ontario prospectors association ground gravity … · ontario prospectors association - 5 -...

395, avenue Centrale, Val-d’Or, Québec Canada J9P 1P4 (819) 874-8800 (819) 874-8801

Consultation et levés géophysiques au sol et en forageSurface & Borehole Geophysical Surveys and Consulting

ONTARIO PROSPECTORS ASSOCIATION

GROUND GRAVITY SURVEY

LAKE NIPIGON REGION GEOSCIENCE INITIATIVE NORTHERN ONTARIO, CANADA

TECHNICAL REPORT

03N718 JULY 2004

ONTARIO PROSPECTORS ASSOCIATION - I - LNRGI/03N718

TABLE OF CONTENTS

1. THE MANDATE .................................................................................................................. 1

2. THE SURVEY AREA ............................................................................................................. 3

3. SURVEY PROGRESS............................................................................................................. 4

4. GPS ACQUISITION ............................................................................................................. 6

5. GRAVITY ACQUISITION........................................................................................................ 9

6. COMPILATION AND DELIVERABLES........................................................................................ 24

7. REFERENCES ................................................................................................................... 27

LIST OF FIGURES

GENERAL LOCATION OF THE SURVEY AREA ..................................................................................... 2

MAP TILE LAYOUT .................................................................................................................... 3

-999 BASE STATION DESCRIPTION ..............................................................................................11






RESIDUAL CUMULATIVE DRIFT – GRAVITY METER B ........................................................................19

RESIDUAL CUMULATIVE DRIFT – GRAVITY METER C ........................................................................20

RESIDUAL CUMULATIVE DRIFT – GRAVITY METER D........................................................................20

APPENDIX A - TABLES

PRODUCTION LOG – GRAVITY METER B.......................................................................................28

PRODUCTION LOG – GRAVITY METER C.......................................................................................31

PRODUCTION LOG – GRAVITY METER D.......................................................................................33

ONTARIO PROSPECTORS ASSOCIATION - 1 - LNRGI/03N718

1. THE MANDATE

PROJECT ID Lake Nipigon Region Geoscience Initiative (LNRGI) Our reference: 03N718

GENERAL LOCATION Lake Nipigon Embayment Area, Ontario, Canada

CUSTOMER Ontario Prospectors Association (OPA) 1000 Alloy Drive, Thunder Bay, Ontario P7B 6A5 Tel.: (866) 259-3727 Fax: (807) 622-4156

REPRESENTATIVES Mr. Wally Rayner Program Director, LNRGI [email protected]

Mr. Laurie E. Reed Geophysical Consultant, LNRGI Technical Manager [email protected]

INTELLECTUAL PROPERTY OPA on behalf of LNRGI

WORK PERFORMED • Ground Gravity survey: o at a reading interval of 1 km on accessible roads, trails and

lake edges; o at a reading interval of 250 m along the route of an east-

west pipeline and along other road segments as identified by the LNRGI Technical Manager during the course of the survey.

• Compilation of the existing network of gravity points to the newly acquired data and production of complete Bouguer Anomaly, Second Order Residual Anomaly and First Vertical Derivative maps.

GEOPHYSICAL OBJECTIVES • To increase the gravity coverage south and west of Lake

Nipigon. • To assist in the interpretation of the structure of the Nipigon

basin. • To map geological structures, particularly ultramafic bodies. • To investigate the connectivity of the diabase outliers at depth

and to provide more detail on the thickness of the Sibley sediments (with the help of detailed traverses).

• This report is restricted to the technical aspect of the survey and doesn’t encompass the interpretation aspect of the results.


GENERAL LOCATION OF THE SURVEY AREA

LNRGI Survey area


2. THE SURVEY AREA

LOCATION Lake Nipigon Embayment Area Northern Ontario

NTS 1/50 000 SHEETS 52H/1,2,3,4,5,6,7,8; 52A/13,14,15,16

AREA ~ 8 700 km 2

NEAREST SETTLEMENTS Thunder Bay: 60 km south Armstrong: at the north boundary Red Rock: at the south-east corner

ACCESS MEANS Trucks, ATV (fall 2003) and snowmobiles (winter 2004)

MAP TILE LAYOUT


3. SURVEY PROGRESS

ALLOCATED OFFICE PERSONNEL

Pierre Bérubé, Eng., Project manager François Dubé, GPS specialist Martin Dubois, Geo, Field and logistics manager Annie Lacasse, B.Sc., Data processing and drafting

FIELD CREW LEADERS Marc Bergeron Jacques Demers Alain Zubrzycki Michel Crépeau Paul Mélançon Patrick Allard Denis Leclerc

HELPERS (WINTER 2004) Jonathan Marcoux Greg Bastien

DATA ACQUISITION • Fall 2003: September 3 to November 28: Geodetic tie-in, gravity meter calibrations, base station establishment and reading of 3119 stations.

• Winter 2004: February 25 to March 24: 972 fill-in stations were read.

• A total of 4091 accepted stations were read in 196 crew-days for an average of 21 stations / crew-day.

• 65 stations (1.6%) were discarded due to poor GPS reception in heavily forested areas or hilly terrain.

2003-2004 Lake Nipigon Region Geoscience Initiative Gravity Survey

1714

804

1573

4091

6.9%7.3% 7.2% 7.1%

0

500

1000

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B C D Total

Gravity Meter ID

Stat

ions

0.0%

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6.0%

8.0%

10.0%

Re-

visi

ted

Stat

ions

Production Re-visited


BASES OF OPERATION • Red Rock (Base station -999) for the southern part of the survey

area, from September 3 to October 15, 2003. • Highway 527/811 (Base station -996) for the intermediate part

of the survey area. Two bush-camps were rented from October 15 to November 23, 2003.

• Armstrong (Base station -995) for the northern part of the survey area, from November 24 to 28, 2003.

• Nipigon (Base station -994) for the southern part of the survey area, for the winter fill-in campaign, from February 25 to March 10, 2004.

• Armstrong (Base station -995) to complete the coverage of the northern part of the survey area, from March 11 to 24, 2004.

WEATHER CONDITIONS The weather conditions during both phases may be considered as

normal for the fall and winter seasons in this area. Hurricane Isabel (September 19) did not prevent the crews from doing a normal production day.

SECURITY • Snow on October 24 caused an accident with one of the vehicle (no injury or damage to the equipment). Snow tires were installed on all trucks the day after.

• A crew chief was injured when hit in the face by a tree branch while driving an ATV. His helmet did not offer enough protection. He received immediate care at the Nipigon hospital. He was able to return to work (on another project) one week later with no permanent injuries. We replaced him immediately on the project by another crew chief.

• All crews were equipped with mobile radios and satellite phones.

ENVIRONMENT • No environmental incident to report. • We did respect the prohibited access on some Environmentally

Protected Areas.

UNEXPECTED DIFFICULTIES • The Nakina, Beardmore and Longlac CGSN primary control stations no longer exist. The third station used for calibration (Silver Dollar) was a 4-hour drive from our base of operation.

• Highway 527 was closed to traffic on October 28 (stand-by charges).

• Many roads or trails indicated on the maps were no longer practical. Many roads were closed to public (Bowater, Domtar, Abitibi Consolidated). Access was limited or prohibited on some First Nation Lands, Conservation Areas and Nature Reserves.

• In addition to the above, inaccessible mountainous areas contributed to an incomplete survey coverage.

• The observed residual instrumental drift was slightly higher than normal due to the lake loading effect (Nipigon and Superior Lakes), not accounted for in the tidal correction.


4. GPS ACQUISITION

TYPE OF SURVEY Rapid static GPS surveying from a known geodetic point with an expected accuracy better than 1 m in horizontal position and 0.25 m in elevation.

INSTRUMENTATION Base station : Two Leïca 300 SR9500 Sensors : s/n 1402 & 1511 CR344 Controllers : s/n 273180 & 283345 Mobile : Three Leïca SR530 SR530 Sensors : s/n 135735, 130882 & 0038421 TR500 Controllers : s/n 23439, 22582 & 24513 All the Leïca units are dual frequency (L1 & L2) with phase measurements in order to maximize the number of observations, thereby improving the resolution of ambiguities.

SOFTWARE SKI-Pro 3.0 from Leïca

COORDINATE SYSTEM Projection: Universal Transverse Mercator Datum: NAD83 Central meridian: 87°00’ W (UTM Zone 16N) Central scale factor: 0.9996 False easting: 500 000 m False northing: 0 m Ellipsoid: WGS 1984 Geoid model: CGG 2000

GPS BASE STATION A total of 43 secondary GPS base stations were established in the survey area. These stations were used for the duration of the survey and were not monumented. Usually, two of these GPS base stations were simultaneously recording in a given area. They recorded dual frequency time-tagged information from the satellite signal for post-processing.


The geodetic point 00819990085, located on highway 11, has been adopted as our base point and has been verified with the geodetic points 00819990084 and 00819990087. The results are as follows:

The planimetric coordinates are in the UTM projection, based on ellipsoid WGS 84. The orthometric elevations are calculated with the geoidal undulation model CGG2000. The following chart shows the difference between the calculated orthometric elevation, using the CGG2000 geoidal undulation model, and the orthometric elevation as given for the geodetic points by the Geodetic Service of Ontario and the government of Canada.

GEODETIC TIE-IN

The geodetic points 93U183 and 93U189 are first order altimetric points, based on the vertical datum CGVD28 (Canadian geodetic vertical datum 1928; average sea level; being the adopted altimetric reference system for Canada). From this we can apply a constant of -0.279 meter on the calculated altitude from the model CGG2000 and obtain results compatible with the Canadian Altimetric Reference System.

Theoretical Measured Delta

Base point 00819990085

North (Y): 5 441 215.081

East (X): 408 267.981

Ellipsoidal elevation: 159.262

Control point 00819990084

North (Y): 5 441 854.519 5 441 854.53 +0.011

East (X): 408 604.136 408 604.13 -0.006

Ellipsoidal elevation: 163.28 163.264 -0.016

Control point 00819990087

North (Y): 5 436 588.172 5 436 588.17 -0.002

East (X): 407 509.746 407 509.762 +0.016

Ellipsoidal elevation: 151.96 151.90 -0.060

Point number Calculated elevation

Theoretic elevation Delta Z

00819990084 200.333 200.023 +0.310

00819990085 196.325 196.001 +0.324

00819990087 188.939 188.687 +0.252

93U183 240.881 240.657 +0.224

93U189 269.322 269.038 +0.285

Mean: +0.279


GPS PROCESSING The data was transferred from the GPS PCMCIA cards to a computer

and processed after each survey day. The time-tagged information recorded by the mobile receiver and the base receiver was processed and the coordinates calculated.

GPS QCS Before the survey: The five GPS units were verified against three provincial

calibration benchmarks in Val-d’Or. Level and graduated staff accuracies were checked.

During the survey: The distance was measured between the antenna and the

ground, to a precision of 1 millimetre, and was entered on the keypad.

The gravity station numbers were automatically incremented on the keypad-display unit, this number was checked against the number recorded in the gravity meter.

Time-tagged information from the satellites was recorded for a period of about 7 minutes, from a distance of no more than 30 km from a GPS base station. As the base station is taking a reading every 5 seconds (GPS satellite clock), the mobile and base units record information simultaneously for the duration of the reading.

At the Base of Operations: Re-occupied stations were processed daily to identify any

weakness in the survey method. 290 stations out of 4091 (7.1%) were repeated:

Horizontal Position Elevation

Average repeat error 0.16 m 0.05 m (SD = 0.09 m)

Contract requirement 1.00 m 0.25 m


5. GRAVITY ACQUISITION

TYPE OF SURVEY Reconnaissance gravity survey with an expected accuracy better than 0.05 mGal in the absolute gravity.

INSTRUMENTS USED Type: Scintrex CG-3M Autograv Reading resolution: 0.001 mGal (digital recording) Serial numbers: 0004484 (B), 9709482 (C) & 9704368 (D) Seismic filter: enabled Continuous tilt correction: disabled Auto rejection: enabled (threshold is 6 x SD with seismic filter on) Tide correction: enabled Read time: 2 to 4 cycles of 60 seconds Info A: plateau height above ground After a heating and stabilization period of 48 hours, a calibration run was done for the three meters using the following CGSN primary stations.

CALIBRATION

These stations show a ∆gMAX of 116 mGal. The following constants were found:

SOFTWARE GRAVMOY (Abitibi Geophysics) for field QC and pre-processing IDUMP (Geosoft DOS) for data transfer to a PC Xcelleration (Oasis Montaj module from Geosoft) for all remaining gravity processing, including terrain correction. Oasis Montaj Processing Engine and Magmap 2D FFT for gridding and filtering.

Date Meter K (mGal / unit) Error

Sept. 05 B 0.9991 0.0002

Sept. 21 C 1.0006 0.0001

Sept. 05 D 1.0009 0.0001

ID Name G (mGal) 9381-1998 TB Airport 980802.582 ± 0.004

9239-1976 Pearl River 980822.410 ± 0.020

9021-1974 Silver Dollar 980918.670 ± 0.015


BASE STATIONS A total of 6 gravity base stations were established in the survey

area. Two to eight tie-ins were performed for each of these bases:

The largest errors associated with Base Station -995 (Armstrong) are inherent to long travel distance and poor road conditions. We recommend in the future that such remote base stations be tied using a helicopter. A complete description of each base station is provided on the following specification sheets.

Base ID Name Date Meter Closing Errors Repeat Report

-999 Red Rock Sept. 6, 2003 Sept. 6, 2003

B D

1, 3 µGal 1, 23 µGal

1 µGal 6 µGal

-998 Pipeline Sept. 16, 2003 B 1, 7 µGal 2 µGal

-997 Kabitotikwia Oct. 8, 2003 Oct. 21, 2003 Oct. 8, 2003

Oct. 21, 2003

B B D D

33, 73 µGal 13, 11 µGal 33, 73 µGal 13, 11 µGal

1 µGal 4 µGal 1 µGal 4 µGal

-996 Roads 527/811 Oct. 21, 2003 B 13, 11 µGal 1 µGal

-995 Armstrong Nov. 23, 2003 Nov. 23, 2003

D D

85, 17 µGal 88, 11 µGal

13 µGal 26 µGal

-994 Pine Crest Feb. 25, 2004 B 43, 0 µGal 3 µGal


Ontario Prospectors Association Red Rock Gravity Base Station (-999)

Station number: -999

Name: Red Rock

Area: Nipigon Lake

NTS sheet: 52A/16

Geodetic system: WGS 84, UTM Zone 16

Longitude: 88° 15' 30.53" W

Latitude: 48° 56' 14.93" N

Easting: 407 837.4 ± 0.2 mE

Northing: 5 421 269.0 ± 0.2 mN

Elevation (CGG2000): 203.11 ± 0.05 m

gABS 980 872,041 ± 0.001 mGal

Primary station: Pearl River (CGSN)

Gravity meter: CG-3M units B & D

Positioning: DGPS (Leica SR530)

The station is located on a concrete porch at the back entrance of an apartment building located at 10 Frost Street East in Red Rock, Ontario.

37 cm

45 cm


Ontario Prospectors Association Pipeline Gravity Base Station (-998)


Name: Pipeline

Area: Nipigon Lake

NTS sheet: 52H/2

Co-ordinate system: WGS 84, UTM Zone 16

Longitude: 88° 37' 23.21" W

Latitude: 49° 06' 29.48" N

Easting: 381 540.9 ± 0.2 mE

Northing: 5 440 751.3 ± 0.2 mN

Elevation (CGG2000): 249.94 ± 0.05 m

gABS 980 885.689 ± 0.002 mGal

Primary station: Pearl River (CGSN)

Gravity meter: CG-3M unit B


The station is located on the Black Sturgeon River road, 34 km north of the junction with Highway 11/17. It lies under a power line, on the west edge of that gravel road.

Power Line

Bush

Cleared area due to the natural gas pipeline

10 m

10 m

-998●● ●

Electric Pole

Bush

Bla

ck S

turg

eon

R

iver

Roa

d

N


Ontario Prospectors Association Kabitotikwia Gravity Base Station (-997)


Name: Kabitotikwia

Area: Nipigon Lake

NTS sheet: 52H/11

Geodetic system: WGS 84, UTM Zone 16

Longitude: 89° 10' 49.03" W

Latitude: 49° 35' 52.28" N

Easting: 342 451.9 ± 0.2 mE

Northing: 5 496 203.3 ± 0.2 mN

Elevation (CGG2000): 285.57 ± 0.05 m

gABS 980 925,494 ± 0.002 mGal

Primary Station: Thunder Bay Airport (CGSN)



The station is located along road 527, 146 km north of the junction with Highway 11/17. It lies 400 m north of the Kabitotikwia River bridge, 12 m east of the paved edge of road 527.

-997

527

Armstrong

Thunder Bay

Gas

12 m

400

m

Kabitotikwia River

N


Ontario Prospectors Association Roads 527/811 Gravity Base Station (-996)


Name: Roads 527/811

Area: Lake Nipigon

NTS sheet: 52H/6


Longitude: 89° 22' 43.76" W

Latitude: 49° 21' 41.93" N

Easting: 327 277.6 ± 0.2 mE

Northing: 5 470 381.2 ± 0.2 mN

Elevation (OSU91A): 449.36 ± 0.05 m

gABS 980 863,346 ± 0.001 mGal

Primary station: Thunder Bay Airport (CGSN)



This station is located along road 527, 114 km north of the junction with Highway 11/17. It lies 800 m from road 811, 200 m west of road 527, on the south-east corner of a concrete base.

-996

N


Ontario Prospectors Association Armstrong Gravity Base Station (-995)


Name: Armstrong

Area: Lake Nipigon

NTS sheet: 52I/6


Longitude: 89° 02' 21.06" W

Latitude: 50° 18' 07.52" N

Easting: 354 781.1 ± 0.2 mE

Northing: 5 574 207.9 ± 0.2 mN

Elevation (OSU91A): 343.33 ± 0.05 m

gABS 981 005,74 ± 0.02 mGal

Primary station: -996 & -997

Gravity meter: CG-3M units D


The station is located at the back of the Chateau-North Hotel in Armstrong. It lies on a concrete floor in front of the neighbour's garage.

Concrete slab


Ontario Prospectors Association Pine Crest Gravity Base Station (-994)


Name: Pine Crest

Area: Lake Nipigon

NTS sheet: 52H/1


Longitude: 88° 17' 16.77" W

Latitude: 49° 01' 20.22" N

Easting: 405 836.3 ± 0.2 mE

Northing: 5 430 732.0 ± 0.2 mN

Elevation (CGG2000): 259.21 ± 0.05 m

gABS 980 872.982 ± 0.003 mGal

Primary station: -999 (Red Rock)

Gravity meter: CG-3M units B


The station is located at Pine Crest Motel in Nipigon, on the north side of Highway 11/17. It lies on the left corner of the first concrete step leading to the motel door.

Highway 11-17

Pine Crest Motel Nipigon

-994

ONTARIO PROSPECTORS ASSOCIATION - 17 - LNRGI / 03N718

FIELD PROCEDURES Each loop began and ended with a reading at a base station.

Readings were also taken at mid-day whenever possible. These readings were used to calculate the instrumental drift, and the drift correction was linearly applied to the data in the loop. At each station, the following parameters were recorded in the field notebook:

• Station identification • Instrument readings • Local time • Instrument height above ground • Slopes to the centre of each of four sectors of Hammer zones

B (2-12 m) and C (12-50 m). The following data were recorded in the instrument’s memory:

• Station identification • Instrument readings • Local time • The standard deviation of each reading • Tilt about the X axis in arc-seconds, at the end of the • reading • Tilt about the Y axis in arc-seconds, at the end of the • reading • The number of samples that were read • The number of rejected samples • The gravity sensor temperature compensation factor The first step was to locate the most appropriate site for both GPS and gravity readings. During winter, a wooden base was firmly placed on the snow and the meter's tripod securely stabilized on it. The gravity meter was then placed on the tripod and the meter was levelled with the levelling screws on the tripod before the reading was initiated; the operator stayed still to avoid inducing ground motion that could affect the gravity meter. The gravity meter was put in its padded and insulated carrying bag immediately after each station. After each survey day, the data was downloaded from the CG-3M gravity meter through an RS232 cable to a computer serial port. The Geosoft IDUMP program was used to transfer the data.


GRAVITY QCS Before the survey:

The gravity meter had been heated and stabilized for more than 48 hours.

All the internal constant values had been checked. Temperature compensation had been fine-tuned to ± 0.1 mGal/mK. The X and Y tilt sensitivities had been checked and did not require

any adjustments. During the survey:

The drift was controlled after each loop. The absolute average closure error is:

Drift (mGal)

Contract Requirements

Meter B Meter C Meter D

Per loop 0.100 0.044 0.043 0.073

Per hour 0.020 0.004 0.005 0.008

The residual cumulative drift charts are presented on the next pages. The apparent larger residual drift of meter D is simply due to an Internal Drift Constant that should have been adjusted. The Internal Drift Constant being a linear compensation, a poor adjustment won’t affect data quality after the residual drift correction; it simply looks better when the Internal Drift Constant do its job of compensating most of the normal unidirectional instrumental drift.

During the readings, the operator observed the levels to make sure that the instrument stayed at level, well within a ± 20 arcsec range.

At least two readings were taken at every station. A third and even fourth one was recorded if the first two were more than 0.01 mGal apart.

At the Base of Operations: Dump files (YYMMDDG.ori) were inspected to detect any spurious

readings, for instance: - reading time < 60 seconds - rejected samples > 5 - standard deviation > 0.1 mGal

Repeated readings at the same station were then averaged with GRAVMOY using the inverse of the standard deviation as a weighting factor (YYMMDDG.dmp files).

290 stations out of 4091 (7.1%) were re-occupied in a different loop.

The average repeat error was 0.011 mGal and the standard deviation was 0.013 mGal.

ABSOLUTE GRAVITY (gA) The averaged observed gravity values (YYMMDDG.dmp files) that

were processed using GRAVMOY were first imported into Geosoft Xcelleration along with the elevation data. Note that the standard deviation on the weighted average of the observed gravity was less than 0.010 mGal.

Tidal correction is re-calculated in Xcelleration using the station location and average measuring time. The accuracy of this correction is better than 0.001 mGal.


The value of the instrument height is typically accurate within ±

1 cm or ± 0.003 mGal. The residual drift of the gravimeter is assumed linear between two readings at the base station. The closure error was linearly distributed on the data in the corresponding loop, taking into account the instrument height and the tidal correction. Non-linear drifting could introduce an error of up to 0.010 mGal in the middle of a loop.

The maximum error on gA is therefore estimated to be ± 0.033 mGal, which agrees with the observed maximal error on re-visited station: 0.029 mGal at station 3962. This is better than required accuracy of 0.05 mGal as per the contract.

LNRGI Gravity Survey - Residual Cumulative Drift - Gravity Meter B

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LNRGI Gravity Survey - Residual Cumulative Drift - Gravity Meter C

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LNRGI Gravity Survey - Residual Cumulative Drift - Gravity Meter D

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BOUGUER ANOMALY (gB) Density “σ”: a 2.67 g/cm3 local crustal density was taken for the Bouguer and Terrain corrections. Latitude Correction: both the rotation of the Earth and its slight equatorial bulge produce an increase of gravity with latitude. This effect is corrected when computing the theoretical value of gravity at the surface of the reference ellipsoid using the Geodetic Reference System GRS67:

gL (φ) = 978 031.846 {1.0+0.005278895 sin2 (φ) + 0.000023462 sin4 (φ)} mGal

The horizontal position is accurate to better than ± 16 cm, so the error is less than 0.001 mGal. Free Air Anomaly: since gravity varies with the inverse of distance squared, it is necessary to correct for changes in elevation between stations so that all field readings are reduced to a datum surface. The Free Air anomaly at elevation “h” is:

gF = gA - gL + 0.308596 * h Bouguer Anomaly: it accounts for attraction of material of density “σ” between the station and the datum plane, which was ignored in the Free Air calculation. The Bouguer anomaly is:

gB = gF - 0.0419088 * σ * h

Using a density of 2.67 and a global accuracy of ± 5 cm in elevation, the error on the combined Free Air and Bouguer correction is ± 0.010 mGal.

ACCURACY OF gB

TERRAIN CORRECTION It allows for surface irregularities in the vicinity of the station, not accounted for in the Bouguer calculation. An excess mass in the form of a positive topographic feature adjacent to a gravity station exerts an upward pull on the gravity meter, thus lowering the observed reading. A mass deficiency in the form of a valley adjacent to a gravity station causes the gravity field to be lower than it would be where the terrain is flat. Terrain corrections compensate for these effects and are therefore always positive.

Error (mGal) Step Source/Evaluation

Method Maximal Typical

gA Re-occupied stations 0.033 0.011

gL Latitude correction 0.001 0.000

gB Free Air and Bouguer 0.010 0.010

Estimated error on gB * 0.13 0.021

Contract requirement * 0.20

* excluding terrain correction


INNER TERRAIN

CORRECTION The terrain effect up to 50 m from the station was evaluated in the field by measuring the absolute height difference in each of the four sectors for the Hammer zones B and C.

The terrain correction was then calculated using Hammer’s formula (Hammer 1939):

gT = γ * σ * θ *

−−−+− 22

222

112 zrzrrr

Where γ = 0.00667 Nm2/g2 θ = sector angle (radians) σ = density (2.67) r1, r2 = inner and outer sector radii Z = average height difference between the station and the sector

Zone B Zone C r1: 2 m 12 m r2: 12 m 50 m Number of sectors: 4 (θ = 1.57) 4 (θ = 1.57)

OUTER TERRAIN CORRECTION

• A 50 m cell size digital elevation model (DEM) was provided by Mr. Desmond Rainsford, geophysicist at the Ontario Geological Survey in Sudbury ([email protected]). This DEM was derived from the Endeavour Shuttle Radar Topography Mission (SRTM) elevation database with a 90 m horizontal resolution and a relative vertical height accuracy better than 10 m.

• The corrections were calculated with the Terrain Correction module of the Xcelleration package built in the Geosoft Montaj processing engine. The DEM is sampled to a grid mask centred on the station to be calculated. The correction is performed based on near zone, intermediate zone and far zone contributions: o The near zone is one cell from the station (50 m). This

contribution has already been taken into account in the inner Hammer correction described earlier.

o In the intermediate zone (50 to 400 m from de station), the terrain effect is calculated for each point using the flat-topped square prism approach of Nagy (1966).


o In the far zone (farther than 400 m), the terrain

effect is based on the annular ring segment approximation to a square prism described by Kane (1962). No optimization of the prism size were performed to reduce processing time.

o The correction was applied to a distance of 30 km from each station. Beyond this distance, the terrain effect is negligible (a test done with an outer distance of 20 km resulted in a decrease of the average correction of only 3.9%).

FINAL CONTROL The final quality assurance and quality control were performed by Mr. Laurie E. Reed, Geophysical Consultant and LNRGI Technical Manager.


6. COMPILATION AND DELIVERABLES

BITTERROOT DATABASE A 698-gravity point database was supplied by Bitterroot Resources Ltd of Vancouver, B.C. The survey results were not tied to the CGSN but assumed to have been processed by applying the same standard corrections described in chapter 5 of this report. Readings were taken at a 500 m interval along roads and trails west of the Black Sturgeon Road and mostly north of the pipeline. Because the segments of the Black Sturgeon Road and of the pipeline route were part of the planned 250 m spacing detailed profiles, we completely re-surveyed these segments in order to level the Bitterroot survey with the data of the present campaign (that is, to tie it to the CGSN). A constant of 69.2 mGal had to be subtracted from the Bitterroot Bouguer values. Where stations from both surveys are less than 50 m apart on the map, most of the Bitterroot levelled Bouguer values agrees to within ±0.01 mGal with the new LNRGI corresponding value. The Bitterroot database also contains detailed readings at a 25 m spacing along survey lines. These were decimated to 150 m for clarity purposes on the final maps. A total of 264 readings are merged into the LNRGI database. These stations are posted as a white triangle on the maps. The projection was converted from NAD 27 to NAD 83.

OGS DATABASE A 970-gravity point database was supplied by the OGS. Nominal spacing between readings is usually 10 km. Only the data points located outside the LNRGI survey were kept to help define the regional anomaly. Approximately 60 of these points are within the map outlines; they are posted as a white square on the maps.

BASE MAP The layout design of the two 1:100,000 scale map tiles covering the survey area was provided by the OGS. The planimetric base maps incorporating relevant geographic references (UTM coordinates, latitude/longitude, township boundaries), index map and some descriptive notes were also supplied by the OGS in agreement with the LNGRI representatives.

BOUGUER ANOMALY MAP The newly acquired database merged with the above-described archive was gridded using a minimum curvature algorithm with a tolerance of 0,01 mGal for each grid cell, a grill cell size of 300 m and a blanking distance of 25 km. One pass of a 3 x 3 Hanning filter was applied before contouring. Three different line weights and intervals (0.5, 2 and 10 mGal) were used for the contours.


RESIDUAL ANOMALY MAP A residual anomaly was obtained by subtracting a second order

least-squares surface from the Bouguer anomaly. This surface, representing the regional anomaly, was adjusted using all points of the Bouguer grid.

FIRST VERTICAL DERIVATIVE MAP

The vertical gradient grid (i.e. first vertical derivative) wascomputed from the 2nd order residual anomaly in order to enhance the response due to near-surface features, and to improve source resolution and delineation. Filtering was performed in the frequency (wave-number) domain. One pass of a 3 x 3 Hanning filter was then applied and the resulting grid coloured with a standard colour table with linear intervals of 0.1 µGal/m from -2.5 to 2.5 µGal/m.

MAPS PRODUCTS Ten copies of the following colour maps are delivered with this report. Our Quality System requires that every final map be inspected by at least two qualified persons before being approved and included within a final report.

Map Number Description Scale

81 930 Ground Gravity Survey – Terrain-Corrected Bouguer Anomaly Southern Part, Lake Nipigon Embayment Area

1:100,000

81 931 Ground Gravity Survey – Terrain-Corrected Bouguer Anomaly Northern Part, Lake Nipigon Embayment Area

1:100,000

81 932 Ground Gravity Survey – First Vertical Derivative of the Terrain-Corrected Bouguer Anomaly Southern Part, Lake Nipigon Embayment Area

1:100,000

81 933 Ground Gravity Survey – First Vertical Derivative of the Terrain-Corrected Bouguer Anomaly Northern Part, Lake Nipigon Embayment Area

1:100,000

81 934 Ground Gravity Survey – Residual of the Terrain-Corrected Bouguer Anomaly Southern Part, Lake Nipigon Embayment Area

1:100,000

81 935 Ground Gravity Survey – Residual of the Terrain-Corrected Bouguer Anomaly Northern Part, Lake Nipigon Embayment Area

1:100,000


DIGITAL DATA PRODUCTS • A copy of all calibration data, survey acquisition data, GPS

and gravity-processed data are delivered in ASCII text format on CD-Rom.

• The final LNRGI gravity database is delivered in Geosoft Oasis Montaj format (03N718_Master.gdb) along with the other accessory databases on CD-Rom.

• The above-described maps are delivered in the Oasis Montaj map file format on CD-Rom.

OTHER DELIVERABLES All field books and field maps used during the course of the

project were also delivered to the OPA.

Respectfully submitted, Abitibi Geophysics Inc.

Pierre Bérubé, Eng. Geophysicist PB/da


7. References

Briggs, I.C. 1974. Machine contouring using minimum curvature; Geophysics, v.39, p.39-48. Hammer, S. 1939. Terrain corrections for gravimeter stations; Geophysics, v.4, p.184-194. Kane, M.F. 1962. A comprehensive system of terrain corrections using a digital computer; Geophysics, v.27, p.455-462 Nagy, D. 1966. The prism method for terrain corrections using digital computers; Pure and Applied Geophysics, v.63, p.31-39. Wollard, G.P. 1979. The new gravity system – changes in international gravity base values and anomaly values; Geophysics, v.44, p.1352-1366.

APPENDIX A

TABLES


PRODUCTION AND REPEATS - Meter: B Gravity Revisited Stations DATE

(yyyy-mm-dd) Stations

Read Stations

Up to now Number Up to now % Station # Read

Stations removed due to poor GPS data

Operator

03-09-07 24 24 0 0 0.0% 1000-1023 MB, MD 03-09-08 17 41 1 1 2.4% 1024-1040 MD 03-09-09 3 44 0 1 2.3% 1041-1043 MB, FD 03-09-10 44 1 2.3% cycling 03-09-11 25 69 2 3 4.3% 1044-1068 MD,JD 03-09-12 19 88 1 4 4.5% 1069-1087 JD 03-09-13 12 100 1 5 5.0% 1088-1102 1088, 1089, 1090 JD 03-09-14 6 106 0 5 4.7% 1103-1108 JD

03-09-15 10 116 1 6 5.2% 1109-1118 1091, 1102, 1036 re-read because the GPS base was down the first time.

JD

03-09-16 116 6 5.2% Base -998 03-09-17 25 141 2 8 5.7% 1119-1143 JD 03-09-18 29 170 2 10 5.9% 1144-1172 JD 03-09-19 23 193 2 12 6.2% 1173-1195 JD 03-09-20 21 214 2 14 6.5% 1196-1216 JD,PA 03-09-21 23 237 2 16 6.8% 1217-1239 JD,PA 03-09-22 23 260 2 18 6.9% 1240-1262 JD 03-09-23 23 283 2 20 7.1% 1263-1285 JD 03-09-24 13 296 1 21 7.1% 1286-1298 JD 03-09-25 12 308 1 22 7.1% 1299-1310 JD 03-09-26 22 330 2 24 7.3% 1311-1332 JD 03-09-27 18 348 2 26 7.5% 1333-1350 JD 03-09-28 15 363 1 27 7.4% 1351-1365 JD 03-09-29 19 382 2 29 7.6% 1366-1385 JD 03-09-30 14 396 1 30 7.6% 1385-1399 1391 JD 03-10-01 20 416 2 32 7.7% 1400-1419 JD 03-10-02 17 433 1 33 7.6% 1420-1436 JD 03-10-03 13 446 1 34 7.6% 1437-1449 JD 03-10-04 20 466 2 36 7.7% 1450-1470 1450 JD 03-10-05 21 487 2 38 7.8% 1471-1491 JD 03-10-06 27 514 2 40 7.8% 1492-1519 1493 JD 03-10-07 29 543 2 42 7.7% 1520-1548 JD 03-10-08 33 576 2 44 7.6% 1549-1581 JD 03-10-09 14 590 1 45 7.6% 1582-1595 JD 03-10-10 22 612 2 47 7.7% 1596-1617 JD 03-10-11 22 634 2 49 7.7% 1618-1640 1626 JD 03-10-12 5 639 0 49 7.7% 1641-1647 1643, 1644 JD 03-10-13 18 657 1 50 7.6% 1648-1665 JD 03-10-14 20 677 2 52 7.7% 1666-1685 JD 03-10-15 21 698 1 53 7.6% 1686-1706 JD 03-10-17 18 716 2 55 7.7% 1707-1724 JD

APPENDIX A

TABLES




Read Stations



Operator

03-10-18 16 732 1 56 7.7% 1725-1740 JD 03-10-19 24 756 2 58 7.7% 1741-1765 1760 JD 03-10-20 17 773 2 60 7.8% 1766-1782 JD 03-10-21 773 60 7.8% New Base JD 03-10-22 24 797 2 62 7.8% 1783-1806 JD 03-10-23 19 816 1 63 7.7% 1807-1825 JD 03-10-24 15 831 1 64 7.7% 1826-1840 JD 03-10-25 14 845 1 65 7.7% 1841-1854 JD 03-10-26 20 865 1 66 7.6% 1855-1874 JD 03-10-27 18 883 1 67 7.6% 1875-1892 JD 03-10-28 4 887 0 67 7.6% 1893-1896 JD 03-10-29 22 909 2 69 7.6% 1897-1922 1917, 1919, 1920, 1921 MB 03-10-30 14 923 1 70 7.6% 1923-1942 1937, 1938, 1939, 1940,

1941, 1942 MB 03-10-31 3 926 0 70 7.6% 1943-1946 1946 PS,MB 03-11-01 8 934 0 70 7.5% 1947-1954 PS 03-11-02 11 945 1 71 7.5% 1955-1965 PS

945 0 71 7.5% 03-11-04 2 947 0 71 7.5% 1966-1967 PS 03-11-05 20 967 2 73 7.5% 1968-1987 PS 03-11-06 14 981 1 74 7.5% 1988-2001 PS 03-11-07 20 1001 2 76 7.6% 2002-2021 PS 03-11-08 11 1012 0 76 7.5% 2022-2032 PS 03-11-09 19 1031 2 78 7.6% 2033-2051 PS 03-11-10 10 1041 1 79 7.6% 2052-2061 PS 03-11-11 9 1050 1 80 7.6% 2062-2070 PS 03-11-15 17 1067 0 80 7.5% 2071-2087 PT 03-11-16 17 1084 1 81 7.5% 2088-2104 PT 03-11-17 14 1098 1 82 7.5% 2105-2118 PT 03-11-18 19 1117 1 83 7.4% 2119-2137 PT 03-11-19 29 1146 2 85 7.4% 2138-2166 PT

03-11-20 10 1156 1 86 7.4% 2167-2188 2172, 2173, 2179, 2180, 2181, 2182, 2183, 2184, 2185, 2186, 2187, 2188

PT

03-11-21 19 1175 2 88 7.5% 2189-2207 PT 03-11-22 16 1191 1 89 7.5% 2208-2223 PT 03-11-23 15 1206 1 90 7.5% 2224-2238 PT

1206 0 90 7.5% 03-11-25 25 1231 0 90 7.3% 2239-2263 PT 03-11-26 21 1252 1 91 7.3% 2264-2284 PT 03-11-27 16 1268 2 93 7.3% 2285-2300 PT 03-11-28 14 1282 1 94 7.3% 2301-2314 PT 04-02-26 14 1296 0 94 7.3% 2500-2513 MB 04-02-27 13 1309 1 95 7.3% 2514-2526 MB

APPENDIX A

TABLES




Read Stations



Operator

04-02-28 8 1317 1 96 7.3% 2527-2534 MB 04-02-29 22 1339 1 97 7.2% 2535-2556 MB 04-03-01 7 1346 1 98 7.3% 2557-2563 MB 04-03-02 15 1361 1 99 7.3% 2564-2578 MB 04-03-03 4 1365 1 100 7.3% 2579-2582 MB 04-03-04 8 1373 1 101 7.4% 2583-2590 MB 04-03-05 14 1387 1 102 7.4% 2591-2604 MB 04-03-06 6 1393 1 103 7.4% 2605-2611 2605 MB 04-03-07 25 1418 0 103 7.3% 2612-2636 MB 04-03-08 15 1433 1 104 7.3% 2637-2651 MB 04-03-09 12 1445 1 105 7.3% 2652-2663 MB 04-03-10 17 1462 0 105 7.2% 2664-2680 MB 04-03-12 12 1474 1 106 7.2% 2681-2692 MB 04-03-13 22 1496 1 107 7.2% 2693-2714 MB 04-03-14 26 1522 1 108 7.1% 2715-2740 MB 04-03-15 19 1541 1 109 7.1% 2741-2759 MB 04-03-16 17 1558 0 109 7.0% 2760-2776 MB 04-03-17 12 1570 1 110 7.0% 2777-2788 MB 04-03-18 10 1580 1 111 7.0% 2789-2798 MB 04-03-19 23 1603 1 112 7.0% 2799-2821 MB 04-03-20 15 1618 2 114 7.0% 2822-2836 MB 04-03-21 7 1625 1 115 7.1% 2837-2843 MB 04-03-22 35 1660 1 116 7.0% 2844-2878 MB 04-03-23 31 1691 1 117 6.9% 2879-2909 MB 04-03-24 23 1714 1 118 6.9% 2910-2932 MB

APPENDIX A

TABLES


PRODUCTION AND REPEATS - Meter: C Gravity Revisited Stations DATE


Read Stations



Operator

03-09-22 16 16 1 1 6% 3226-3241 PA 03-09-23 12 28 2 3 11% 3242-3253 5 stations re-read - poor

GPS on Sept 22 PA 03-09-24 1 29 0 3 10% 3254 PA 03-09-25 11 40 3 6 15% 3255-3266 3259 doesn't exist PA 03-09-26 18 58 1 7 12% 3259 + 3267-3283 3267 gravi only, gps on

Sept 25 PA 03-09-28 22 80 2 9 11% 3284-3305 PA 03-09-29 3 83 0 9 11% 3306-3308 PA 03-09-30 16 99 1 10 10% 3309-3324 PA 03-10-01 1 100 0 12 12% 3325 PA 03-10-05 14 114 1 11 10% 3326-3340 3333 MC 03-10-06 15 129 1 12 9% 3341-3355 MC 03-10-07 25 154 2 14 9% 3356-3380 MC 03-10-08 30 184 2 16 9% 3381-3410 MC 03-10-09 22 206 2 18 9% 3411-3432 MC 03-10-10 18 224 1 19 8% 3433-3450 MC 03-10-11 24 248 2 21 8% 3451-3474 MC 03-10-12 18 266 1 22 8% 3475-3495 3488, 3489, 3490 MC 03-10-13 15 281 1 23 8% 3496-3510 MC 03-10-14 17 298 1 24 8% 3511-3527 MC 03-10-15 22 320 1 25 8% 3528-3549 MC 03-10-17 23 343 1 26 8% 3550-3572 MC 03-10-18 16 359 1 27 8% 3573-3588 MC 03-10-19 18 377 1 28 7% 3589-3606 MC 03-10-20 26 403 2 30 7% 3607-3632 MC 03-10-21 24 427 2 32 7% 3633-3656 MC 03-10-22 13 440 1 33 8% 3657-3669 MC 03-10-23 21 461 2 35 8% 3670-3690 MC 03-10-24 6 467 0 35 7% 3691-3696 MC 03-10-25 21 488 2 37 8% 3697-3717 MC 03-10-26 15 503 1 38 8% 3718-3732 MC 03-10-27 12 515 1 39 8% 3733-3744 MC 03-10-28 13 528 1 40 8% 3745-3757 MC 03-10-29 22 550 2 42 8% 3758-3782 3774, 3780, 3782 MC

03-10-30 13 563 1 43 8% 3783-3809 3785, 3786, 3793, 3796, 3797, 3798, 3800,3801, 3802, 3805, 3806, 3807, 3808, 3809

MC

03-10-31 12 575 1 44 8% 3810-3821 MC 03-11-01 22 597 2 46 8% 3822-3843 MC 03-11-02 20 617 1 47 8% 3844-3863 MC 03-11-03 17 634 1 48 8% 3864-3880 MC 03-11-04 15 649 1 49 8% 3881-3895 MC

APPENDIX A

TABLES


PRODUCTION AND REPEATS - Meter: C Gravity Revisited Stations DATE


Read Stations



Operator

03-11-05 25 674 2 51 8% 3896-3920 MC 03-11-06 12 686 1 52 8% 3921-3932 MC 03-11-08 24 710 2 54 8% 3933-3956 MC 03-11-09 14 724 1 55 8% 3957-3970 MC 03-11-10 3 727 0 55 8% 3971-3973 MC 03-11-11 8 735 0 55 7% 3974-3981 MC 03-11-12 27 762 2 57 7% 3982-4008 MC 03-11-23 3 765 0 57 7% 4009-4011 JD 03-11-25 3 768 0 57 7% 4012-4014 MB 03-11-27 20 788 1 58 7% 4015-4034 MB 03-11-28 16 804 1 59 7% 4035-4050 MB

APPENDIX A

TABLES


PRODUCTION AND REPEATS - Meter: D

Gravity Revisited Stations DATE (yyyy-mm-dd)

Stations Read

Stations Up to now Number Up to now %

Stations # read Stations removed

due to poor GPS data

Operator

03-09-07 19 19 0 0 0% 5001-5019 PB, FD 03-09-08 19 38 1 1 3% 5020-5038 FD,MB 03-09-09 12 50 1 2 4% 5039-5050 MD 03-09-10 18 68 1 3 4% 5051-5068 MD,JD 03-09-11 68 3 4% cycling 03-09-12 25 93 2 5 5% 5069-5093 MD 03-09-13 8 101 1 6 6% 5094-5101 MD 03-09-14 20 121 2 8 7% 5102-5121 MD 03-09-15 16 137 1 9 7% 5122-5137 MD 03-09-16 18 155 1 10 6% 5138-5155 JD 03-09-17 28 183 2 12 7% 5156-5183 MD 03-09-18 20 203 2 14 7% 5184-5203 MD 03-09-19 22 225 2 16 7% 5204-5225 MD 03-09-20 23 248 2 18 7% 5226-5248 MD,PM 03-09-21 17 265 1 19 7% 5249-5265 PM 03-09-22 23 288 2 21 7% 5266-5288 PM 03-09-23 19 307 1 22 7% 5289-5307 PM 03-09-24 17 324 1 23 7% 5308-5324 PM 03-09-25 10 334 0 23 7% 5325-5334 PM 03-09-26 334 0 23 7% 03-09-27 13 347 1 24 7% 5335-5347 MB 03-09-29 5 352 0 24 7% 5348-5352 MB 03-09-30 2 354 0 24 7% 5353-5354 MB 03-10-01 19 373 1 25 7% 5355-5373 MB 03-10-02 13 386 1 26 7% 5374-5386 MB 03-10-03 13 399 1 27 7% 5387-5401 5391, 5392 MB 03-10-05 14 413 1 28 7% 5402-5415 MB 03-10-06 413 0 28 7% 03-10-07 6 419 1 29 7% 5416-5421 MB 03-10-08 419 0 29 7% 03-10-09 20 439 2 31 7% 5422-5441 MD 03-10-10 19 458 1 32 7% 5442-5460 MD 03-10-11 21 479 2 34 7% 5461-5481 MD 03-10-12 10 489 1 35 7% 5482-5491 MD 03-10-18 11 500 1 36 7% 5492-5502 AZ 03-10-19 12 512 1 37 7% 5503-5514 AZ 03-10-20 18 530 2 39 7% 5515-5533 5525 doesn't exist AZ 03-10-21 17 547 2 41 7% 5525 + 5534-5549 AZ 03-10-22 14 561 1 42 7% 5550-5563 AZ 03-10-23 20 581 2 44 8% 5564-5583 AZ 03-10-24 7 588 1 45 8% 5584-5590 AZ

APPENDIX A

TABLES




Stations Read




Operator

03-10-25 588 45 8% 03-10-26 16 604 2 47 8% 5591-5606 AZ 03-10-27 12 616 1 48 8% 5607-5618 AZ 03-10-28 12 628 1 49 8% 5619-5630 AZ 03-10-29 25 653 2 51 8% 5631-5655 AZ 03-10-30 21 674 2 53 8% 5656-5680 5659, 5678, 5679, 5680 AZ 03-10-31 674 53 8% 03-11-01 14 688 1 54 8% 5681-5694 AZ 03-11-02 16 704 2 56 8% 5695-5710 AZ 03-11-03 11 715 1 57 8% 5711-5721 AZ 03-11-04 22 737 2 59 8% 5722-5743 AZ 03-11-05 18 755 2 61 8% 5744-5761 AZ 03-11-06 20 775 2 63 8% 5762-5781 AZ 03-11-07 775 0 63 8% 03-11-08 15 790 2 65 8% 5782-5796 AZ 03-11-09 16 806 2 67 8% 5797-5812 AZ 03-11-10 5 811 1 68 8% 5813-5817 AZ 03-11-11 4 815 1 69 8% 5818-5821 AZ 03-11-12 11 826 0 69 8% 5822-5832 AZ 03-11-13 23 849 2 71 8% 5833-5855 AZ 03-11-14 21 870 2 73 8% 5856-5876 PT 03-11-15 16 886 2 75 8% 5877-5892 MB 03-11-16 4 890 1 76 9% 5893-5898 5891, 5892 MB 03-11-17 21 911 2 78 9% 5899-5919 MB 03-11-18 14 925 2 80 9% 5820-5933 MB 03-11-21 14 939 1 81 9% 5934-5948 5937 MB 03-11-22 18 957 2 83 9% 5949-5966 MB 03-11-25 26 983 1 84 9% 5967-5992 JD 03-11-26 20 1003 2 86 9% 5993-6012 JD 03-11-27 17 1020 2 88 9% 6013-6029 JD 03-11-28 14 1034 1 89 9% 6030-6043 JD 04-02-26 15 1049 0 89 8% 6050-6064 DL 04-02-27 17 1066 1 90 8% 6065-6081 6098 doesn't exist DL 04-02-28 25 1091 1 91 8% 6082-6107 DL 04-02-29 16 1107 1 92 8% 6108-6123 DL 04-03-01 15 1122 1 93 8% 6124-6138 DL 04-03-02 29 1151 1 94 8% 6139-6168 6141 doesn't exist DL 04-03-03 14 1165 1 95 8% 6169-6182 DL 04-03-04 17 1182 1 96 8% 6183-6199 DL 04-03-05 22 1204 1 97 8% 6200-6221 DL 04-03-06 18 1222 1 98 8% 6222-6239 DL 04-03-07 21 1243 1 99 8% 6240-6260 DL

APPENDIX A

TABLES




Stations Read




Operator

04-03-08 18 1261 1 100 8% 6261-6278 DL 04-03-09 20 1281 1 101 8% 6279-6298 DL 04-03-10 19 1300 1 102 8% 6299-6317 DL 04-03-12 20 1320 0 102 8% 6318-6337 DL 04-03-13 18 1338 1 103 8% 6338-6355 DL 04-03-14 13 1351 1 104 8% 6356-6368 DL 04-03-15 20 1371 1 105 8% 6369-6388 DL 04-03-16 19 1390 1 106 8% 6389-6407 DL 04-03-17 27 1417 0 106 7% 6408-6434 DL 04-03-18 25 1442 1 107 7% 6435-6459 DL 04-03-19 26 1468 1 108 7% 6460-6485 DL 04-03-20 15 1483 1 109 7% 6486-6500 DL 04-03-21 25 1508 1 110 7% 6501-6525 DL 04-03-22 20 1528 1 111 7% 6526-6545 DL 04-03-23 20 1548 1 112 7% 6546-6565 DL 04-03-24 25 1573 1 113 7% 6566-6590

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