In 2004, Colibri acquired the 3400 hectare Leon Property in north-central Sonora, Mexico. The Company was able to consolidate 10 old claims into this claim block. Several extensive underground mines exist in the immediate area. These have produced significant gold-silver, lead-zinc, or copper-molybdenum. Like the Colibri Property, the Leon Project occurs within a region of known, large tonnage polymetallic deposits. Most notable of these is the El Creston molybdenum deposit, located directly east of the Leon Property. El Creston was recently acquired by Georgia Ventures, Inc., with an extensive drill program planned for the near future (see postings on www.sedar.com). Based on recent mapping and sampling (see illustrations below), Colibri geologists believe that the El Creston deposit has been detached and displaced northeastward from a fertile belt of molybdenum-copper bearing quartz veins and porphyries that outcrop in the eastern Leon Property.
Initial exploration on the Leon Project during 2006 focused on silver-gold mineralization spatially associated with the Las Amarillas and El Tramado mines in the western part of the property. Geologic mapping and rock-chip sampling revealed a network of mineralized quartz veins within an altered Cretaceous granodiorite host. Assays yielded elevated values of silver with local gold anomalies, but relatively minor abundance of base metals. Additional exploration during 2007 extended mapping and chip sampling to the east edge of the Leon Property. This endeavor identified a broad belt of molybdenum-copper mineralization associated with emplacement of quartz veins, Tertiary rhyolite porphyry dikes, and Tertiary granite into Cretaceous granodiorite and Precambrian gneiss host rocks. Also recognized and mapped was a zone of low angle normal faults (detachment faults) which truncate the east edge of this mineralized belt. As depicted in cross section below, Colibri geologists believe that the Leon molybdenum-copper belt may represent the decapitated roots or feeder system of the El Creston molybdenum deposit.
Recent exploration work during summer of 2007 has delineated several pronounced soil anomalies in the eastern part of the Leon Project area. Molybdenum, copper, and zinc assays are significantly elevated in soils derived from host rocks of certain veins and dike networks sampled earlier. Soils developed along parts of the detachment fault system are also mineralized, suggesting that metals have been remobilized and concentrated along this well-exposed low-angle breccia zone.
Based on recent exploration, Colibri geologists believe that the Leon Property has the potential to host separate bulk-tonnage open-pit mines, with an emphasis on silver-gold in the west, and copper-molybdenum and other base metals in the east. Geologic mapping, rock chip sampling, and soil sampling have provided important clues about which exploration targets to prioritize on the property. Drill targets are now delineated, and Colibri plans to initiate an extensive drill program during 2007-08 season. Illustrations showing pertinent results of exploration on the Leon Project are posted below. Additional maps and photographs may be accessed in the slide show linked to Colibri’s June 30, 2007 News Release.
(Click to enlarge)
Magnetic intensity map and molybdenum soil anomalies superimposed on Leon geologic map. White lines display ppm Mo in soils
Magnetic intensity map and copper soil anomalies superimposed on Leon geologic map. White lines display ppm Cu in soils
Geologic base layer for magnetic anomaly maps
Magnetic intensity map of Leon Project, showing location of survey lines
Drill Hole Locations, 2008
Geologic map of the Leon Project, updated June, 2010
Satellite image of the Leon Property and vicinity, showing results of recent Molybdenum assays and geological mapping
Leon Cross Section
Updated geologic map of the Leon property, showing Molybdenum and gold assays of rock chip samples collected through January, 2008.
Contour map showing Molybdenum assays of rock chip samples (green circles). Base layer is same as geologic map at left.
Aeromagnetic anomaly map superimposed on the Leon Property. Red and orange colors represent high values; blue and white colors represent low values. Colored dots represent copper assays in soils.
Rock Chip Assays from NW quarter of Leon Project
Rock Chip Assays from SW quarter of Leon Project
Satellite image showing location of samples and major low angle structures within the Leon Project
Leon Claim Map
Cu-Mo Geochem Map
Updated Leon claim map, showing location of the Leoncito claim, acquired in summer of 2007