Cardero sampling outlines new Cu target at Zonia
2018-02-01 09:13 ET - News Release
Mr. Stuart Ross reports
CARDERO ROCK SAMPLING GENERATES NEW PORPHYRY TARGET NORTHEAST OF THE ZONIA COPPER OXIDE DEPOSIT
Cardero Resource Corp. has received positive surface exploration results for the company's Zonia copper oxide project, located in Yavapai county, Arizona, United States. Rock geochemical sampling on a 150-metre-spaced grid over most of the claim block has generated a new porphyry copper target based on coincident anomalous copper, molybdenum and manganese. The 2,500-by-1,000-metre anomaly occurs northeast of the drill-defined Zonia copper oxide deposit, and shares characteristics of its geochemical footprint.
"We are extremely pleased to have generated such a large target adjacent to the drill-defined copper oxide resource, and in an area that would not interfere with the conceptual mine design. Once the current geophysical survey is complete, we hope to have a compelling drill target, one that could add significant upside to the mineral resources at Zonia," says Stuart Ross, chief executive officer of the company.
Cardero is currently completing a 28-line-kilometre IP survey over the Zonia and neighbouring Silver Queen properties (see news release 16-06), utilizing 200-metre-spaced dipoles.
Northeast porphyry target
Coincident areas of elevated molybdenum (Mo) and copper (Cu) values with depressed manganese (Mn) values is a classic geochemical signature of porphyry copper mineralization. Copper values are also anomalous, but copper is not as reliable as the other metals due to its solubility in the weathering profile. The overlapping anomalies suggest a porphyry copper target size on the order of 2,500 by 1,000 metres. The same quartz-feldspar porphyry dacite that hosts the Zonia copper oxide resource (see NR17-08) underlies the anomaly. The anomaly marks a break in the northeast trend of the mineralization, with a narrow southern "tail" that opens northward to a broader northeast trend. The anomaly is truncated at the north end by younger, postmineral cover rocks (Gila conglomerate, alluvium and Tertiary basalt). The east margin of the anomaly contains some narrow high-grade copper-bearing structures in the historical Copper Crown mine workings, with associated intense epidote alteration.
Current exploration
The entire area covered by the rock geochemical grid will be covered by the continuing IP survey. Once completed within the next few weeks, these additional data should further delineate subsurface mineralization as well as depth to sulphides (depth of oxidation) under the large Cu-Mo-Mn geochemical anomaly northeast of the Zonia deposit.
Additional 150-metre-spaced rock sampling is planned for the open pit area and southwest of the pit, where more detail is required to close off the anomalies.
Zonia copper oxide deposit
The Zonia copper oxide project has been held under private ownership for almost 100 years and has undergone comprehensive exploration, metallurgical studies and mine development planning. The majority of the mineralized area was prestripped during previous open-pit mining operations at Zonia in 1966, as 17 million tons were mined with seven million tons stacked on heap leach pads, producing cement copper up till 1975. The property has been drill tested with almost 700 drill holes (60,000 metres). This high-density drilling covers 30 per cent of the property and defines the current resource estimate, reducing technical risk on the deposit.
The Zonia copper deposit has a northeasterly strike length of about 2,400 m (8,000 feet) and horizontal width varies from 60 m (200 ft) to 460 m (1,500 ft). The deposit consists of multiple mineralized zones that dip at various angles to the northwest. The zones are generally in the order of 200 ft (60 m) wide and commonly occur in subparallel groups of three or more. Most of the deposit has been drilled to depths of 120 m (400 ft) or less. Deposit highlights include:
- Measured and indicated resources of 76.8 million short tons grading 0.33 per cent copper containing 510 million pounds of copper (0.2-per-cent copper cut-off grade);
- Inferred resources of 27.2 million short tons grading 0.28 per cent copper containing 154.6 million pounds of copper (0.2-per-cent copper cut-off grade);
- Low strip ratio of 1:1 waste to mineralized material in base case.
Sampling procedures and quality assurance and quality control
The work program at Zonia was designed by John Drobe, PGeo, the company's chief geologist, with the fieldwork conducted by Discovery Consultants, of Vernon, B.C. Due to a lack of consistent soil cover over the project, composite rock samples were collected by shovel from 10-to-25-centimetre depth over a roughly one-metre-square area at each station, and the locations marked with flagging and aluminum tags hung from the nearest vegetation. Samples were placed in woven Sentry brand 7 by 12.5-inch Olefin sample bags, which were sealed, transported and dropped off directly at ALS Minerals laboratories in Tucson, Ariz., by Discovery personnel. The samples were dried at high temperature (method DRY-21), crushed, pulverized (methods CRU-31, SPL-21, PUL-31), and then analyzed by ICP-AES for 35 elements (method ME-ICP41) with gold determined by 30 g fire assay and atomic absorption finish (method Au-AA23).
This sampling program did not include a comprehensive QA/QC program; however, ALS Minerals is an ISO 9002 registered laboratory and inserted blanks, standards and duplicates following their QA/QC protocol. These additional samples returned satisfactory values.
Qualified person
John Drobe, PGeo, Cardero's chief geologist and a qualified person as defined by National Instrument 43-101, has reviewed the scientific information that forms the basis for this news release, and has approved the disclosure herein. Mr. Drobe is not independent of the company as he is an officer, a shareholder and hold incentive stock options.