryosphere, urban areas, atmosphere and hazards. Finally, Chapter 4 outlines the scientific exploitation strategy, which includes the strategy for community building and training, preparatory flight campaigns and software developments. A list of abbreviations is provided in the annex to this document and an extended glossary of terms and abbreviations is available on the EnMAP website.

Description: The Menderes Massif in Turkey represents one of the largest metamorphic core complexes in the world. It is regarded as a section of lower continental crust exhumed along low-angle detachment faults in the Late Miocene during a period of extension that affected the entire Aegean province. Syn-extensional magmatic activity within the Menderes metamorphic core complex is predominantly felsic forming several plutons, whereas mantle-derived magmatism has not been known so far. Here, we present a detailed study of the petrology and geochemistry of previously unreported mafic to intermediate lamprophyres within the Menderes Massif and assess their role in the geodynamic evolution of the core complex. The Menderes lamprophyres are mostly kersantites, with 49–60 wt % SiO2, 3.2–8.4 wt % MgO, 100–360 ppm Cr, 32–132 ppm Ni and Mg# of 37–50. Positive Pb and negative Ti–Nb–Ta anomalies suggest a clear orogenic affinity. Isotopes of Sr and Pb are relatively radiogenic (87Sr/86Sr = 0.70609–0.71076; 206Pb/204Pb = 18.88–19.03, 207Pb/204Pb 〉 15.71), while Nd is unradiogenic (εNd =  −1.4 to −3.2). Most phenocrysts are sharply zoned with a primitive core (Mg# 77–85, up to 0.95 wt % Cr2O3 in clinopyroxene; Mg# 72–76 in amphibole) and a more evolved rim (Mg# 68–74, 〈0.25 wt % Cr2O3 in clinopyroxene; Mg# 69–71 in amphibole). Trace element ratios between different cores may vary significantly (e.g. Dy/Yb 2–5 in amphiboles), whereas rims show less variation but are more enriched than the cores. U–Pb dating of zircons provides an age of 15 Ma for the lamprophyres, coeval with the syn-extensional granite magmatism. The Hf isotopic composition of magmatic zircons is variably unradiogenic (176Hf/177Hf15Ma = 0.28248–0.28253, εHf15Ma = −8.6 to −10.5), while zircon xenocrysts with dominantly Cadomian and older ages show highly variable Hf isotopic signatures at the time of lamprophyre emplacement (εHf15Ma = −7.6 to −46.7). The orogenic geochemical signature of the lamprophyres’ parental melts is similar to nearby orogenic lavas from the West Anatolian Volcanic Province. Variation in bulk-rock εNd and in Dy/Yb ratios of phenocryst cores reflect moderate mantle heterogeneity. The chemical heterogeneity of phenocrysts and zircon εHf values implies intense hybridisation of proto-lamprophyre melts with felsic crustal melts, most probably derived from the melting of augen gneisses of the Menderes basement. We propose that fluid released from the lamprophyre primary melt had a decisive impact on crustal melting and the formation of granitic plutons within the Menderes core complex.