Reserves & Resources
The following information relates to gold resources and reserves identified at the Copperstone Mine in Arizona; American Bonanza's first 100% owned producing gold mine.
All reserves and resources shown in the tables above are filed in accordance with NI 43-101.
According to National Instrument 43-101 guidelines mineral resources that are not mineral reserves have not demonstrated economic viability. According to National Instrument 43-101 guidelines, inferred mineral resources are considered too speculative geologically to apply economic considerations that would enable them to be categorized as mineral reserves.
Mineral Resource Cutoff Grade Analysis
According to the Feasibility Study, the Measured, Indicated Mineral and Inferred Resources at various gold cutoff grades were also examined and are set out in the below tables:
Measured and Indicated Resources at Various Cut-Off Grades
Inferred Resources at Various Cut-Off Grades
This cutoff grade analysis indicates that a significant portion of the Resources are available for mining at higher cutoff grades, which suggests resiliency with respect to gold price risk.
The resource estimate was prepared by Jonathan Brown., M.B.A., C.P.G., a qualified person. The reserve estimate was prepared by Tom Buchholz, B.S. Eng - MMSA QPM, a qualified person. The estimates are effective as of February 2, 2010. Details of the key assumptions, parameters, and methods used to estimate the mineral reserves and resources, and information regarding the extent to which the mineral resources and reserves may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing or other relevant issues is contained in a technical report entitled "NI 43-101 Technical Feasibility Report Copperstone Project, La Paz County, Arizona" effective February 2, 2010 and revised January 10, 2011, prepared for American Bonanza Gold Corp. by Dr. Corby Anders, Allihies Inc., MMSA QP, C. Eng FlChemE, Tom Buchholz, BS Eng. MMSA, Chris Pratt, LPG and Jonathan Brown, M.B.A., C.P.G.. To review this report in its entirety, follow this link. Mineral resources that are not mineral reserves to not have demonstrated economic viabililty.
DATA QUALITY ASSURANCE AND QUALITY CONTROL
As previously disclosed, the drill samples at Copperstone were collected by Bonanza personnel at the drill for each drill hole. All of Bonanza's facilities are secure, inside the fenced compound. The core was transported to Bonanza's core processing facility on site at Copperstone by Bonanza personnel.
All core was logged for recovery and other geotechnical features, prior to being sawed lengthwise in half by Bonanza personnel. Individual core samples were selected on a geological basis to characterize the gold mineralization associated with various rock types, alteration types and structural horizons. Subsequent to sawing and sampling, the remaining half core was geologically logged and stored on site as reference samples. The samples were bagged, labeled and tied at the Copperstone project site by Bonanza personnel. Geologic information was recorded on standardized sample description forms which included color, rock type, alteration, mineral species and abundance. Samples are stored in a secure facility at the Copperstone project site.
DATS Trucking, Inc. collected samples from the secure facility at Copperstone and transported the samples to representatives of American Assay Laboratories (AAL) in Sparks, Nevada. There, representatives of American Assay Laboratories (AAL) in Sparks, Nevada received the samples and took custody of the samples. AAL is ISO / IEC 17025 certified and has successfully completed Canadian proficiency testing (CCRMP).
At the AAL laboratory, the core samples were dried, crushed to -10 mesh, pulverized to -150 mesh, split to 1,000 gram pulps, and fire assayed for gold two times using 2-assay ton fire assay charges with a gravimetric finish. Reported gold grades are the average of these two assays for each sample. Samples were routinely assayed in duplicate. There is good correlation between the duplicate assays, and Bonanza's QA/QC program and database integrity have been reviewed by several previous independent studieds, and as part of the current Feasibility Study, where it has been judged appropriate for the uses herein. All samples greater than 0.100 opt, standards, and blanks were routinely submitted to additional labs for verification. Standards were routinely inserted for assay. Check assays were routinely submitted to BSI-Inspectorate, Sparks, NV for an additional 5-assay ton gold analysis. BSI-Inspectorate is ISO 9002 certified. Bonanza personnel delivered the samples to the check lab.
CAUTIONARY NOTE REGARDING RESOURCE AND RESERVE ESTIMATES
The Resource and Reserve estimates included in this website are estimates and no assurances can be given that the indicated level of gold production will be achieved. Such estimates are expressions of judgment based on knowledge, mining experience, analysis of drilling and sampling results and industry practices. Valid estimates made at any given time may significantly change when new information becomes available, and reserve estimates established at any given time may, as a result of macro-economic or other factors, cease to be valid in the future. While the Company believes that the resource and reserve estimates included in this website are accurate, by their nature resource and reserve estimates are imprecise and depend to a certain extent upon statistical inferences which may ultimately prove unreliable. If such estimates are inaccurate or are reduced in the future, this could have a material adverse impact on the Company, and adversely affect the results of the Study. Investors are cautioned not to assume that any part or all of the mineral deposit will ever be extracted or processed at a profit.
US Investors are cautioned that the reserve estimates disclosed in this website have been calculated pursuant to Canadian standards, and may not be considered "reserves" by the U.S. Securities and Exchange Commission.
CAUTIONARY NOTE CONCERNING ESTIMATES OF MEASURED, INDICATED AND INFERRED MINERAL RESOURCES
This website uses the terms "Measured and Indicated Mineral Resources". Bonanza advises US investors that while those terms are recognized and required by Canadian regulators, the U.S. Securities and Exchange Commission does not recognize them. Investors are cautioned not to assume that any part or all of mineral deposits in these categories will ever be converted into reserves.
This website also uses the term "Inferred Mineral Resources". Bonanza advises US investors that while this term is recognized and required by Canadian regulators, the U.S. Securities and Exchange Commission does not recognize it. "Inferred Mineral Resources" have a great deal of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. It cannot be assumed that all or any part of an Inferred Mineral Resource will ever be upgraded to a higher category. Under Canadian rules, estimates of Inferred Mineral Resources may not form the basis of feasibility or pre-feasibility studies, except in rare cases. Investors are cautioned not to assume that part or all of an Inferred Resource exists, or is economically or legally mineable.
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