Marengo Photo Gallery

Marengo (Au/Cu/Ag)

Rockfire is seeking expressions of interest from Parties to establish a Farm-in and Joint Venture for the Marengo Project. Marengo is a highly-prospective project, however Rockfire Management wishes to focus financial and human resources on its Molaoi zinc project in Greece. Rockfire is looking to advance Marengo by bringing in a capable partner to explore on behalf of the joint venture.

The Marengo Gold/Copper/Silver Project is a structurally-controlled, high-level Intrusion Related Gold System (IRGS) incorporating the entire historical Marengo Goldfield. Located in central Queensland and lying within a high-density belt of porphyry copper deposits, Marengo provides Rockfire opportunity to discover high-grade gold and large-scale porphyry copper deposits.

Gold was first discovered at Marengo in the late 1870’s and hosts thirty-seven (37) historical gold diggings. Hand-picked production is recorded as averaging 2oz/t Au (62g/t Au). During the height of its mining days, more than 200 people lived at Marengo working the many diggings and shafts in the area.

In 1921, the area was being explored by individuals and a record by a Mr. Moreton noted that all the small gullies were said to carry gold and that one of his hard rock samples contained 29 dwts per ton (46.5g/t Au).

During 1935, whilst prospecting in the area, a Mr. Ridgeway noted that rock sampling of a large hill of quartz (now known as Westwood Hill) returned an average grade of 10 dwts per ton (15.5g/t Au).

Throughout the tenement, strongly anomalous geochemistry has been detected with rock samples up to 149g/t Au, 17% Cu and 78g/t Ag.

In 2018, Rockfire completed geological and structural mapping and two phases of Induced Polarisation geophysics. An initial Gradient Array survey highlighted potential for sulphides in the immediate vicinity of One Mile Mountain and a follow-up Dipole-Dipole survey indicated sulphide potential approximately 80m beneath One Mile Mountain. Subsequent drilling of 10 reverse circulation holes for a total of 940m returned mixed results with One Mile Mountain returning disappointing results and Homeward Bound returning 4m @ 2.1g/t Au, 1m @ 1.9g/t Au and 1m @ 1.6g/t Au (from 27m deep).

Prospect Appraisals

Marengo is related to numerous, parallel, north west/south east trending faults which intersect a zone of north/south trending fault zones. The intersection of these faults creates a highly fractured and rotated structural environment resulting in increased fluid percolation.

Marengo is vastly under-explored. Although numerous copper and gold occurrences are mapped and the tenement contains abundant structural targets, there has been limited focussed exploration work completed within the Rockfire tenement area. Potential exists to identify structurally-controlled, intrusion-related copper and gold deposits occurring at the margins of the monzonites and granites mapped within the tenement.

The first concentrated exploration effort within the tenement was by Intek Services when they acquired the tenement in 1981. Intek undertook rock chip sampling of the individual reefs, as well as semi-regional stream sediment sampling which focused on One Mile Mountain and the Three Brothers areas. Most rock samples ranged between 2.0g/t Au and 17.4g/t Au.

In 1987, Xenolith Gold acquired the tenement and undertook initial rock sampling which identified high-grade gold and silver at the workings including;

• Flat Reef – average assays of 5.4g/t Au and 50.2g/t Ag
• Westwood – average assays of 2.1g/t Au and 9.0g/t Ag
• Homeward Bound – assays range from 0.3g/t – 6.7g/t Au and 1.0g/t – 92g/t Ag.
• Manchester Reef – assays range from 0.02g/t – 60g/t Au and 4.0g/t – 100g/t Ag.

Of interest is the lack of copper analysis by Xenolith, given that the rocks are described as “copper-stained gossanous material”.

Xenolith continued its exploration in 1988 by drilling 39 RC drill holes. These holes were drilled at the following locations;

• Homeward Bound – 5 holes (PD1 – PD5).
• Toomeys – 4 holes (PD6, 7, 8, 8A).
• Westward – 8 holes (PD9 – PD16).
• Flat Reef – 22 holes (PD17 – PD39).

Results from this drilling ranged between 0.62g/t and 1.13g/t Au. Many of the holes terminated prematurely due to caving, water and shafts or adits. Most of the holes were drilled vertical which is not considered appropriate in an epithermal/structural/fault-hosted setting. The drilling recoveries were very poor (down to 6%) and full recovery using modern drilling equipment is expected to increase gold values materially.

THREE WAYS

The Three Ways historical mines contain high-grade gold in rock samples (e.g., 6.9g/t Au, 10.0g/t Au and 7.0g/t Au), as well as 149.80g/t Au which represents the highest value obtained to date from the Marengo Project. Three Ways is situated on east-west trending structures within an altered diorite and hosts an Aplite dyke and north-west trending quartz veins. Owing to the extremely high-grade rock samples, its proximity to intersecting east-west and north-west trending faults and subsequent intrusion/alteration, the Three Ways Prospect is considered a high-priority target.

WESTWOOD

The Westwood historical mines contain high-grade gold in rock samples, with results including 11.8g/t Au, 20.7g/t Au, 17.0g/t Au, 15.0g/t Au and 11.0g/t Au. Eight open hole percussion RC drill holes were completed in 1989 by Xenolith at Westwood. Each hole (PD09 to PD16) was drilled vertical and only sampled sporadically. From a total of 150m drilled, only 26m were assayed. Westwood is located in an altered diorite with east-west trending structures and quartz veining. Westwood is considered a high-priority target because of the presence of altered diorite, high levels of structural faulting and high-grade rock samples. 

FLAT REEF

The Flat Reef historical mines contain high-grade gold in rock samples (e.g., 16.2g/t Au, 50.0g/t Au 18.4g/t Au, 12.8g/t Au and 10.4g/t Au). Costeaning was completed in 1988, however there is no mention in the literature of the length of each costean, the length of each individual costean sample, type of costean sample collected, nor a map clearly identifying the location of each costean. From assumed individual sample lengths of 1m, costeaning returned an interval of 12m @ 6.06g/t Au. Twenty-two (22) open hole percussion RC drill holes (PD17 – PD22, & PD 24 – PD39) were completed in 1989. Each hole (PD09 to PD16) was drilled vertically and sparsely sampled (of 487m drilled, only 127m were actually assayed). The drill logs report very low sample recoveries down to as little as 6%. This prospect is considered to be a high priority target due to the poor recoveries and the high-grade rock and costean samples.

HOMEWARD BOUND

Homeward Bound contains high-grade gold in rock samples of 23.5g/t Au, 6.7g/t Au and 8.4g/t Au. Five (5) open hole percussion RC drill holes were completed in 1989 by Xenolith at Homeward Bound. Each hole (PD01 to PD05) was only sporadically sampled (of 200m drilled, only 26m were submitted for analysis). The drill logs report very low sample recoveries down to as little as 30%.

TOOMEYS

The Toomey’s mines contain high-grade gold in rock samples including 4.4g/t Au and 1.4g/t Au. Four (4) open hole percussion RC drill holes were completed in 1989. Each hole (PD06 to PD08a) was only sporadically sampled (of 141m drilled, only 12m were actually analysed). The drill logs report very low sample recoveries down to as little as 45%.

NEW REEF

The New Reef was discovered by regional geochemical sampling of historical workings which were not recorded in the old literature. Rock sampling (25g/t Au) and costeaning at New Reef during 1988 proved very encouraging. There is no mention in the literature of the length of each costean, the length of each individual costean sample, type of costean sample collected, nor a map clearly identifying the location of each costean. From assumed individual sample lengths of 1m, Costean 1 intersected 12m @ 0.91g/t Au, Costean 2 encountered 10m @ 1.22 g/t Au and Costean 3 returned 9m @ 1.03g/t Au. New Reef provides an excellent exploration target for further work.

BEE HILL

The Bee Hill workings are situated in the western part of the Marengo Tenement. Surface rock samples returned high-grade gold of 7.1g/t Au, 4.0g/t Au, and 2.3g/t Au. Bee Hill is located in a zone of north-west trending faults. No drilling or costeaning has been completed at the Bee Hill prospect, which is considered a medium level target.

BEE CREEK

The Bee Creek workings are situated in the western part of the Marengo Tenement (south-east of Bee Hill). Historical rock samples returned high-grade gold including 29.9g/t Au, 10.7g/t Au, 11.1g/t Au, 3.3g/t Au, 4.4g/t Au, 8.2g/t Au and 22.4g/t Au. Bee Creek is located in a zone of north-west trending faults. Should Bee Hill and Bee Creek Prospects prove to form a single, cohesive mineralised system, then this would result in a mineralised corridor in excess of 5km strike. No drilling or costeaning has been completed at Bee Creek.

300-OUNCE PATCH

The 300-Ounce Patch historical workings are situated in the central part of the Marengo Tenement. Surface rock samples have returned high-grade gold results which include 5.0g/t Au, 11.8g/t Au, 4.0g/t Au, 18.9g/t Au and 18.0g/t Au. No drilling or costeaning has been completed at 300-Ounce Patch.

OTHER PROSPECTS

Three additional historical mines returned high-grade gold in rock samples; Frankie’s (16.6g/t Au), Sulphide Shaft (14.0g/t Au, 8.6g/t Au) and Hill top (17.4g/t Au, 25.2g/t Au and 5.5g/t Au). No drilling or costeaning has been completed at any of these prospects. They each occur in metasediments proximal to the intersection of east-west and north-west trending faults and provide opportunity for new discoveries for Rockfire.