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Nevada Gold Deposits & Districts - SITKA GOLD CORP - … · • Major Gold Districts: Laramide Age Geological Domes and Collapse Faults • Primary ore body controlling structures:

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Nevada Gold Deposits & Districts

• Carlin-type deposits >1-5Moz gold

• Massive Carlin-type gold Districts: N. Carlin, Cortez >190 Moz gold

• Open-pit and underground gold mines that cluster at structural intersections of oblique fold sets and collapse faults

• Devonian host rocks “lower plate”

• Consistent age of mineralization ~36-42 Ma.

Adobe Range District

• Newly Recognized NW Fold &Thrust belt that intersects and deforms an older NE Fold & Thrust belt: Dome Structure

• Lower plate window of Devonian host rocks

• Widespread Carlin-type Alteration and pathfinder geochemistry

• Simple Land Acquisition of BLM and Fee Land with 3-4 private land owners

The Adobe Range District: rare opportunity to consolidate an entire District Scale Carlin-type gold target play without competition

• Major Gold Districts: Laramide Age Geological Domes and Collapse Faults

• Primary ore body controlling structures: through-going NNW anticlines and oblique WNW anticlines within Devonian host rocks (Blue).

• NNW and WNW faults sympathetic to folding are critical ore fluid feeder structures.

• Structural and Temporal comparisons at the Adobe Range:

• NNW Anticlines oblique deforming NE and WNW anticlines & NNW tear faults,

• Devonian upper-host strata is exposed west of the immediate dome structure

North Carlin Trend (>150Moz) All three scales are equivalent

Adobe Project Cortez District (>40Moz)

~5km ~5km ~5km

Devonian Limestones “Lower Plate Window”

Dome Structures At Fold Intersections

Widespread Carlin-type Alteration Assemblages

• Jasperoid Development along fold limbs & crests

• Decalcification & Clay Alteration in Devonian Limestones

• Silicification & Hematitic alt. along Perm/Miss Unconformity and in Elko Formation Conglomerates

• Anomalous Arsenic

Carlin-type disseminated gold and gold-breccia targets:

1. Along the crest of NW-trending Anticline in favorable Devonian LPW host rocks at depth (estimate ~500m depth)

2. Largest deposits where NW fold intersect NE Folds & High-Angle NNW Tear Faults.

10km Long Central NW Fold Trend (~10,000 Acres)

.

• The Adobe LPW consists of Upper Devonian transitional limestone that is exposed over a large area a few miles southwest of Intercept’s main acquisition target area & dome structure

• Semi-massive detrital petroliferous limestone is variably inter-bedded with thinly laminated, argillaceous limestone and limey shale.

• These units are comparable and equivalent to the tops of the main gold host rocks at Carlin (Rodeo Creek Formation) and at Cortez (Horse Canyon Formation)

• Structural interpretations show these units occur at depth (<500m) beneath our targeted dome structure and wide spread alteration assemblages observed at surface.

Panoramic view of the Adobe Lower Plate Window

• The LPW consists of rounded, subdued hills that are dominated by decalcification and iron-oxide alteration that variably accompanies widespread argillic alteration of Devonian carbonates.

• The exposed buff tan clay and limonite assemblage is widespread for miles

• Upper Devonian interbedded limestone + argillite are selectively replaced by black jasperoid along major folds and/or thrust boundaries.

• Erosion resistant, tightly folded jasperoids exhibit multiple folding events

• The jasperoids are mineralized and commonly exhibit stockwork quartz veins and associated visible disseminated pyrite + arsenopyrite

Older, NE trending Garamendi Anticline looking southwest

Mesoscopic Parasitic Folds on steep limb of Garamendi Anticline

• A Permian/Mississippian Angular Unconformity occurs along the crest of the NW folded Mississippian Chainman Shale and the Permian-Triassic Adobe Syncline Basin.

• Folding is more intense in the Mississippian Chainman Formation and older strata than in Permian and Triassic rocks.

• Eocene Elko Formation is folded about the Major NW Anticline

• Age of folding is bracketed by an angular unconformity ~40.4 Ma

• Timing linked with age of all Carlin-type gold deposits 36-42 Ma

• Main Target: young, unhealed breccia related to the NW brittle folding within LPW stratigraphy located at depth along the NW fold trend within Dome Structure

South Dipping, pervasively altered and Arsenic-rich

Eocene Elko Formation

• Oil shale, conglomerate, limestone and tuff of the Elko Formation is folded “domed” indicating active local tectonism in the Middle Eocene

• Hydrothermal activity & alteration assemblages are concentrated along the NW fold axis trend and occupies all pre-existing structures and pervasively alters the Eocene Elko Fm.

• Silicification & Hematite/Limonite (+arsenic) are extensively developed in folded Eocene Elko Fm. on the SW flank of the project area

• Multiple areas mapped as “cherts” are actually jasperoids localized along stratigraphic horizons, unconformities, near tear faults and fold limbs

• Intense, pervasive decalcification, hematite -limonite alteration and jasperoids (+arsenic) occur along the folded Permian/Mississippian angular unconformity

• Other: base metal occurrences and small mines are present in Mississippian and Upper Plate rocks and represent the only publically reported mineralization in the area. This is analogous to the Pequop Range prior to the discovery of Long Canyon.

Jasperoid creates a ridge along the Perm/Miss unconformity for over two

miles in the exploration target area

Resistant Jasperoid

Silicified, Hematitic Elko Fm.

• Limited rock samples (n= 52) indicate Carlin-type pathfinders are anomalous in most altered rock types and structures where sampled at Adobe.

• Carlin-5 (As, Hg, Sb, Tl, S)

• The highest Arsenic values occur within silicified and hematite altered conglomerates of the Elko Formation and along the Perm/Miss Unconformity within the NW fold axis corridor

• Deformed, silicified, brecciated and argillically altered carbonates sampled within the Lower Plate Window exhibit trace concentrations of Carlin-type pathfinder elements