Abstract
The Harlan property is a significant newly discovered sediment-hosted gold prospect within the Selwyn
Basin in east-central Yukon Territory. The property contains a kilometric-scale gold-arsenic-antimonymercury-bismuth anomaly within a thick sequence of Paleozoic Selwyn Basin shelf and off-shelf sedimentary stratigraphy intruded by mid-Cretaceous Tombstone Suite late stage quartz-feldsparporphyritic dykes. Two major mineralized zones have been defined: the WFM Zone, a thick package of strongly brecciated, silicified and argillically altered coarse clastic sediments overlain by a thrust-faulted argillite member; and the West Porphyry Zone, consisting of abundant mineralized and altered monzonitic dykes. Surface soil and talus fine sampling across the WFM Zone has defined a NNW trending 1,600m by
750m zone averaging greater than 300 ppb Au, with rock sample values to 6.5 gpt Au. Within this area, a core 400m x 300m area, called the “Vortex Zone”, returned an average value of 1.4 gpt Au from soil sampling. Surface sampling within the West Porphyry Zone has identified a broad anomalous area with gold in silt values up to 230 ppb and numerous rock ship samples returning over 1.0 gpt Au. No drilling has been done on the property to date. NovaGold plans detailed surface geological mapping, geochemical sampling, and geophysical surveys to refine drill targets for testing in the year 2000.
Location and Access
The Harlan Property, wholly owned by NovaGold Resources Inc, consists of 339 contiguous quartz mining claims (Cam 1-8, Harlan 1-331) covering a 70 square kilometre area measuring 10 by 7 kilometres. It is located roughly 150 kilometres NNE of Ross River, Yukon Territory centred at 63 o 14’ North latitude,
131 o 40’ West longitude on NTS Map Sheets 105O/4 and 105O/5. Access is by helicopter from the serviceable Plata airstrip 35 kilometres to the north-west. A winter road extends from the seasonally maintained North Canol Road to within 10 kilometres of the north property margin.
History and Previous Work
In 1997, Viceroy Exploration (Canada), Inc. identified a large visible sediment-hosted arsenical alteration zone and associated limonitic dikes covering a small mountain, and staked the CAM claims to cover these features. Following receipt of a value of 771 ppb Au/ 1,400m (open to the south-east) from soil sampling across this zone, as well as a value of 1.26 gpt Au from rock sampling of a dyke 2.5 kilometres to the west, the HARLAN 1-331claims were added. Exploration later in 1997 and 1998 delineated a very pronounced kilometric-scale gold anomaly averaging greater than 300 ppb Au across the alteration zone, now called the
“WFM Zone”. Also, abundant mineralised WNW trending dykes occurring up to 2.5 kilometres to the west within the “West Porphyry Zone” were delineated, returning values to 0.86 gpt Au/ 20.8 metres from channel sampling. Detailed stream silt sampling just south of the West Porphyry Zone delineated a 0.5 square kilometre area comprised of gold values exceeding 100 ppb Au, with abundant values exceeding
200 ppb Au.
No mineralised occurrences were delineated prior to the 1997 discovery by Viceroy; this is a newly recognised prospect.
1999 Program
In early 1999, 100 per cent interest of the property was transferred to NovaGold Resources Inc, which performed geological mapping and limited selective rock grab and chip sampling. The program succeeded in defining mineralized sediment-hosted zones stratigraphically underlying the previously accepted base of the WFM Zone, as well as auriferous breccia zones within this zone. Within the West Porphyry Zone, an
8-10m wide monzonitic dyke consistently returning values greater than 1.0 gpt Au was discovered in 1999.

Fluid inclusion studies and detailed thin section analysis of numerous Harlan Property samples, together with gold and 32 element ICP analysis are ongoing. (Add to report if returned in time)
Regional Geology
The Harlan Property is situated within the Selwyn Basin, consisting of a broad package of Paleozoic sediments extending ESE from the Alaskan border to the Yukon-NWT border, north of the NW-SE trending Tintina Fault Zone. The Selwyn Basin consists of shallow shelf to off-shelf marine clastic and chemical sediments, as well as basinal clastic sediments derived from the Ancient North American
Platform to the north-east. Age of deposition ranges from Late PreCambrian to Triassic. The Selwyn Basin consists of numerous stratigraphic groups, including: the Hyland Group, consisting of coarse clastic “grits’ and phyllites formed during the late PreCambrian to early Cambrian Periods; the Ordovician to Early
Devonian Road River Group, consisting of chert, black chert to argillite and calcareous siltstone; immediately followed by deposition of the Devono-Mississippian Earn Group, consisting of chert-pebble conglomerate, greywacke and shale.
At least two episodes of rifting have occurred; the first during deposition of Hyland Group sediments, the second during deposition of Earn Group sediments. These rift zones often host poorly sorted coarse clastic sediments, such as debris flows or turbidite horizons. Several episodes of continental uplift have led to periods of increased erosion and resultant continental margin and miogeosynclinal deposition, resulting in formation of sequences of comparatively high energy shallow-water sediments, often coarsely grained and variable calcareous. These sequences, such as Hyland Group coarse clastic “grit” units, and Earn Group chert-pebble-conglomerate members, are separated by strata formed under more quiet, deeper water conditions, such as Road River Group chert and fine clastic sediments.
The Selwyn basin has been intruded by the Mid-Cretaceous Tombstone-Tungsten Plutonic Suite, forming an ESE trending belt of intrusives extending from the Fairbanks, Alaska area to the Yukon-NWT border.
Composition ranges from dioritic to granitic, most commonly monzonitic to quartz-monzonitic with feldspar and quartz-feldspar porphyritic phases common to more evolved intrusive phases and dykes.
These intrusives, due to high content of volatiles concentrated during magmatic fractionation, have very favourable physio-chemical charasteristics for formation of iontrusive hosted and related gold deposits.
In the Harlan Property area several WNW trending thrust faults, reactivated as dextral strike-slip faults, have caused imbrication of Selwyn Basin stratigraphy throughout the Mesozoic Era. Numerous such
“transpressional” faults associated with fairly intense, locally overturned folding, comprise a broad deformation belt referred to as the “Gold River Fold Belt”. Stratigraphy is dominated by an ESE trending imbricated assemblage of Earn Group siliclastics with lesser Road River Group chert, siltstone, argillite and limestone and Gull Lake Formation siliceous shale and siltstone. Several Tombstone Suite quartzmonzonite to syenite stocks occur within twenty kilometres of the property.
Property Geology
The Harlan Property is underlain by a thick sequence of Earn Group chert pebble conglomerate, sandstone and greywacke, with lesser shale to siltstone members. Several roughly east-southeast trending units of
Road River Group shale to siltstone, and graphitic argillite units extend across the property. Contacts are indicated by ESE trending, moderately south dipping thrust faults causing imbrication of Earn and Road
River Group stratigraphy within a compressional regime. This has been overprinted by a NNE-SSW trending lineation manifested by drainages across the property, as well as a third N-S trending lineation.
The central area of the Harlan Property is covered by a sequence of Road River Group graphitic argillite thrust against an underlying thick package of mineralized Earn Group chert pebble conglomerate with lesser greywacke and sandstone; this is the “WFM Zone”. The NW-SE trending, SW dipping thrust fault contact overlies the conglomerate. Within the WFM Zone, the Earn Group sediments have undergone strong argillic alteration and silicification, and display multi-episodic fine quartz veining and stockwork

development, interstitial and replacement style quartz-arsenopyrite mineralization, and widespread disseminated fine to medium grained pyrite and pyrite boxwork. Elsewhere, similar unaltered chert pebble conglomerate has a strongly calcareous matrix, suggesting a similar original matrix for the WFM Zone conglomerates. A feldspar porphyritic stock, perhaps the heat source for the alteration, occurs roughly 300 metres to the south.
Geological mapping suggests that the WFM Zone is a strongly altered, mineralized tabular Earn Group chert pebble conglomerate member, at least 200 metres thick, overlain by the imbricated graphitic argillite member. The base consists of a ESE trending, SW dipping strongly foliated monzonitic dyke along a thrust fault. This contact separates strongly altered mineralized chert pebble conglomerate from weakly silicified chert pebble conglomerate with moderate quartz stockwork development along the footwall. Alteration and mineralization decrease towards the top of the tabular unit, along the footwall of the thrusted argillite.
A “window” of Earn Group sediments, associated with anomalous gold in soil values west of the upper thrust contact, and an occurrence of WFM-style float within graphitic argillite 600 metres to the west of the main zone, suggests that the WFM Zone extends considerably to the west beneath the overlying argillite.
Sampling of this float returned anomalous gold values; silt sampling returned values to 85 ppb Au.
A suite of late-stage Cretaceous altered quartz-monzonite dikes extends WNW across north-central areas of the property from the WFM Zone to the West Porphyry Zone. These are most abundant within a 3 kilometre long, 0.75 km wide zone linking the WFM and West Porphyry Zones, likely emplaced within a broad zone of structural preparation. Within the WFM Zone area, dykes have variable orientations reflecting paleolineaments, and form localized “dyke swarms” within graphitic argillite just to the west.
Dykes within in the West Porphyry Zone extend mostly WNW, particularly along northern margins of the broad graphitic argillite unit in contact with chert pebble conglomerate to the north.
In the southern WFM zone an area of abundant rubblecrop of explosive breccia occurs, associated with a marked increase in gold in soil values centred on a 1997 sample returning 10.42 gpt Au. This is the
“Vortex Zone” which has been interpreted as an explosive breccia pipe. Clasts are chiefly of graphitic argillite; however clasts of altered dyke material are common, clearly indicating that the explosive event postdated dyke emplacement.
Mineralogy
Further soil sampling across the WFM Zone returned values to 453 ppb Au/ 800 metres; rock sampling returned values to 2.24 gpt Au. Soil sampling in 1998 returned values to 7,400 ppb Au and defined the
“Vortex Zone”, a 400m by 300m sub-zone averaging 1.4 gpt Au centred at the 10.42 gpt Au anomaly. An intersection returning 764 ppb Au/ 600m was also defined in this area, as well as several other significant sub-zones. Rock sampling returned anomalous values to 880 ppb Au, with a value of 4.64 gpt Au returned from select grab sampling of quartz-arsenopyrite talus. Gold is associated with strongly variable silver, arsenic and bismuth values, as well as anomalous mercury, antimony and lead.
A value of 655 ppb Au/ 1.2m from silicified conglomerate associated with fine disseminated pyrite, was returned from this material roughly 50m stratigraphically beneath this thrust, suggesting mineralization extends into the footwall. Exploration in this area by NovaGold in 1999 showed that this belongs to a zone of weakly limonitic, strongly silicified finely pyritic sediments at least 10m thick. Sampling of similar material roughly repeated the earlier values. A sample of brecciated arsenopyrite in a baritic matrix returned 6.5 gpt Au. A value of 880 ppb Au/ 3m was returned from sericitic dyke material 350m east of the
Vortex Zone; this may represent a significant zone east of the “main” WFM Zone.
Results of rock and soil sampling failed to explain the relationship between soil values that are consistently higher than rock values. This may be caused by association of gold with unexposed, strongly altered, weathered portions of the rock, either as wide recessively weathered zones, or as selectively altered portions of the rock, such as veins, fracture zones, clasts, etc. Soil profile sampling at several locations, at depths from 10 to 60 centimetres, returned consistently higher gold values from soil than overlying rubble.
This suggests gold enrichment is widespread, rather than eminating from localized sources or occurring as residual mineralization following erosion, and that the rubblecrop represents resistive, possibly less

mineralized members of the zone. Detailed mapping of the zone suggests a series of strongly silicified resistive zones, likely structurally controlled, may act as “aquicludes” and account for most of the competent rubblecrop along the hill. These resistive zones, returning values to 880 ppb Au, may comprise a minority of the hill’s rock mass; the rest may be underlain by recessive zones that may be the source of most of the gold in soil anomalies.
Rock chip sampling across the West Porphyry Zone at the 1.26 gpt Au anomaly returned 0.86 gpt Au/
20.8m, with values of 0.56 gpt Au/ 4.2m and 0.48 gpt Au/ 3.5m returned from nearby sampling. Gold in the main dyke is associated with weakly elevated mercury, arsenic, and antimony, with surprisingly low silver and bismuth values; however, certain other dykes have strongly anomalous mercury signatures.
Anomalous values to 1.16 gpt Au were returned from similar dykes across 2.5 square kilometres. Silt sampling to the south-east returned values commonly greater than 200 ppb Au with pathfinder signatures more typical of the WFM Zone except for low bismuth values. These anomalies have not been adequately explained, although dykes appear to be abundant in this area. Chip sampling in 1999 by NovaGold
Resources across a newly identified silicified monzonite dike just east of the main dyke returned a value of
1.08 gpt Au/ 1.3m.
The dyke hosted mineralization and WFM Zone mineralization are believed to have a common source; these zones may occupy a major ESE trending paleolineament such as an ancient rift zone. Anomalous geochemical values occur across roughly ten square kilometres. The dimensions of this system suggest the
Harlan Property has the potential to host a “world class” gold deposit.
Conclusion
The Harlan Property represents a potential new bulk tonnage gold deposit model type for the Yukon.
Sediment-hosted gold mineralization occurs within the WFM Zone, a thick tabular unit of fractured to brecciated reactive Earn Group chert-pebble conglomerate and coarse clastic sediments proximal to a quartz-monzonite stock inferred from abundant rubblecrop to the south. The surface exposure of the WFM
Zone is associated with a kilometric-scale gold in soil anomaly averaging greater than 300 ppb Au, associated with anomalous silver, arsenic, antimony, mercury and bismuth. Although late stage dykes occur across the WFM, the main target is the roughly 200 metre thick package of quartz stockworked, silicified and argillically altered sediments. The presence of structural corridors and regions of strongly decrepitated material suggest that gold mineralization, although widespread, may be intensified towards ore grade in certain areas.
The footwall of the WFM Zone appears to be a south-west dipping thrust fault, indicating a compressional setting providing abundant corridors for fluid movement. Brecciation has allowed mineralized fluids to penetrate the locally reactive coarse clastics. This package is capped by a thrusted block of Road River
Group graphitic argillite, extending to the west. Exposures of WFM-style float within the argillite up-ice from the exposed WFM Zone suggest the zone continues beneath the overlying member considerably to the west. Abundant gold in silt anomalies just south-east of the “West Porphyry Zone” 2.5 kilometres to the west have similar pathfinder signatures to the WFM Zone. Mineralized dykes comprising the West
Porphyry Zone have markedly different, although variable, pathfinder signatures, suggesting the silt anomalies may not represent an intrusive-hosted target. These dykes, returning values to 0.86 gpt Au/
20.8metres, represent a secondary, although significant target within the Harlan Property.