Regional Geology

Runruno project resides within the Caraballo district, whose geology largely consists of pre-Cretaceous to Early Cretaceous basement rocks consisting of ophiolite and schist underlying Late Cretaceous to mid-Miocene age volcanics, volcanoclastics and sedimentary rocks. The strata are intruded by the Upper Miocene Palali – Cordon Complex which is overlaid by Pleistocene lava flows, pyroclastics, marine sediment and Pliocene Matuno Formation.

Structurally speaking, the region is largely cut north south and moderate to shallowly dipping extensional structures. The area also has NW-trending, steep crosscutting arc-parallel faults which are interpreted as strike slip features. The area has undergone intrusion and uplift subsequent to and during the formation of the Palali-Cordon Alkali Intrusive Complex and is interpreted as an intra-arc basin.

Runruno Regional Geology
Runruno exploration model

Project Geology

Runruno sits at the intersection of the borders of two district-scale calderas, major NW and NE fault lines and a number of small volume, late composite volcanic centres. Mineralization at Runruno is hosted by a shallow-dipping fault zone of potassically-altered sericitized and brecciated tuffs and andesites which have been variably pyritized and silicified. Gold mineralization is preferentially hosted within fractures, faults, and breccias.

The style of gold mineralisation in Runruno is mostly as fine disseminations associated with pyrite and/or molybdenite. The origin of the mineralisation is believed to be fault controlled. Gold mineralisation is hosted by low angle structures enveloped by bluish to gray colour altered wall rock containing fine-grained sulphides, molybdenite and tennantite. Gold occurs both as megascopic native particles and as microscopic inclusions in pyrite. The small nature of these intrusions results in the gold mineralisation at Runruno being refractory.