Le Crétacé inférieur de LEstramadura, au Portugal, m'apparaissait, lors-que j'en entrepris Vêtude, comme un thème de recherches à la fois séduisant et redoutable. Séduisant, car tout examen systématique avait été abandonné depuis plus de soixante ans, en dépit de la présence de classiques ensembles stratigraphiques, de la richesse des faunes et de la variété des fácies. Redoutable, car il m'amenait à suivre les traces de cet illustre géologue que fut Choffat. II était bien évident que je ne pouvais mener cette tache à son terme que grâce à de nombreux et bienveillants appuis. I'en ai large-ment beneficie, sinon même abuse. II m'est donc particulièrement agréable de remercier aujourd'hui tous ceux qui, durant les longues années de travail, m'ont aidé, conseillé et encouragé

In the 1970s, members of the U.S. National Committee on Tunneling Technology (USNCTT) recognized a need to review and improve contracting practices for underground construction. The committee conducted an intensive study and several workshop reviews, ultimately publishing a set of recommended practices in 1974.

Mining reconciliation is the comparison of estimated tonnage, grade and metal with actual measurements. The aims are to measure the performance of the operation, support the calculation of the mineral asset, validate the Mineral Resource and Ore Reserve estimates, and provide key performance indicators for short and long-term control (Morley, 2003). Ongoing, regular and efficient reconciliation should also highlight improvement opportunities and allow for proactive short-term forecasting by providing reliable calibrations to critical estimates. The concept is that of “measure, control and improve”.  <...>

Epithermal gold deposits in Chile are Cretaceous to Cenozoic in age. The ores and the volcanic rocks with which they are associated were generated at a noncollisional, ocean-continent convergent plate margin. They are related to long, slightly sinuous north-northeasttrending magmatic belts roughly parallel to the Pacific coast. Most of the deposits are associated with eroded volcanic centers and subvolcanic porphyries. North-south variations in the nature, extent, and timing of magmatism control the succession of mineralization events. In the Late Cretaceous, vein districts (e.g., E1 Bronce) and hydrothermal alteration zones were formed in central Chile.