France. Service de la carte geologique de France North Decimal Degree 45.1792 South Decimal Degree 44.8192 East Decimal Degree 1.9300 West Decimal Degree 1.1155 Relief shown by hachures. Principal meridian: Paris. Longitude is given in centesimal values (100 grades = 90 degrees) .The Service de la carte geologique de la France was integrated to the BRGM to become the only France Service geologique national. Based on "Carte topograqphique de l'etat major."