Castelo de Sonhos Gold Project
Project Location and Infrastructure
The Castelo de Sonhos project is situated in the southwestern Pará state. The property has easy road access all year round. The Cuiabá-Santarém road is a paved highway through the village of Castelo de Sonhos that goes south to Mato Grosso and north to Santarém. The Castelo de Sonhos property encompasses a 15km by 12km plateau with an average elevation of 650 meters (a.s.l.) and around 300-350 meters above the surrounding plains.
Details are reported in press release dated December 4, 2017 titled ‘TRISTAR GOLD CONTINUES TO EXPAND RESOURCES AT CASTELO DE SONHOS’
Castelo de Sonhos was one of the most famous and gold rich alluvial garimpos in all the Tapajós. The main gold rush took place there between 1985 and 1990 and it is estimated that 300,000 ounces of gold has been produced. By early 1995, Barrick Gold began to pay attention and soon recognised that the source of the alluvial gold was the Castelo de Sonhos plateau. So, in June 1995, after optioning the property, Barrick started an aggressive exploration program and discovered the conglomerate hosted gold mineralization.
Geology and Mineralization
The Castelo de Sonhos Formation is an isolated package of sandstones and conglomerates which form a roughly circular plateau rising 300 m above the surrounding plains. The plateau lies within the Amazon Craton, bounded on the east by volcanic, plutonic and sedimentary rocks of the Iriri-Xingu domain of the Central Amazon Province with ages dating back to ~3Ga (Santos et al., 2001; Bizzi et al., 2003), and on the west by the 2,030 – 1,860 Ma Tapajós-Parima Province, consisting of granodiorites, monzogranites and syenogranites that belong to the Creporizao and Parauari Suites. Both are intruded by the slightly younger monzo- and syeno-granite stocks of the Maloquinha Suite. The predominantly granitic Tapajós-Parima Province borders the Castelo de Sonhos Formation on the north and west.
The gold mineralization is intimately associated with the conglomerates. Strong gold mineralization is often seen with hematite alteration, and sometimes with silicification as well. But not all hematite-rich layers are gold-bearing. Although gold is predominantly found in conglomerate, it also occurs within an iron-rich hangingwall quartzite at Esperança South. Furthermore, gold is sometimes also found in iron-poor sediments of all types. In both conglomerates and quartzites, gold occurs as sub-millimeter grains within the matrix.