Five companies released drilling assays from projects in Mexico during the week. The most impressive results are the gold intercepts by Heliostar Metals at the Ana Paula project in Guerrero. The company reported results from holes aiming to better define the high-grade core of the deposit, which will aid in the planning of an underground mine. The deposit sits at the northern end of the Guerrero Gold Belt, and is one of those beasts hard to put in a cage, as it presents several mineralization styles. The Morelos platform sediments are intruded by a plagioclase-biotite porphyry that produced local hornfelsification and skarnification of the sedimentary rocks. Pyrite, marcasite and arsenopyrite are present as veinlets, stockworks and disseminations in these altered rocks, in breccias, and as narrow semi-massive sulfide replacements at intrusive contacts. A late low sulfidation epithermal veining stage with visible gold is also present in the deposit.

Discovery Silver’s Cordero project in Chihuaha is also one of these deposits not easily cajoled to only a mineralization style, with high grade intermediate sulfidation epithermal veins cutting through (overprinting?) disseminated Ag-Pb-Zn mineralization (earlier?) related to the intrusion of felsic laccoliths, dikes and sills into a calcareous sedimentary sequence, with skarn and carbonate replacement mineralization dominating parts of the deposit. A very broad classification would put Cordero as polymetallic intrusive related mineralization.

Prime Mining’s Los Reyes project and GR Silver Mining’s Plomosas property, both in Sinaloa, are intermediate sulfidation epithermal systems with a strong structural component. Avino Silver & Gold’s is finding stronger copper grades 800 m below the surface on the Avino vein, and is considering the probable presence of a porphyry copper setting at depth.