Contrasted granite emplacement modes within an oblique crustal section: The closepet granite, South India

TThe Closepet Granite, in South India, is a large, syntectonic Archaean granitic complex. Differential erosion has exposed it from the lower (25 km) to upper crust (5 km). Four main parts are recognized from bottom to top: (i) A root zone, where magmas formed, collected and rose within active shear zones, leaving schlieren behind. The surrounding crust was highly ductile, leading to diffuse deformation. (ii) A transfer zone, where the magma was progressively enriched in K-feldspar phenocrysts during its ascent. In this part, the granite rose as a mush moving as a whole within a less ductile crust. Slow cooling was responsible for a long magma residence time under conditions favoring to fabric enhancement and strain partitioning, leading to horizontal and vertical melt migration. (iii) A gap(dyke complex that acted as a filter zone), were the ascent of the mush was stopped. Probably due to high phenocryst load and high viscosity contrast with the wall rocks. Only crystal-poor melts could continue their ascent through the dykes. (iv) A zone of shallow intrusions, where the liquids extracted from the mush filled small, elliptical plutons, cooling quickly and developing only very weak fabrics. © 2001 Elsevier Science Ltd. All rights reserved

Aequorin-based measurements of intracellular Ca(2+)-signatures in plant cells

Due to the involvement of calcium as a main second messenger in the plant signaling pathway, increasing interest has been focused on the calcium signatures supposed to be involved in the patterning of the specific response associated to a given stimulus. In order to follow these signatures we described here the practical approach to use the non-invasive method based on the aequorin technology. Besides reviewing the advantages and disadvantages of this method we report on results showing the usefulness of aequorin to study the calcium response to biotic (elicitors) and abiotic stimuli (osmotic shocks) in various compartments of plant cells such as cytosol and nucleus