Ligand-Based Partial Extraction Of Soil Samples: An Innovative Approach To The Assessment Of Hydrocarbon Prospectivity

Transcription

1 Ligand-Based Partial Extraction Of Soil Samples: An Innovative Approach To The Assessment Of Hydrocarbon Prospectivity Mark Fedikow Ph.D. P.Eng. P.Geo. C.P.G. Mount Morgan Resources Ltd. Winnipeg, Manitoba CANADA

2 GOAL: CROSS FERTILIZATION MOBILE METAL IONS soil geochemistry ( MMI ) is currently in use by 300 base and precious metal, diamond and industrial mineral explorationists worldwide Commercial and technical successes well documented ( Supplement MMI with an add-on suite of elements and compounds useful in the definition of hydrocarbon geochemical signatures Apply this technology to the search for hydrocarbons based on analogies from the hardrock mining exploration industry

3 What Is Mobile Metal Ions ( MMI ) Technology Part 1: Partial extraction that removes recently arrived ions (sourced from buried/blind metal accumulations) from the surface of soil particles and keeps these ions in solution with a suite of ligands to maintain ions in solution subsequent to extraction Part 2: Soils collected from a specified depth in the soil profile-not from a particular soil horizon

4 MMI THEORY Ions move source to surface in a vertical column and become fixed at an optimum depth in near surface soils Source: hydrocarbon accumulation (metal source) Mobilization by convection (oxidation of hydrocarbons/exothermic), capillary rise, electrochemical, vapour phase. Pathways: post-depositional faults/joints, induced permeability or primary permeability/porosity

5 VERTICAL MIGRATION ANALOGY Vertical ascension of metals from a buried/blind source region (metals/hydrocarbons)

6 SAMPLE COLLECTION Soil samples collected from within 40 cm (16 inches) of surface with a shovel and vinyl scoop CRITICAL: Exact sampling depth determined by an orientation survey Can be collected in disturbed terrain grams required for analysis No field or laboratory preparation sites per day dependant upon terrain conditions

7 Sample Based On DEPTH Not Horizon

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9 BASIC TOOLS FOR MMI SAMPLE COLLECTION

10 HAND AUGER SAMPLING

11 POWER AUGER SOIL SAMPLING

12 Applicable In Cultivated (Disrupted) Fields

13 Applicable To Eluviated and Illuviated Soils

14 Applicable In Complex or Simple Soil Profiles

15 Applicable To Peat Soils

16 Applicable To Sub-Aqueous Environments (W.Australia Salt Lakes/Glacial Lake Sediments)

17 SAMPLE ANALYSIS Part 1: Partial extraction of 50 g soil with 50 ml proprietary extractant (commercially available Mobile Metal Ions Technology: SGS Toronto; ALS-Chemex Perth, W.A.) for 45 elements Part 2: Multi-element/compound add-on ICP-MS/ICP-OES to parts per billion and sub-ppb

18 ANALYTICAL COSTS $45.00 Cdn/sample (exclusive of field collection) for exploration phase surveys

19 INTERPRETATION Multiple approaches import into any GIS platform for contouring/uni- or multi-variate graphics/statistics/3-d Integrate with geophysics/geology

20 DATA MANIPULATION Data presented as Hydrocarbon Discovery Indices ( HDI ) for individual elements and combinations of elements or as nontransformed analyses HDI normalized against known targets and then used to screen larger exploration survey data

21 Data Display

22 MMI ANOMALY CHARACTERISTICS Apical-directly over source region High-background:anomaly contrast Strongly correlate to shape and magnitude of source region Reproducible over time (field and laboratory) Multi-element or single element responses

23 MMI ANOMALY MORPHOLOGY

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25 ANOMALY FORMATION How do the anomalies form and what is the evidence to substantiate that these anomalies are representative of underlying (buried and/or blind) source regions and associated geology?

26 Evidence for vertical migration High resolution geochemical techniques provide geochemical signals over ore deposits Some of these are over demonstrably transported overburden (eg glacial terrain, Canada, salt lakes, Australia) These anomalies are sharp, and vertically above mineralization

27 HARD DATA Pb isotope evidence OMET study of 2003 at Cross Lake Weak leach used to extract Pb from soil samples at the MMI horizon Pb isotopic signature directly over the deposit is similar to mineralization Samples on flanks, at depth, and on the surface have a different isotopic signature!

28 Exothermic:Zn Sulphide to Zn Sulphate Cross Lake Line 40 temperature profiles (Hamilton et al 2002)

29 CONVECTION EXPERIMENT Experiment set-up. A rheostat attached to a light bulb is adjusted to provide a 1 degree centigrade temperature differential, in a water saturated sand column. The water in the lower part of the sand-filled box has been impregnated with blue dye. The bottom part of the box was photographed every day for a week.

30 Convection Day 1 T=1 day. The interface of the blue dye and water is undisturbed.

31 Convection Day 2 T=2 days. A disturbance of the blue dye interface develops around the heated zone.

32 Convection Day 5 T=5 days. A vertical plume of dye ascends directly above the heat zone.

33 Convection Day 7 T=7 days. The chimney above the heat source has reached the water surface.

34 Capillary Rise: 6 Weeks Imprint of blue dye Som e six w eeks after the experim ent ceased (ie light (heat) w as turned off), an imprint of dye just below the surface was noted. This has occurred by capillary rise from the w ater, and evaporation near the sand surface.

35 Capillary Rise

36 Capillary Rise Remember this!! It tells you where you need to sample MMI i.e. The TOP of the soil profile

37 ELEMENT MOBILITY Upward movement of Base Metals Coarse silica sand profile Coarse silica sand profile with 10g carbonate layer

38 Application To The Hydrocarbon Exploration Industry? c.f. Schumacher, 1996

39 CONCLUSIONS MMI Technology is a robust, rapid and cost-effective method of defining apical geochemical anomalies produced by accumulations of metals/hydrocarbons in the subsurface The Technology can discriminate between productive and nonproductive geophysical targets such as 3-D seismic anomalies and thereby focus exploration In regional hydrocarbon prospectivity assessments the Technology can be used to reduce large survey areas to much smaller areas of more significant potential that can be assessed with a combination of detailed soil geochemical surveys and seismic surveys Cost-effective (c.f. 3-D seismic, drilling, other geochemical methods) Innovation/cross fertilization presents opportunities for enhanced hydrocarbon exploration and discovery

40 Mark Fedikow Mount Morgan Resources Ltd. 967 Windermere Avenue Winnipeg, Manitoba, CANADA TEL: /cell: LINK: