======== GENERAL ======== -------------------------------------------------------------- Project: Heli EM Survey Client: Jervois Mining NL and MRT Client Rep: Anthony Jannink Survey By: GEO Instruments GEO Number 2113 infill Area A Survey date: November 2001, April 2002 Survey Base: Sheffield Survey Area: A1 infill: Lake Barrington Area --------------------------------------------------------------- ================= DATA ACQUISITION ================= AIRBORNE SURVEY SPECIFICATIONS Survey flown: November 2001 Traverse line spacing: 200 metres / 100 meters infill Traverse line direction: 000 / 180 degrees Tie line spacing: 2000 metres / 1000 meters infill approx Tie line direction: 090 / 270 degrees approx Survey height: EM towed Bird at 30m agl Electromagnetic System Hummingbird 5 frequency EM system. Data acquisition: Geo Instruments Model G2002 system Geotech Hummingbird system Aircraft: Squirrel helicopter MAGNETOMETER Type: Geometrics G822A Caesium vapour Resolution: 0.001 nT Recording interval: 0.1 sec (approx. 3.5 metres sampling) Installation: Magnetometer sensor mounted in HEM bird. NAVIGATION Flight path navigation: Real time satellite Differential GPS system Navigation equipment: Fugro OMNISTAR GPS receivers Flight path record: WGS84 Easting/ Northing coordinates Radar altimeter: Collins Alt50 GPS base station locations: Fugro OMNISTAR(Real Time DGPS) HUMMINGBIRD COIL SPECIFICATIONS: Bird 1 Before Julian day 67,2002, Flight 93 Channel : 1 2 3 4 5 -------------------------------------------------------------- Freq (Hz) : 7000 6600 980 880 34000 Orientation : CX CP CX CP CP Coil Separation (m) : 6.26 6.26 6.01 6.01 4.93 Bird 2 After Julian day 67, 2002 , Flight 94 Channel : 1 2 3 4 5 -------------------------------------------------------------- Freq (Hz) : 7000 6600 980 880 34000 Orientation : CX CP CX CP CP Coil Separation (m) : 6.25 6.25 6.03 6.03 4.79 NOTE: Processed data from Bird 2 has been adjusted to merge with Bird 1 data. Coil Separation from Bird 1 has been used for resistivity calculations. =============== DATA PROCESSING =============== MAGNETIC DATA The magnetic data has been corrected for regional gradient by subtraction of IGRF model 2001.9 and secular variation model 1995-2000. Diurnal variations have been removed. System parallax has been removed. Tieline levelling has been applied. Microlevelling has been applied. The mean diurnal value and the IGRF base value have been added to the data. ELECTROMAGNETIC DATA The electromagnetic data has been filtered to remove the effects of sferics and other noise sources. Data has been corrected for system drift by subtraction of background zero levels determined from high altitude callibration data. System parallax has been removed. Apparent resistivities and depths have been calculated using both the Nomogram and Inversion techniques using the Geosoft HEM module. Inphase and quadrature channels have been levelled to remove residual flight line features in apparent resistivities. Microlevelling has been applied. GRIDDING - Electromagnetics- Inphase & quad Algorithm: Minimum Curvature Grid mesh size: 20 x 20 metres Grid filter: None GRIDDING - Electromagnetics- Resistivities Algorithm: Minimum Curvature Grid mesh size: 20 x 20 metres Grid filter: none GRIDDING - Magnetics: Algorithm: Minimum Curvature Grid mesh size: 20 x 20 metres Grid filter: None GRIDDING - Digital Terrain: Algorithm: Minimum Curvature Grid mesh size: 20 x 20 metres Grid filter: 3x3 mean LINE NUMBERING Line numbers are in the form 'TLLLAA' where T = Line type (1 = traverse, 7 = tie) LLL = Line sequence number AA = Line attempt number eg: 100201 is traverse line 2 attempt 1 704802 is tie lie 48 attempt 2 BIBLIOGRAPHIC REFERENCE Surveyed by: GeoInstruments Pty Ltd Geo Instruments job number: 2113 Processed by: GeoInstruments Pty Ltd Grid production by: GeoInstruments Pty Ltd ========================== PROCESSED LOCATED DATA : ========================== Format: Geosoft GDB Database Files: Ax_IL_DB.GDB ========================================================================= LOCATED DATA FORMAT ========================================================================= ------------------------------------------------------------------------- Field Field Name Description ------------------------------------------------------------------------- Column 1 LineNo_TLLLAA line number (TLLLAA) Column 2 FlightNo flight Column 3 Julian_Day julian_day (YYYYDDD) Column 4 Fid_geo fiducial- Geoinstruments acqusition system Column 5 Fid_humm fiducial- HEM acqusition system Column 6 Time_hh time (decimal hours) Column 7 AGD66TMAMG55_East AGD66 easting (metres, TMAMG Zone 55) Column 8 AGD66TMAMG55_North AGD66 northing (metres, TMAMG Zone 55) Column 9 GDA94MGA55_East GDA94 easting (metres, MGA Zone 55) Column 10 GDA94MGA55_North GDA94 northing (metres, MGA Zone 55) Column 11 AGD66GEODETIC_LAT AGD66 longitude (decimal degrees, GEODETIC) Column 12 AGD66GEODETIC_LONG AGD66 latitude (decimal degrees, GEODETIC) Column 13 GDA94GEODETIC_LAT GDA94 longitude (decimal degrees, GEODETIC) Column 14 GDA94GEODETIC_LONG GDA94 latitude (decimal degrees, GEODETIC) Column 15 Mag_Raw Raw uncompensated magnetics (nanoTeslas) Column 16 GPSalt_Raw Raw GPS height (metres) Column 17 Radalt_Raw Raw radar altimeter (metres) Column 18 Diurnal Diurnal magnetics (nanoTeslas) Column 19 IGRF IGRF magnetics (nanoTeslas) Column 20 TMI_Corrected Diurnal & IGRF corrected magnetics (nanoTeslas) Column 21 TMI_Levelled Levelled magnetics (nanoTeslas) Column 22 TMI_Final Final magnetics microlevelled (nanoTeslas) Column 23 GPSalt_Final Final GPS height (metres, AHD) Column 24 Radalt_Final Final Radar altimeter (metres) Column 25 DTM_Final Final digital terrain model (metres, AHD) Column 26 cx7Ki_PPM Raw cx7Ki (ppm) Column 27 cx7Kq_PPM Raw cx7Kq (ppm) Column 28 cp6Ki_PPM Raw cp6Ki (ppm) Column 29 cp6Kq_PPM Raw cp6Kq (ppm) Column 30 cx980i_PPM Raw cx980i (ppm) Column 31 cx980q_PPM Raw cx980q (ppm) Column 32 cp880i_PPM Raw cp880i (ppm) Column 33 cp880q_PPM Raw cp880q (ppm) Column 34 cp34ki_PPM Raw cp34ki (ppm) Column 35 cp34kq_PPM Raw cp34kq (ppm) Column 36 cx7Ki_F_L Filtered & Levelled cx7Ki (ppm) Column 37 cx7Kq_F_L Filtered & Levelled cx7Kq (ppm) Column 38 cp6Ki_F_L Filtered & Levelled cp6Ki (ppm) Column 39 cp6Kq_F_L Filtered & Levelled cp6Kq (ppm) Column 40 cx980i_F_L Filtered & Levelled cx980i (ppm) Column 41 cx980q_F_L Filtered & Levelled cx980q (ppm) Column 42 cp880i_F_L Filtered & Levelled cp880i (ppm) Column 43 cp880q_F_L Filtered & Levelled cp880q (ppm) Column 44 cp34ki_F_L Filtered & Levelled cp34ki (ppm) Column 45 cp34kq_F_L Filtered & Levelled cp34kq (ppm) Column 46 cx7Ki_F_LD Final Levelled cx7Ki (ppm) Column 47 cx7Kq_F_LD Final Levelled cx7Kq (ppm) Column 48 cp6Ki_F_LD Final Levelled cp6Ki (ppm) Column 49 cp6Kq_F_LD Final Levelled cp6Kq (ppm) Column 50 cx980i_F_LD Final Levelled cx980i (ppm) Column 51 cx980q_F_LD Final Levelled cx980q (ppm) Column 52 cp880i_F_LD Final Levelled cp880i (ppm) Column 53 cp880q_F_LD Final Levelled cp880q (ppm) Column 54 cp34ki_F_LD Final Levelled cp34ki (ppm) Column 55 cp34kq_F_LD Final Levelled cp34kq (ppm) Column 56 cp34k_AResistINV Apparent cp34k Resistivity (ohms/m) INVERSION technique. Column 57 cp6k_AResistINV Apparent cp6k Resistivity (ohms/m) INVERSION technique. Column 58 cp880_AResistINV Apparent cp880 Resistivity (ohms/m) INVERSION technique. Column 59 cx7K_AResistINV Apparent cx7K Resistivity (ohms/m) INVERSION technique. Column 60 cx980_AResistINV Apparent cx980 Resistivity (ohms/m) INVERSION technique. Column 61 cp34k_ACondINV Apparent cp34k Conductivity (uS/m) INVERSION technique. Column 62 cp6k_ACondINV Apparent cp6k Conductivity (uS/m) INVERSION technique. Column 63 cp880_ACondINV Apparent cp880 Conductivity (uS/m) INVERSION technique. Column 64 cx7k_ACondINV Apparent cx7K Conductivity (uS/m) INVERSION technique. Column 65 cx980_ACondINV Apparent cx980 Conductivity (uS/m) INVERSION technique. EM DATA: ========= Nomenclature for field name / processing relationship: '_ppm' Filtered Raw data: '_F_L' Filtered and levelled data. ( FOR CDI Production ) '_F_LD' Filtered, levelled and microlevelled data. '_AResistINV' Apparent Resistivity ohms/m calculated using the INVERSION technique. '_ACondINV' Apparent Conductivity uS/m calculated using the INVERSION technique. GRIDDED DATA FILES: =================== Files: Extensions as for processed data above. Format: ER Mapper Cell size: 20 metres Datum: AGD66 Projection: TMAMG Zone: 55