Jacob Margolis True Grit Resources Ltd.

Transcription

1 Discovery of Gold Beneath a Barren Opaline Cap at Painted Hills, NW Nevada, and the Association of Gold with Molybdenum in a Low-Sulfidation Epithermal System Jacob Margolis True Grit Resources Ltd. Don t be model driven! E.S. Cheney Eric, 1986

2 Middle Miocene, Low-Sulfidation, Epithermal Au-Ag BuckskinNational Hog Ranch Bl ac kr oc k St ru ct u ra lb ou nd ar y Painted Hills Sleeper Sandman Mountain View Hycroft Rosebud Florida Canyon 25 Miles Wildcat Seven Troughs Goldbanks

3 Main opal stockwork zone Opal Veins Mine Gulley Ts Tcr Opal replacements in Ts Tt South Silicified Fault Vent 500m

4 Argillized Felsic Volcaniclastic Sequence Ts Tt 3 ppm Hg 24 ppm Sb 13 ppm As no Au or Mo

5 Felsic Volcaniclastic Sequence

6 Upper Sandstone Looking NE stratiform opal Ts Tt

7 Upper Sandstone Looking NE stratiform opal Ts Tt

8 Felsic Pyroclastic Vent 24 ppm As 102 ppm Sb 14.5 ppm Hg no Au, Mo

9 Felsic Pyroclastic Vent 14 Ma Whole-rock K-Ar (Hulen, 1979)

10 Main opal stockwork zone Opal Veins Mine Gulley Ts Tcr Opal replacements in Ts Tt South Silicified Fault Dome 500m

11 Opal Veins

12 South Silicified Fault

13 Rock-chips Maximum Values ppb ppm: Rock Type Au As Sb Hg Mo Opal replacement zones in Ts Opal veins Hematitic argillized Tt Silicified flow dome North dike at range front South silicified fault >100 - Pyritic chalcedonic silica float from mine gulley > Values considered anomalous

14 Low-Sulfidation Geologic Exploration Model advanced-argillic alt. acidic water Water Table Silicification (opal) sinter Zone 1 Steam-heated zone Hg, S o, no or trace Au opaline silica grading down to chalcedony sinter at water table volcanics basement or more volcanics Argillic-silicic-adularia alt. Low-grade Au blanket with fracture-control, local stkwks High-grade veins in zone of focused episodic boiling Zone 2 Zone 3 Stratiform low-grade Au replacement system Permeabilty/aquifer control Tuffs, volcaniclastics High-grade veins Focused along basement contact or in competent volcanic units quartz-adularia-calcite AgSe, low Pb-Zn boiling modified from Hedenquist et al. ( 2000)

15 Looking 015 South Silicified Fault Chalcedonic silicification Hg, As, Sb, no gold, no Mo Unaltered Ts base of oxidation Argillic Unaltered Tt 100ft Silicic PH alt ABSENT Argillic HK Argillic Mod. Silicic Hem-Kao oxidized argillic Strong Silicic Silicic mod Silicic strong Unaltered Ts Unaltered Tt Unaltered Tb Unalt/uncertain Unalt basalt Unalt tuff Unalt sandstone Tb PH ft 300ft Au ppm

16 Opal Veins Looking As-Mo PH0701 Target? Mo PH0703 No Mo Fewer silicic zones Lower Au 100ft HK Argillic 300ft Mod. Silicic Strong Silicic Unaltered Ts Unaltered Tt Unaltered Tb PH0704 Au ppm

17 Silicification and Veins 3: 1028ft 3: 1024ft 3: 449ft 1: 1021ft ppb Au ppm As ppm Sb ppm Hg ppm Mo

18 Silicification and Veins 3:1023ft 2: 932ft 1: 571ft 4: 1410ft no bladed cc, sug qz ppb Au ppm As ppm Sb ppm Hg ppm Mo

19 Silicification and Veins ppb Au ppm As ppm Sb ppm Hg ppm Mo

20 Gold Correlations (R values) PH0701 PH0702 PH0703 PH0704 Ag As Sb Cu Pb Zn Hg K Mo S Se Sn Te Tl U W

21 Molybdenum-Rich Veins ppm Au As Sb Hg Mo Vein separate: % and 72 ppm Tl

22 Jordisite py py 100µm 100µm 10µm

23 Conclusions 1. Gold discovered below barren opaline cap in previously untested LS epithermal system; validation of epithermal exploration model

24 Conclusions 1. Gold discovered below barren opaline cap in previously untested LS epithermal system; validation of epithermal exploration model 2. Need to be confident (more aggressive) in applying exploration models

25 Conclusions 1. Gold discovered below barren opaline cap in previously untested LS epithermal system; validation of epithermal exploration model 2. Need to be confident (more aggressive) in applying exploration models 3. System remains under-explored Boiling level deeper or lateral to the area tested Pediment untested

26 Conclusions 1. Gold discovered below barren opaline cap in previously untested LS epithermal system; validation of epithermal exploration model 2. Need to be confident (more aggressive) in applying exploration models 3. System remains under-explored Boiling level deeper or lateral to the area tested Pediment untested 4. Au-Mo association Au:Mo correlation Possible metal source from felsic magmatism