SASKATCHEWAN STRATIGRAPHY GLACIAL EXAMPLE BOULDERS IN GLACIAL DEPOSITS

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1 SASKATCHEWAN STRATIGRAPHY GLACIAL EXAMPLE BOULDERS IN GLACIAL DEPOSITS 51

2 SASKATCHEWAN STRATIGRAPHY GLACIAL SURFICIAL STRATIFIED DEPOSITS 52

3 SASKATCHEWAN STRATIGRAPHY GLACIAL EXAMPLE OF SEDIMENT DEPOSITION HISTORY 10,000 y 20,000 y 100,000 y 175,000 y 600,000 y 2 MA 70 MA TIME 100+ MA Empress Stratified Judith Group River Surficial Sand Lower Upper Lea Bearpaw Battleford Sand Salt Intertill Dundurn Warman Mennon Park Floral Deposits Collapse and Gravel Shale Sand Silt Till 53

4 HYDROSTRATIGRAPHY HYDROSTRATIGRAPHY Surficial Unconfined Aquifers Till Aquitard Intertill Blanket Aquifer Till Aquitard Intertill Channel Aquifer Bedrock Valley Aquifer Bedrock Aquitard 54

5 HYDROSTRATIGRAPHY HYDRAULIC CONDUCTIVITIES Unconsolidated Max Median Min Deposits (m/s) (m/s) (m/s) Gravel 3 x x x 10-4 Sand 6 x x x 10-7 Silt / Loess 2 x x x 10-9 Fractured Till 2 x x x Unfractured Till 2 x x x Lacustrine Clay 5 x x x Marine Clay 2 x x x Overall range is more than 10 orders of magnitude 55

6 SITE CHARACTERIZATION SESSION 3 EXPLORATION PLAN - Determine Spatial Requirements - Determine Base of Exploration - Determine Sampling Requirements - Geophysics - Laboratory Testing - Insitu Testing - Drill Method - Instrumentation - Survey 56

7 SPATIAL REQUIREMENTS DETERMINE SPATIAL REQUIREMENTS Number of boreholes (or test pits) to adequately define the stratigraphy: - Size of project - Complexity of site - Risks associated with construction of a poor site model - Budgetary constraints (which is an unfortunate reality) - Required depth of investigation 57

8 SPATIAL REQUIREMENTS THREE HOLE SPECIAL 58

9 SPATIAL REQUIREMENTS Significantly Larger Exploration Program 59

10 BASE OF EXPLORATION DETERMINE BASE OF EXPLORATION - Should be known ahead of time - Should be structural marker if possible (very deep and rarely used) - In most cases a stratigraphic marker is used (e.g. bedrock surface) and is usually sufficient 60

11 Stratigraphic Interpretation Marker beds - have significant lateral continuity, must be lithologically recognizable and serves as a reference, datum, or base of exploration Structural Markers - Used in interpretation of structure (spatial arrangement of rock k or soil) resulting from deposition, erosion, faulting, etc. - Must be regionally extensive, flat lying, easily recognizable, and not subjected to erosion. - Bentonite beds, Judith River Formation, White Speckled Shale Stratigraphic Markers - Used for interpretation of stratigraphy - Can be erosional surfaces - Bedrock surface is best, or contact between Sutherland Group and Saskatoon Group 61

12 SURFICIAL STRATIFIED DEPOSITS Stratigraphic Marker SASKATOON GROUP Stratigraphic Marker SUTHERLAND GROUP Stratigraphic Marker BEARPAW FORMATION JUDITH RIVER FORMATION Structural Marker LEA PARK FORMATION 62

13 SAMPLING REQUIREMENTS DETERMINE SAMPLING REQUIREMENTS - Disturbed samples (cuttings samples) - grainsize - moisture content - lithology for stratigraphic interpretation - etc. - Undisturbed samples (core, shelby tube, etc) - preconsolidation pressures - direct shear - permeability - etc. 63

14 SAMPLING REQUIREMENTS Disturbed Cuttings Collected using sieves, washed and dried on low heat 64

15 SAMPLING REQUIREMENTS Disturbed Cuttings 65

16 SAMPLING REQUIREMENTS Disturbed Cuttings From Auger 66

17 SAMPLING REQUIREMENTS Undisturbed Core 67

18 SAMPLING REQUIREMENTS Undisturbed Core 68

19 SAMPLING REQUIREMENTS Zone from which water sample was acquired of water sample Undisturbed Core 69

20 SAMPLING REQUIREMENTS Undisturbed Shelby Tube 70

21 GEOPHYSICS Surface geophysics Borehole geophysics 71

22 GEOPHYSICS SURFACE GEOPHYSICS Speed / portability Non intrusive/destructive Near continuous information Relatively simple operation Single or dual person operation 72

23 GEOPHYSICS SURFACE GEOPHYSICS Interference overhead lines, buried lines, any conductors or power sources may mask features of interest Parameter measure of electrical conductivity, NOT of contaminant concentration, geologic material type, fracture spacing, etc. Indirect Measure known benchmarks are required, e.g. outcrops, boreholes, water samples, etc. Need boreholes/piezometers to ground truth data 73

24 GEOPHYSICS SURFACE GEOPHYSICS Factors influencing electrical conductivity: Degree of saturation Degree of compaction Salinity of pore water Soil composition (clay content) 74

25 GEOPHYSICS COMMON SURFACE GEOPHYSICAL METHODS EM 38 EM 31 EM 34 GEM/2 ERT (Electric Resistivity Tomography) 75

26 GEOPHYSICS COMMON SURFACE GEOPHYSICAL METHODS EM 38 For shallow use (about 1.5 m) One person operated Held at approximately ground level 76

27 GEOPHYSICS COMMON SURFACE GEOPHYSICAL METHODS EM 31 Most commonly used Consists of a transmitter coil and a receiver coil with a control unit in the middle 77

28 GEOPHYSICS COMMON SURFACE GEOPHYSICAL METHODS EM 31 Pipeline Location 78

29 GEOPHYSICS COMMON SURFACE GEOPHYSICAL METHODS EM 34 Same principle used as EM31 2-operator system, slower Typically used for mapping groundwater contaminant plumes and for groundwater exploration Measurement depth up to 60 m good to around 20 m 79

30 GEOPHYSICS COMMAN SURFACE GEOPHYSICAL METHODS EM 34 Receiver Transmitter Datalogger 80

EM34 Survey E 446,000 E 446,000 E 447,000 E 447,000 E 448,000 E 448,000 81 N 5,751,000 N 5,752,000 N 5,753,000 N 5,754,000 N

31 EM34 Survey E 446,000 E 446,000 E 447,000 E 447,000 E 448,000 E 448, N 5,751,000 N 5,752,000 N 5,753,000 N 5,754,000 N 5,755,000 N 5,751,000 N 5,752,000 N5,753,000 N 5,754,000 N5,755,000 GEOPHYSICS CONDUCTIVITY ms/m

32 GEOPHYSICS COMMON SURFACE GEOPHYSICAL METHODS Electric Resistivity Tomography (ERT) Environmental monitoring and site characterization Detection of groundwater flow and contaminant paths Groundwater exploration Stratigraphic mapping (particularly bedrock topography) 82

33 GEOPHYSICS COMMON SURFACE GEOPHYSICAL METHODS Electric Resistivity Tomography (ERT) 83

34 Electric Resistivity Tomography (ERT) 54 km of ERT line Mapping channel aquifer at industrial site 84

35 GEOPHYSICS Electric Resistivity Tomography (ERT) 420 m Resistivity Slice Industrial Site 85

36 GEOPHYSICS Electric Resistivity Tomography (ERT) 440 m Resistivity Slice Industrial Site 86

37 GEOPHYSICS Electric Resistivity Tomography (ERT) 460 m Resistivity Slice Industrial Site 87

38 GEOPHYSICS Location of Aquifer Electric Resistivity Tomography (ERT) 480 m Resistivity Slice Industrial Site 88

39 Electric Resistivity Tomography (ERT) Able to determine depth to bedrock Great for targeting drill holes Expensive 89

40 GEOPHYSICS BOREHOLE GEOPHYSICS Non biased stratigraphic information Ideal for optimizing placement of instrumentation Help stratigraphic interpretations Provide a continuous record of borehole Certain methods can be completed through installations after hole is drilled 90

41 GEOPHYSICS BOREHOLE GEOPHYSICS Natural Gamma Single Point Resistance Self Potential Caliper Density EM-39 Most Common All sorts of more exotic logging devices for virtually any application 91

42 GEOPHYSICS BOREHOLE GEOPHYSICS EM 39 - Borehole Geophysics 92

43 GEOPHYSICS BOREHOLE GEOPHYSICS NG, SPR, SP 93

44 GEOPHYSICS BOREHOLE GEOPHYSICS NG, SPR, SP 94

45 95

46 LABORATORY TESTING LABORATORY TESTING Used to define material properties in site model There are tests to measure any soil or water property Common laboratory tests used in site characterization include: - Atterberg Limits - Carbonate Content - Compressibility (Preconsolidation( Pressures) - Direct Shear - Triaxial Permeability - Groundwater Chemistry 96

47 LABORATORY TESTING LABORATORY TESTING ATTERBERG LIMITS Are a composite index of clay mineralogy and grainsize distribution in terms of workability of soil under field conditions Provide expected behavior of soils over a range of water contents Most common soil test in the world Can be completed on disturbed samples 97

48 LABORATORY TESTING ATTERBERG LIMITS BRITTLE PLASTIC LIQUID X SHEAR STRESS SHEAR STRESS SHEAR STRESS STRAIN STRAIN STRAIN WATER CONTENT W P I P W L Optimum Water Content For Compaction W P = PLASTIC LIMIT W L = LIQUID LIMIT = SOIL BECOMES LIQUID = NO SHEAR STRENGTH I P = PLASTICITY INDEX THE MORE CLAY THE HIGHER THE NUMBER 98

49 LABORATORY TESTING ATTERBERG LIMITS BRITTLE PLASTIC LIQUID X SHEAR STRESS SHEAR STRESS SHEAR STRESS STRAIN STRAIN STRAIN W n W P W L VERY HARD HARD FIRM SOFT W n = NATURAL WATER CONTENT VERY SOFT LIQUID LIQUIDITY INDEX = W n -W p W n -W L LI = 0 firm near optimum water content = 0.9 is almost a liquid 99

50 LABORATORY TESTING CONSOLIDATION TESTS Determine how a soil will behave to the application of a load Allow prediction of settlement Enable the determination of preconsolidation pressures which can be used to help separate tills Require undisturbed samples 100

ENCE 3610 Soil Mechanics. Site Exploration and Characterisation Field Exploration Methods

ENCE 3610 Soil Mechanics. Site Exploration and Characterisation Field Exploration Methods ENCE 3610 Soil Mechanics Site Exploration and Characterisation Field Exploration Methods Geotechnical Involvement in Project Phases Planning Design Alternatives Preparation of Detailed Plans Final Design