Circular No. 03/2011/TT-BTNMT on the content of detailed geological and mineral resource maps and design, layout of various types of mineral assessment work

CIRCULAR

Regulations on the content of detailed geological and mineral maps and design,

arrangement of types of mineral assessment work

MINISTER OF NATURAL RESOURCES AND ENVIRONMENT

Pursuant to the Minerals Law and the Law amending and supplementing certain articles of the Minerals Law;

Pursuant to Decree No. 25/2008/NĐ-CP dated March 4, 2008 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Natural Resources and Environment, and Decree No. 89/2010/NĐ-CP dated August 16, 2010 of the Government amending and supplementing Article 3 of Decree No. 25/2008/NĐ-CP;

Considering the proposal of the Director of the Vietnam Geological and Mineral Resources Administration and the Head of the Legal Department,

REGULATIONS

Chapter 1

GENERAL PROVISIONS

Article 1. Scope of Regulation

This Circular stipulates the work of mineral assessment at scales of 1:10,000, 1:5,000, and 1:2,000 (hereinafter referred to as mineral assessment).

The contents of the items of work regulated include: preparation of detailed geological and mineral maps; design and adjustment of types of work for assessing mineral potential, arrangement of mineral assessment works, estimation and prediction of mineral resources.

Article 2. Applicability

This Circular applies to state management agencies, organizations implementing investigation and assessment tasks of minerals, and other relevant organizations and individuals.

Article 3. Objectives, tasks, and products of mineral assessment work at scales of 1:10,000, 1:5,000, and 1:2,000

1. The objective of mineral assessment is to discover and assess mineral potential, determine the distribution pattern of minerals, estimate and predict mineral resources, delineate areas with mineral potential for further exploration and exploitation.

2. Tasks of geological work in mineral assessment:

a) Measuring, drawing, and delineating sedimentary, igneous, and metamorphic formations according to lithological composition; detecting and measuring folds and faults;

b) Detecting, measuring, and delineating areas of distribution of thermally altered rocks, metasomatic rocks, talus, and mineral outcrops, ore bodies;

c) Designing technical works aimed at discovering and assessing mineral potential;

d) Arranging geochemical sampling lines, geophysical measurements, heavy mineral sampling, drilling and trenching works; processing topographic, geochemical, mineralogical, geophysical, drilling, and trenching data and analyzing samples;

đ) Estimating and predicting resources for ore bodies;

e) Determining the distribution pattern of minerals and delineating areas with prospects for further exploration.

3. Products of mineral assessment include: original geological and mineral data; geological and mineral maps; detailed ore body maps (diagrams); cross-sections, planar diagrams for resource estimation, and other specific designed documents according to the project; reports on the results of mineral assessment.

Article 4. Classification of assessment areas based on complexity level

The complexity level of mineral assessment areas depends on the complexity level of geological structures and the complexity level of mineral objects, divided into four groups: simple, moderate, complex, very complex.

Classification of mineral assessment areas based on complexity level is specified in Appendix 1 issued together with this Circular.

Article 5. Scale of geological and mineral maps in mineral assessment

The scale of geological and mineral maps in mineral assessment depends on the complexity level of geological structures, investigation steps, and the complexity level of mineral objects determined specifically in the project.

Guidelines for the scale of geological and mineral maps to be established in mineral assessment are specified in Appendix 2 issued together with this Circular.

Article 6. Inspection and Acceptance

The work of inspecting various types of tasks during the implementation of mineral assessment according to current regulations; the acceptance work shall be carried out in accordance with Circular No. 11/2009/TT-BTNMT dated August 11, 2009, issued by the Ministry of Natural Resources and Environment, which stipulates the acceptance of construction results and the review of projects and reports in the field of geology and minerals.

Chapter 2

CONTENT OF CREATING GEOLOGICAL MINERAL MAPS

Article 7. Tasks for Creating Geological Mineral Maps

1. The geological route aims to survey, delineate, and detail geological formations on the map; detect, survey folded structures, fractured zones, breccias, and faults; determine the relationship between folded structures, faults, and geological formations and mineral expressions; detect and delineate mineral precursors and signs; analyze and utilize drilling and mining data to clarify the boundaries and scale of ore-bearing objects or those potentially containing ores; monitor and control the development of ore-bearing objects along strike and dip directions as required, as shown in the project proposal.

2. Create topographic maps and weathered crust maps for areas with potential sand deposits or exogenous origin mines.

3. Determine harmful and beneficial destructive factors; identify favorable factors for ore accumulation and factors that destroy and transport ores.

4. Examine the nature of geochemical halos, mineral particles, and anomalous geophysical features that may relate to minerals to discover minerals.

5. Establish maps, cross-sections, and other types of documents, fully depicting the distribution of geological formations, folded structures, fractured zones, breccias, faults, and geological factors that are precursors and signs of mineral discovery; the relationships between geological formations and their ore-forming processes in space and over time.

6. Process and link various types of geophysical, geochemical materials, heavy mineral samples, mining and drilling results, remote sensing image analysis, and geological sample analysis to create geological mineral maps.

Article 8. Survey Density in Creating Geological Mineral Maps

The level of detail of the route for creating geological mineral maps is calculated based on the length of the route and the number of observation points within an area of 1 km².²The requirement for the level of detail in creating geological mineral maps depends on the scale of mapping, the complexity of the geological and mineral objects designed specifically in the project proposal. The guidelines for the level of detail in mapping geological mineral maps are specified in Appendix 3 attached to this Circular.

Article 9. Content of Mapping Sedimentary Formations in Creating Geological Mineral Maps

1. Survey, classify, and fully represent sedimentary sets and layers according to lithological components; determine their position, composition, thickness, structure, and rock formation; detect and represent changes in sedimentary sets and layers along strike and dip directions; determine the relationship between sedimentary sets and layers and igneous and metamorphic formations; determine the mineralogical and chemical composition of typical sedimentary sets and layers; detect and delineate sedimentary sets and layers with compositions, colors, structures, and formations that can be used as marker beds.

2. Create topographic maps for areas containing sand deposits and weathered crust maps for areas containing weathered-origin mineral deposits; determine the relationship between minerals and topographic and weathered crust factors.

3. Detect and delineate folded structures and faults; survey and determine changes in the composition, structure, and thickness of geological formations in the anticline domes and fault zones.

4. Identify sedimentary sets and layers that are minerals, contain minerals, or play a role as favorable environments for mineral accumulation.

5. Detect and collect animal, plant, spore, and pollen fossils.

6. Determine the relationship between geological formations and topographic and geomorphological factors.

7. Determine and delineate thermally altered and metasomatically altered formations in sedimentary sets and layers, on anticline domes, and at locations where sedimentary thickness or composition changes abruptly.

Article 10. Content of mapping volcanic rock formations in the mineral geological map

1. Mapping and detailed division of volcanic rock formations according to petrographic components, morphology; determining and representing the spatial position, changes in composition, structure, and texture of volcanic rocks; identifying and delineating sedimentary layers and volcanic sediment lenses within volcanic rocks.

2. Determining the relationship between volcanic rocks and sedimentary rocks, intrusive rocks, and metamorphic rocks; identifying changes in composition, structure, and texture of volcanic rocks with respect to subvolcanic intrusions; identifying and delineating volcanic vent rocks to construct a volcanic structural model.

3. Determining the mineralogical, chemical, structural, and textural characteristics of volcanic rocks.

4. Identifying and delineating thermally altered rocks and ore-bearing indicators within volcanic rocks.

Article 11. Content of mapping intrusive formations in the mineral geological map

1. Mapping intrusive bodies; detailed division of intrusive rocks within the body according to petrographic components, structure, and texture; determining and mapping thermal metamorphic zones, metasomatic zones, and hydrothermal alteration zones on boundaries and within intrusive bodies; determining the attitude of contact between intrusive bodies; determining the relationship between intrusive bodies and surrounding rocks.

2. Determining the mineralogical and chemical composition of intrusive rocks; determining their geochemical characteristics.

3. Determining and mapping fault systems within intrusive bodies; identifying and delineating vein rock formations and ore-indicating features within intrusive rocks.

4. Determining the petrographic composition, structure, and texture, mineralogical and chemical composition of intrusive rocks, metamorphic rocks, hydrothermally altered rocks, and vein rocks associated with intrusive bodies.

Article 12. Content of mapping metamorphic rocks in the mineral geological map

1. Delineating and mapping in detail rock associations with different petrographic compositions; identifying and delineating groups and layers marked with preserved primary rock characteristics; mapping and determining the structural cross-sections of metamorphic rocks.

2. Determining the mineralogical, chemical, structural, and textural characteristics of metamorphic rocks.

3. Determining the relationships among metamorphic rocks, rock associations, and their relationships with sedimentary rocks and magmas.

4. Identifying and delineating zones of hydrothermal alteration, metasomatic zones, and ore-indicating features within the distribution area of metamorphic rocks.

Article 13. Content of mapping folding and fault structures in the mineral geological map

1. Determining and delineating folds, high concentration fault zones, cataclastic zones, mylonite zones.

2. Determining and representing the shape of folds on plan and cross-section; determining the attitude of axial planes and limbs of folds, changes in strike and dip of fold axes in space; determining the thickness changes of rock layers on the anticline and limbs; identifying high concentration fault zones on the anticline parts of folds and their relationship with vein rocks, hydrothermally altered rocks, and ore-indicating features.

3. Determining the structural characteristics of faults and the expression of fault zones, high concentration fault zones, cataclastic zones, and mylonite zones along strike and across dip; determining their impact on changes in structure and composition of sedimentary, magmatic, and metamorphic formations. Identifying hydrothermally altered zones and hydrothermal rock formations within high concentration fault zones and cataclastic zones; determining their relationship with ore-indicating features.

Article 14. Content of mapping objects containing ore bodies and mineral veins in geological and mineral resource maps

Detect, map, monitor, and represent all mineral manifestations within the assessment area:

1. Define the distribution areas of sedimentary formations, magmatic rocks, and metamorphic rocks that are minerals; determine their structure, scale, mineralogical composition, chemical composition, structural tectonics, assess quality, and potential for utilization;

2. Define the distribution areas of mineral-bearing boulder fields, hydrothermal altered rocks, and metasomatic rocks directly related to ores; determine their size, density, direction of movement, and evaluate mineral potential;

3. Detect, monitor, and delineate zones of rock alteration surrounding ores, metasomatic rocks, mineralized zones, and ore-hosting structures. Determine the scale, structure of mineralized zones, their orientation, and spatial development; determine the distribution patterns of ore bodies within mineralized zones;

4. For ore bodies, define upper and lower boundaries, orientation, changes in composition, architectural and structural characteristics of ores with depth; monitor and predict changes and development of ore bodies along strike and dip directions; relationship between ore bodies and altered rocks and surrounding rocks; determine mineralogical composition and assess mineral distribution characteristics within ore bodies; determine architectural and structural features; take samples to determine the composition and content of valuable and harmful substances in ores to assess the potential for utilizing minerals; determine physical and mechanical properties of minerals.

Chapter 3

DESIGN AND ARRANGEMENT OF MINERAL ASSESSMENT WORKS

Article 15. Tasks of designing and arranging mineral assessment works

The tasks of designing and arranging mineral assessment works include:

1. Design and adjust technical assessment work designs;

2. Arrange various types of mineral detection and evaluation works;

3. Link, process, update, and supplement content of various types of documents serving design and adjustment of mineral assessment work designs.

Article 16. Content of designing and adjusting technical assessment work designs

The content of designing and adjusting technical assessment work designs includes:

1. Link and process data from various types of geological and mineral mapping, geophysical, geochemical, gravimetric, sample analysis, remote sensing, and previous phase documents;

2. Establish ore body maps, sampling plans, cross-sections to determine and diagnose the development of mineralized zones and ore bodies on surface and subsurface. Detailed drawings for mineral diagnosis must fully reflect the ore body structure, sampling locations, and sample analysis results;

3. Design field sampling lines for geochemistry, gravimetry, detailed geophysics, drilling projects, and excavation works suitable for actual topography, geomorphology, and new geological and mineral information to enhance the effectiveness of detecting and evaluating the scale and quality of ore bodies;

4. Update documents, revise detailed maps, plans, and cross-sections; adjust work designs based on new information.

Article 17. Arrangement of Various Types of Mineral Detection and Evaluation Works

1. Field inspection route to reasonably arrange geochemical, gravimetric, and detailed geophysical sampling lines. Inspection contents include:

a) Detect and determine the position, orientation, width, and length of predicted mineralized zones. Each geochemical, gravimetric, and detailed geophysical sampling area must have at least two inspection routes crossing the entire width of the mineralized zone;

b) Determine suitable terrain positions for geochemical sampling and geophysical measurements; adjust sampling line designs for geochemistry, gravimetry, and geophysics to fit actual topography, geomorphology, and geological and mineral conditions;

c) Arrange geochemical, gravimetric, and geophysical sampling lines.

2. Field inspection contents and arrangement of drilling and excavation works for mineral assessment:

a) Study the proposed location for project placement; determine the geological structure of the mineralized zone at the outcrop (or potentially exposed) ore body or mineral host object along the proposed project line. If no mineralization signs are found along the project line, conduct inspections in both directions with a minimum distance equal to half the mineral assessment grid network;

b) Determine the structure and orientation of the ore body and surrounding rocks;

c) Investigate folding and destruction structures that may cause ore displacement, and estimate (predict) displacement distances;

d) Determine suitable terrain positions for construction; adjust project positions and designs to fit actual conditions;

e) Arrange projects: determine project locations and set project markers.

Article 18. Office Work

Office work has the responsibility to perfect technical documents, prepare annual/step geological reports for inspection and acceptance. The contents of office work include:

1. Supplementing and updating the results of sample analysis into the geological diary, construction drawings;

2. Adjusting rock and ore names to be consistent with the results of sample analysis;

3. Reviewing the results of sample analysis, identifying samples that do not match the geological object, selecting samples for retesting; evaluating the quality of sample analysis; handling batches of samples with analysis results exceeding allowable error margins;

4. Supplementing and revising map materials, cross-sections, detailed plans, mineral geological maps, and other technical documents to be consistent with current information;

5. Preparing reports on the implementation results according to the annual plan;

6. Serving inspection and acceptance.

Chapter 4

PREPARATION OF COMPREHENSIVE REPORTS, CALCULATION OF RESOURCES, AND FORECASTING

Article 19. Tasks of preparing comprehensive reports

The tasks of preparing comprehensive reports include processing and summarizing all types of project documents for mineral resource assessment, establishing a complete and consistent set of drawing and explanatory materials reflecting the actual geological and mineral conditions within the assessed area; calculating mineral resources with appropriate reliability as prescribed; determining the distribution patterns of ore deposits; delineating areas with potential for further exploration.

Article 20. Contents of comprehensive report preparation work

The contents of the comprehensive report on mineral resource evaluation include:

1. Reviewing the results of sample analysis and retesting various types of samples. Collecting and sending samples for analysis and retesting if necessary.

2. Drafting the outline of the comprehensive report;

3. Establishing uniform guidelines for the entire report;

4. Supplementing the results of sample analysis into original documents. Adjusting rock and ore names to be consistent with the results of sample analysis;

5. Creating tables of thickness and average grade based on drilling projects as the basis for establishing, supplementing, and adjusting resource calculation drawings;

6. Establishing and digitizing drilling and excavation design drawings. Accurately marking the location, thickness, and grade of ore bodies in drilling projects. Reviewing and adjusting tables of thickness and average grade based on drilling projects to be consistent with drilling design drawings;

7. Checking topographic, geophysical, geochemical, and gravimetric survey drawings to ensure consistency among different types of documents. Selecting materials and information for use in compiling comprehensive documents;

8. Establishing drawings and appendices meeting the requirements of the report;

9. Establishing drawings, editing smaller versions of drawings, and selecting illustrative images for the explanatory report;

10. Analyzing geological structures, ore zones, and ore bodies, determining and predicting the development potential of ore zones and ore bodies at surface and subsurface levels. Building a mineral formation model. Determining the distribution patterns of mineral resources;

11. Establishing criteria for selecting and delineating areas for further exploration;

12. Establishing the explanatory report;

13. Submitting for acceptance, review, and approval of the report at the competent authority level;

14. Revising the report; submitting for approval.

Article 21. Sample Collection for Geological Museum

Contents of sample collection for the Geological Museum:

1. Statistics of typical rocks, metamorphic rocks, and ores within the mineral resource assessment area;

2. Selecting specimens, cleaning, and beautifying samples;

3. Preparing sample records and lists;

4. Handing over to the Geological Museum.

Chapter 5

CONTENTS AND FORMS OF REPRESENTATION OF SOME KEY DOCUMENTS IN MINERAL RESOURCE ASSESSMENT

Article 22. Main Documents to be Established in Mineral Assessment

The main documents to be established in mineral assessment include:

1. Drawing Documents:

a) Map of actual conditions and layout of works;

b) Geological and mineral map;

c) Geological cross-section of ore body (or resource calculation cross-section);

d) Ore sampling plan;

đ) Resource calculation cross-section (longitudinal section);

e) Engineering drawing for drilling and excavation works;

2. Explanatory Report.

3. Appendices:

a) Statistics of coordinates, height of polygonal network, control points, drilling and excavation works, construction lines;

b) Statistics of analytical results of samples, processing results of check samples;

c) Table of ore body thickness and average grade according to works;

d) Table of ore body thickness and average grade according to resource calculation blocks;

d) Table of resources of ore bodies;

e) Photographs and drawings of ore outcrops, geological structures, topography, geomorphology with evidence of reliability of geological and mineral conclusions.

Article 23. Content and Presentation of Main Drawings

1. Actual Conditions Geological Map: The actual conditions geological map is established on the basis of topographic maps, including the following contents:

a) Geological route, observation points; geochemical sampling lines, heavy mineral lines, geophysical measurement lines; investigation (exploration) lines; drilling and excavation works (including old works collected and utilized); geological formations and their attitudes encountered at observation points along the geological route and at drilling and excavation works; boundaries of geological formations, groups, layers, rock associations, lithofacies, metamorphic zones; locations of ore boulders, metamorphic rocks; marked layers; locations of fault zones, breccia, mylonite, hydrothermal alteration zones;

Locations of drilling and excavation works must be accurate according to geodetic coordinates and heights;

b) Locations of fossilized animal and plant remains, spores, pollen; caves, archaeological sites, mining locations;

c) Boundaries of areas already investigated, explored, mined (if any) within the evaluation area;

2. Geological and Mineral Map:

The geological and mineral map is established on the basis of topographic maps. Contents that must be shown on the geological and mineral map include:

a) Boundaries and distribution areas of geological units, geological formations according to petrographic composition, phase, facies, architecture, structure; folds, faults, metamorphic zones; marked layers; attitudes of geological formations; locations of fossilization;

b) Distribution areas of ore bodies, ore boulder fields, hydrothermal metamorphic zones, metasomatic zones; boundaries of ore zones and other mineralization indicators;

c) Drilling and excavation works: information about work numbers, thickness, quality of minerals at works; drill holes clearly indicate the height of the work opening and depth;

đ) Geochemical dispersion areas, mineral anomalies, related geophysical anomalies;

đ) Area proposed for transfer of exploration;

e) Geological cross-sections: each geological and mineral map must have at least two accompanying cross-sections.

3. Sampling Plan:

The sampling plan is established on the basis of topographic maps at scales of 1:500 to 1:2,000. In cases where there is no suitable topographic map, a topographic map enlarged from a smaller scale map can be used. Contents that need to be shown include:

a) Symbols and numbers of works;

b) Geological formations encountered in works;

c) Symbols and numbers of samples, sample length (according to scale), main beneficial component grades affecting resource calculation criteria; distinguished by levels: less than boundary grade, boundary grade to less than minimum average grade according to resource calculation block, greater than or equal to minimum average grade according to resource calculation block. In cases where harmful components directly affect ore body delineation, harmful component grades also need to be shown;

d) Boundaries of ore bodies, boundaries and symbols of resource calculation blocks;

đ) In cases where there are few ore bodies and sparse works, it is permissible to incorporate the sampling plan into the geological and mineral map using larger-scale extracts placed next to the works or outside the drawing frame;

e) For horizontal ore bodies, samples are taken vertically, establishing a vertical sampling cross-section.

4. Resource Calculation Cross-Sections:

Resource calculation cross-sections are established at the same scale or larger than the sampling plan (or longitudinal projection). Contents that must be shown on the cross-sections include:

a) Topographic cross-section, elevation scale;

b) Location and number of works. For drilling works, the height of the work opening and depth must be clearly indicated; location of encountering ore body boundaries in works, depth of encountering ore pillars and walls; thickness and grade of ore encountered in works; geological formations encountered in works;

c) Boundaries and distribution areas of ore bodies; boundaries and distribution areas of geological formations;

d) Boundaries, symbols, and distribution areas of resource blocks.

5. Resource Calculation Longitudinal Sections:

Resource calculation longitudinal sections are established separately for each ore body; multiple ore body resource calculation sections can be shown on the same drawing when their projected boundaries do not overlap. Contents that need to be shown on the resource calculation sections include:

a) Outcrop boundaries of ore bodies on the surface (outcrop);

b) Works: showing the location of works on the surface and the projection of the location of works cutting through ore pillars; thickness and grade of ore encountered at works;

c) Resource calculation blocks; data on area, thickness, average grade of blocks, quantity of resources in blocks.

Article 24. Content and presentation form of the explanatory report and appendices

The content and presentation form of the explanatory report and appendices shall be carried out in accordance with the regulations on project establishment, basic geological investigation reports on minerals, and the regulations on the establishment, submission, preservation, and utilization of geological reports.

Article 25. Form of mineral evaluation documents

1. All types of drawing documents, appendices, and verbal descriptions in mineral evaluations must be computerized.

2. Standardize symbols and instructions for all types of reporting documents. Symbols and color conventions for geological position names, mineral names; symbols and presentation methods for actual document maps, actual mineral geological maps shall be implemented according to the provisions in Appendix 4 and Appendix 6 of the Regulation on Geological Surveying and Mineral Exploration at a scale of 1:50,000 issued together with Decision No. 13/2008/QĐ-BTNMT dated December 24, 2008 of the Minister of Natural Resources and Environment.

Chapter 6

IMPLEMENTING PROVISIONS

Article 26. Effectiveness and Responsibility for Implementation

1. This Circular takes effect from March 15, 2011.

2. The Director of the Geological and Mineral Resources Department is responsible for guiding, monitoring, and inspecting the implementation of this Circular.

3. During the implementation of this Circular, if difficulties arise, organizations and individuals concerned shall promptly report to the Ministry of Natural Resources and Environment for consideration and resolution./.