- Management of Patrimonial Properties
- NRDC and Grandia MRF Services Corp. Joint Venture Agreement on Landfill Solid Waste Management
PROJECT: NRDC-JB Mines Joint Operating Agreement (JOA)
PROJECT DURATION: 25 years
- Exploration, Monitoring & Development
- Collection of Bullion Shares
LOCATION and ACCESSIBILITY
- · Contract Area: 452.29 has.
- · Elevation: 600 meters above sea level
- · Location: Mount Diwata, Brgy Diwalwal, Monkayo, Compostela Valley
The designated Small Scale Mining Area under DENR AO 66 is within 7°48'30" to 7°50'00" N latitude and 126°10'30" to 126°12'00" E longitude with a total area of 729 hectares.
The JOA mining area can be reached from Davao City thru the Davao-Surigao Highway to Monkayo, which is about 120 kms; thence eastward from Monkayo via a 22-km unpaved and rough barangay/logging road accessible only with 4-wheel drive vehicles.
The area is largely underlain by volcanic sequence made up of volcaniclastics, andesitic volcanic flows, volcanic breccias, and pyroclastics with minor interbeds of sandstone, shale and mudstone. Andesite porphyry and hornblende andesite porphyry intrude this sequence at the northern and southern portions. At the southeast portion, overlying this volcanic sequence is a massive and coralline limestone formation.
The Mineral Reservation is host to the Diwalwal gold vein systems of the Diwata Gold Project, Buenas-Tinago and Balite. These are gold-bearing fissure/breccia veins with massive to sheared, translucent, and dirty white to greenish gray, quartz-calcite and calcite-rich zones. The two vein systems are parallel, about 900m apart, and hosted in volcaniclastics, andesitic volcanic flows and pyroclastics.
Three (3) areas below-stated are currently being explored and developed for its potential, namely;
1. Buenas-Tinago Vein
The Buenas- Tinago Vein trends E-W to N45°E and dips 45°-55° to the south. It is truncated by a series of sub-parallel NNE trending strike-slip faults that resulted into an en-echelon vein pattern. The vein consists of white, massive to brecciated, sugary, crystalline, vuggy, crustiform and colloform banded quartz-calcite with slivers of chloritized volcanic host rock. It has widths of 1 to 4 meters with a measured strike length of 925 meters and vertical extent of 254 m from elevation 1000 mast down to 746 masl. It has an average gold grade of 10.93 gpt. The vein system is open-ended to the Northeast and still persists below 746 masl.
2. Balite Vein
The Balite vein trends E-W to N55°E and dips steeply to the south. The vein ranges in width from 2.5 to 6m and consists of pyritic, white, massive, sugary, crystalline, vuggy and colloform quartz-calcite. Balite vein has a measured strike length of 1.2km and a vertical extent of 450m from elevation 970 down to 525masl. Above L-600 this vein system flares-up, bifurcates, splays and horsetails upward with intervening flexures or dilational jogs, which are usually the loci for bonanza zones. Down-dip at L-570, it forms into a single zone. It has an average gold grade of 8.0 to 9.6 gpt.
3. Bar-Down Area
Currently no activity is being conducted and was totally shut down brought about by the series of disaster that affected countless miners.
PROSPECTS (Copper, Silver and Gold)
The Diwalwal gold vein systems are surrounded by copper, silver and gold prospects like Upper Ulip/Matangad Copper-Gold Prospect to the northwest, Mabatas/Higanteng Bato Copper-Gold Prospect the southwest, the Pagasa/Paraiso Gold Prospect to the north, Simulao Gold Prospect to the east, and Mapaso/Letter V/Bermuda Gold Prospects to the south.
Upper Ulip/Matangad Copper-Silver-Gold Prospect
The Upper Ulip/Matangad Cu-Au Prospect is located 3 kms northwest of Diwalwal. It is defined by a north-south trending 700 meter by 2 km zone with sporadic to extensive quartz stockworks and a possible copper deposit at depth. Quartz veinings and stockworklngs are found on rock outcrops along Upper Ulip and Matangad rivers. Quartz-calcite veinlets have visible copper minerals such as chalcopyrite and bornite. The host rock in the area is chloritic and pyritic andesite porphyry. Malachite and azurite stainings are present on the outcrops in the creek and on the walls of abandoned and active adits in the area. The copper values from the channel cuts ranged up to 0.97% Cu with minimal gold values less than 0.2 ppm. Point samples have copper values of 2.2 to 4.3% and gold values of 0.08 to 0.15 ppm.
Quartz-calcite veinings in the area ranged from 0.5 to 2.7 m in width and trend N-S to NNW and dips 45-85 to the east and west. These quartz veins are white to grey, massive to brecciated, with rhodochrosite, epidote, pyrite, chalcopyrite, sphalerite, bornite and gray silicified, pyritized inclusions. A 2.2 m wide strongly gougy, pyritized-chloritized zone with grey pyritic quartz inclusion has assayed 5.6 ppm Au and 162.18 ppm Cu.
Mabatas I Higanteng Bato Copper-Silver-Gold Prospect
The Mabatas/Higanteng Bato Copper-Gold Prospect is located 3kms southwest of Diwalwal. It is defined by a 2.7 km x 3.6 km zone comprising of widespread advanced argillic alteration with associated silica cap/feeder zone-remnants underlain by altered/mineralized hydrothermal breccias in places.Massive silicified outcrops called Higanteng Bato, Asawa HGB and Anak HGB are found to the east and south of the proposed dam. These outcrops are prominent, bare, and 3 to 50 m high above its argillic floor. The outcrops are clay-pyrite-quartz altered, light reddish-brownish at its outer weathered shell and grades into light grayish vuggy, silicified, highly pyritic, and brecciated. Channel-cut sample at the SW comer of the clay-pyrite-silica altered Higanteng Bato yielded up to 1.42 ppm Au and 155.5 ppm Cu.
Several outcrops of altered/mineralized hydrothermal breccias were found at the eastern, western and southern drainage systems of the prospect. The hydrothermal breccia outcrops were essentially silicified, pyritic and with clasts of sub-rounded to sub-angular silicified volcanic rock fragments with micro quartz vein lets, fine pyrite disseminations, minor chalcopyrite and bornite specks. Gold assays from the breccias, which are believed to have been pushed from mineralized porphyry Cu-Au deposit, yielded up to 7.233 ppm Au. Sporadic quartz-clay-pyrite alterations were. Mapped at the western, northern and southern drainage systems of the prospect.
Fregor GOLD Prospect
The Fregor Gold Prospect is located 2 kms to the west of Diwalwal. The Fregor Vein, as exposed on the road cut above the portal area showed a 1.4-2.0 m wide fault-vein zone, trends N300E and dips 45°NW towards the Military Camp. It pinches upward and swells downward, with densely developed highly sugary white quartz vein and veinlets along both walls. Fine pyrite dissemination and fault gouge along footwall and hanging wall are likewise noted. Muck grab samples from the Fregor Portal area yielded 1.79 to 7.90 ppm Au.
Pagasa I Paraiso Prospect
The Pagasa/Paraiso prospect is located 1 km to the north of the Diwalwal gold veins. At present, there are several small adits in the area and mining 0.50 to 2 m wide, creamy-white, drusy, pyritic quartz-calcite veins with clay, silicified rock inclusions, manganese oxides and limonite patches. Gold values from these adits ranged up to 4 gpt.
Simulao Gold Prospect
The Simulao Gold Prospect is located 2 kilometers east-northeast of Mt. Diwata. This has been the site of short-lived small-scale gold mining activities in 1987-1988. The gold occurs in pyriticcalcitic quartz veins. Pyrite occurs along the vein walls with rare malachite staining. These EW-ENE vein structures are probably the eastern extensions of Diwalwal vein systems.
Mapaso I Letter V/Bermuda Gold Prospect
These gold prospects are located 1 to 7 kms to the south of the Diwalwal gold deposits. Small scale mining activities are present in these areas. Based on the account of the locals, 0.5 to 2 m wide east-west trending quartz veins are being mined. These quartz veinings may be synchronous with the formation of the Diwalwal gold veins
- · Proposal as Sole Distribution of Chemical Reagents to abate environmental issues and proper monitoring (Letter Request of NRDC President-Chief, PNP)
- · Proposal as Sole Distribution of Explosives to abate public order and safety and proper monitoring (Letter Request of NRDC President-Chief, PNP)
- · Restoration of NRDC function to evaluate, monitor and approved Small Scale Mining Ore Sharing Agreements