Timberline Resources Corporation announced the results from two core holes from the 6,536-meter (m) 2021 drilling program at its 100%-controlled Eureka Project in Nevada. These include the final assays from drill hole BHSE-220C, a portion of which was previously reported, as well as a deeper core hole (BHSE-206C), drilled to the east of the WWZ to test a major induced polarization chargeability (IP) anomaly. The finalized assays from BHSE-220C significantly lengthened the previously reported mineralized interval and slightly improved the grade of the higher-grade portions.

The gold zone in this hole is summarized as below: 44.2m at 4.10 grams per tonne (g/t) gold from 140.8m depth, including; 22.9m at 6.24 g/t gold from 140.8m depth; and including; 12.2m at 9.18 g/t gold from 151.5m depth. BHSE-206C passed through extensive zones of alteration and low-grade mineralization, including abundant sulfides, carbonaceous material, and brecciation spanning approximately 350m, and identified the probable source of the IP anomaly. Portions of the hole were highly enriched in gold, including an interval of 30.5m of 0.41 g/t gold from 182.0m depth, including 7.6m of 1.04 g/t gold.

Significantly, the low-level gold mineralization was accompanied by strong silver content, including 18.3m that averaged 8.96 g/t from 153.0m depth. The hole included multiple additional zones of anomalous gold (86.9m at 0.16 g/t) and enriched silver, zinc, lead, molybdenum, and tungsten that appear to be associated with a propylitically-altered fine-grained quartz-feldspar intrusive rock (aplite). The geometry of the intrusion is impossible to determine yet, but the hole bottoms in at least 131 meters of that unit.

Geological Information from Testing the IP Anomaly: BHSE-206C, a core hole inclined -75° in a northeast direction (azimuth 050°), was designed to test the shallower portion of a large IP chargeability anomaly identified in 2021. The hole passed through a thick section of limestones ­ often highly fractured, brecciated, and variably oxidized - that are interpreted to be part of the Ordovician aged Antelope Valley formation. The degree of brecciation and alteration increased with depth as the limestone passed into a chaotic interval of interbedded sanded dolomite (altered) and fine grained felsic intrusive rock with abundant pyrite, which locally exceeds 10%.

Gold and silver content correlate with the extent of brecciation and presence of carbonaceous material. Where the dolomite becomes more massive, iron oxide veinlets increase and are associated with low levels of gold and silver mineralization. Pyrite increases as the drill hole passes into a light-gray to pale-green fine-grained quartz-feldspar intrusion, termed an aplite.

The aplite contains rare black biotite phenocrysts and is often cut by discontinuous thin, irregular quartz-potassium feldspar stockwork veinlets. The pyrite content of the aplite is locally high, and gold concentrations are enriched but only to anomalous levels (0.020 ­ 0.050 ppm). This sequence of altered sedimentary rocks cut by an intrusion with abundant pyrite, brecciation, carbonaceous material, and elevated gold and silver values provides an explanation for the IP anomaly that occupies this structural corridor.

Timberline has previously drilled similar lithologies, alteration and mineralization farther south in this area. In BHSE-206C, the alteration is more intense, the mineralization is higher grade, and the thickness of alteration and intrusive rocks is much greater. This style of alteration and mineralization is most likely associated with older Cretaceous-aged silver (gold) ­ lead -zinc mineralization that constitutes most of the historical mining in the Eureka District.

The Carlin-type gold that has been drilled at the Lookout, WWZ, and Oswego targets is likely younger and Eocene in age. Superimposed mineral systems are common and considered favorable in larger Carlin-type gold districts. The Ruby Hill ­ Archimedes Mine (i80 Gold Corp.), north of the Eureka Project, is an excellent example where millions of ounces of Carlin-type gold resources are reported to occur as overprinting earlier silver (gold) ­ lead ­ zinc mineralization.

Similarly, at least three generations of mineralization are reported in the giant Carlin Trend District. The multiple generations of mineralization may have used the same fluid pathways in the rocks; plus, the earlier stage alteration and mineralization may have enhanced the receptiveness of the host rocks to the later Carlin-type fluids. Timberline plans to explore the area of the huge IP anomaly that lies between the Lookout ­ WWZ Deposit and the Oswego Target which is ripe for additional discoveries.