Oribella represents a replacement or fracture controlled epithermal gold system superposed on a basalt "walk rock" Cu-Au porphyry and intrusive related breccia. It is within a metal rich part of the Middle Cauca Belt metallogenic province that extends for 120km. Oribella is centered between Continental Gold's Buritica Project and Anglo Ashanti Nuevo Chaquiro (Quebradona) Project and directly adjoins Orosur Mining's Anza Project.
Miranda exploration includes mapping, channel sampling, hand trenching, and soil sampling. Miranda soil sampling shows robust gold and copper anomalies that are spatially offset to each other and also an inferred epithermal zonation pattern in trace elements in relation to gold. The gold anomaly is approximately 500m by 250m and open in two directions. Limited hand trenching within the soil anomaly shows 11m @ 1.1 g Au/t in the subsurface. This mineralization extends to the limit of the trench. Combined Cu and Au values define an anomaly 600meters wide, centered on andesite porphyry stock and related breccia bodies.
Miranda recently expanded the Oribella Project with new applications, and is currently seeking a joint venture partner.
Location and means of access to the property
The Oribella Project comprises 20,000 hectares, located in the southwest Antioquia Department between the Betulia and Concordia municipalities.
The area is accessible from Medellín by paved roads to Concordia (National Route 60 and Secondary Departmental Bolombolo-Concordia Route). Time between Medellin and the Oribella Project is 3.5 hours.
Initial Exploration work and Model:
Miranda was attracted to the area by reports provided by Antioquia Gold and Soratama (Barrick Gold) indicating possible high sulfidation mineralization. Although alunite is found on the project, Miranda sees probably low sulfidation epithermal replacements in sandstones or tuffs that overprints copper mineralization in basalts, andesite porphyry and breccia. The mineralization, intrusives and breccia are centered on an inflection of a strand of the Romeral Fault Zone, which is an important fault control through the Middle Cauca Belt.
Reconnaissance prospecting away from epithermal mineralization shows generally fracture-controlled occurrences of to 5% copper. Generally copper highs do not correlate with gold highs suggesting a distinct gold overprint. There are large areas of distressed or single species dominant vegetation that is inferred to indicate high levels of trace elements. Some of these vegetation anomalies correlate with intense hematite alteration in road cuts. The vegetation anomalies may reflect extension of the gold-copper system on Oribella.
Oribella is located within the Middle Cauca Belt, which has a remarkably high distribution of large Au-Cu Porphyries, commonly showing related epithermal elements, and also epithermal replacement and vein systems without direct relationship to intrusives.
The Titiribi (8M ounces gold equivalent), La Mina (1.6M ounces gold equivalent), and Quebradona Districts (plus10M (?) ounces gold equivalent) are large porphyry deposits from 10 to 50km from Oribella. Buritica (3.8M ounces gold), Anza (plus 0.5M ounces gold) and Nuevo Guintar are epithermal discoveries 2 to 50km from Oribella.
Geology and mineralization:
The Oribella Project is lithology and includes oceanic domains of deep-water pelagic and turbidite- laminated sediments, and submarine tuffs tectonically juxtaposed against basaltic volcanic rocks. Both rock domains are localized along the western flank of Cauca-Patía physiographic depression.
At Oribella, the pelagic sediments occur to the west, transition rocks center, and volcanic domains to east. The lithilogic domains are opposed across the Mulatos and Tonusco faults. Locally folds associated with tectonic stacking and reverse faulting are observed.
Intrusive rocks including dacite and andesite hypabyssal intrusive rocks, and sedimentary-tuff sequences are cut by hydrothermally altered fault zones and tabular magnetic breccias. The breccias contain country rock and intrusive porphyritic rock fragments that show sodic-calcic actinolite and albite alteration, potassic alteration, and chlorite-epidote alteration. Disseminated sulfides and magnetite occur in the breccias. Closed spaced dikes are common on the project.
The Vereda La Sucre area on Oribella to date shows the most alteration, and a gold in soils anomaly in the range of 228 to 594 ppb and copper in soils anomaly in the range of 201 to 512 ppm, related to dacitic intrusions and locally carbonate rich, magnetic, hydrothermal and intrusion breccias.
Mineralization shows both structural and lithilogic controls, including local, fracture-controlled and pervasive silica replacement Alteration and mineral assemblages include moderate to high intensity sericite + chlorite + clays + pyrite ± quartz ± base metal (sphalerite > chalcopyrite > galena) ± carbonates. Alteration is zoned from silica poor at high elevations to silica rich at depth, and antimony + mercury is zoned with respect to gold. Gold locally is associated with selenium.
Regional Geological Assemblage, Oribella Project. Source: Lithology modified of Cediel et al., 2003; Caval Asesores S.A.S.
Inferred structural controls to mineralization; mineralization is also lithologically controlled with intense fracturing and replacement.
Mapping outcropping near surface gold mineralization, and tabular dikes and breccias suggest generally blind Cu-Au porphyry mineralization. Additional stream sediment sampling and prospecting is required to determine the extent of the gold-copper system at Oribella. The current target as defined by rocks, limited trenching and especially soils is of significant size (500m) and open to the north and south.
Copper Oxide Mineralization in Volcanic Rocks
Nature of interest and terms of acquisition:
Miranda acquired one exploration license and one application, totaling 10,700 hectares, on May 13, 2014 through an agreement with Antioquia Gold subject to a 0.5% NSR that can be purchased for US$1,500,000 and a 2% royalty to Soratama Gold (a wholly owned subsidiary of Barrick Gold Corporation).
Miranda owns 100% the property, subject to the royalties, by paying the license canon of US$62,715, that was due on May 14, 2014 and by reimbursing Antioquia Gold for the application payment of approximately US$40,000 when it is registered with the Agencia National de Mineria ("ANM") as a contract. No other obligations are required to keep the project in good standing and Miranda may drop or reduce the lands at any time.
Additional work in 2017, resulted in an expanded area potential, resulting in new applications to comprise a total area 20,000 contiguous hectares in the project.
Miranda will perform additional reconnaissance prospecting and conduct rock, soil and stream sediment sampling in to define areas of potential within the increased application area. Alteration mapping and a reinterpretation of geochemical and geophysical data will be completed.
Miranda is seeking a funding exploration partner. The strong soil anomaly will be delineated at Vereda La Sucre. This anomaly is ready for initial drill testing.