FÉRAUD , Gilbert

International audience

The Taoudenni basin dike swarm (northern Mali) is one of the densest dike complexes of the previous termCentral Atlantic Magmatic Provincenext term (CAMP). A combined geometrical (dike directions), geochemical (major and trace elements, Sr and Nd isotopes), and geochronological (40Ar/39Ar dating) study is presented for the first time on the...

The combined use of the Rb-Sr and 40Ar-39Ar laser probe methods allows confirmation of the existence of excess argon in phengites from eclogites from the Sesia zone (Western Alps) despite systematic 40Ar-39Ar plateau ages. 40Ar-39Ar phengite ages from two different areas show integrated age spreads between 65.4 ± 0.3 Ma and 109.5 ± 0.4 Ma. The...

International audience

Rb­Sr and 40Ar/39Ar data mainly ranging from 345 5 to 361 5 Ma and from 348.4 1.4 to 364.6 1.4 Ma, respectively, have been obtained on phengite from the HP/LT rocks from the Ile de Groix (Armorican Massif, France), which represents one of the few occurrences of Variscan blueschists. Petrological data show two blueschist-facies units,...

Drilling at Soultz-sous-Forêts, France, conducted as part of the European Hot Dry Rock (HDR) Project, penetrated granitic basement down to 5,080 m and revealed a porphyritic monzogranite that has no equivalent in the granitic outcrops of adjacent basement aeras. The EPS-1 borehole core (from 980 to 2,230 m) shows a monzogranite that has a...

The Tamlalt–Menhouhou gold deposit belongs to the Neoproterozoic–Palaeozoic Tamlalt inlier located in the Eastern High-Atlas (Morocco). It occurs in altered Upper Neoproterozoic bimodal volcanic and volcano-sedimentary units outcropping in the Tamlalt–Menhouhou area. Gold mineralization has been identified in quartz veins related to shear-zones...

• Variations of dissolved arsenic concentration according to water/rock interactions • As in river water originates from Perm-ian and Hercynian metamorphic rocks • 4.2 tons⋅year − 1 of dissolved As is transferred to the Mediterranean Sea. • The use of a mixing model supports the non-conservative nature of arsenic. A detailed study on arsenic...

International audience

The peak activities of continental flood basalts are currently considered as huge and brief (1 m.y.) magmatic events, with strong implications for geodynamics and biotic turnover. New 40Ar/39Ar dates on the Karoo flood basalts (southern Africa) show a longer duration of magmatism (8 m.y., with 6 m.y. for the main volume) with an apparent...

Zircons from the polyphase Tamlalt-Menhouhou gold deposit were examined in order to define the age of the sodic metasomatism (albitization), which is assumed to be related to the primary gold mineralization. Magmatic and hydrothermal zircons were distinguished in albitized banded rhyolitic metatuffites (BRM) and in albitite on the basis of...

Raw data are collected in five measurement locations along the Var river. It is assumed that some locations interact with each other, whereas others do not. In such a context, we are interested in determining the contribution of each location and in better understanding the water exchanges that are involved. Organic components can also be...