43-101 2008 Technical Report On The La Fortuna Project, Durango ...
43-101 2008 Technical Report On The La Fortuna Project, Durango ...
43-101 2008 Technical Report On The La Fortuna Project, Durango ...
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6.0 MINERALIZATION<br />
Gold mineralization on the Property is hosted by thinly-bedded volcaniclastic rocks of the Lower Volcanic<br />
Series and adjacent dacitic sills or dikes. <strong>The</strong> mineralized zones have locally been oxidized to depths<br />
greater than 200 m below surface but an average depth is more in the order of 150 m.<br />
Mineralization occurs in a series of northwest-trending lenses up to 150 m in length and 40 m in width.<br />
This northwest trend probably reflects individual mineralized volcaniclastic units. While the trend of the<br />
individual mineralized bodies is to the northwest, the overall trend of ALL the mineralized bodies is to the<br />
northeast, suggesting a possible northeast-trending structural control such as a structure through which the<br />
mineralizing fluids gained access to the permissive host rocks.<br />
Mineralization in thinly-bedded volcaniclastic rocks is disseminated and occurs with earthy red hematite<br />
(Plate 2) or in narrow fractures with earthy red hematite (Plate 2). Quartz is rare although quartz veinlets<br />
are present locally.<br />
Plate 2. Mineralized thinly-bedded volcaniclastic rocks.<br />
Due to extensive oxidation, primary hydrothermal alteration is difficult to characterize. Silicification is<br />
rare, although some of the chalcedonic silica may have formed by replacement of volcaniclastic units.<br />
Argillic alteration is widespread but may be related to supergene processes. Strong potassic alteration in<br />
the form of biotite and potassium feldspar in fractures with some secondary copper minerals within<br />
intermediate intrusive rocks may suggest a porphyry copper environment at depth (Arturo Guerrerro,<br />
personal communication).<br />
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