Errata - Geophysical Data Sets

Geophysical Data Sets 1000 Series

In Geophysical Data Sets 1001-1006, 1009-1028, and 1031-1034 (released June 9, 2003), the following errors were noted. In the survey reports and documentation (Microsoft Word 97 (.doc) and Adobe Acrobat (pdf formats), any and all mentions of, or references to, the digital data series identifier (i.e., Geophysical Data Set 10xx-Revised or Geophysical Data Set 10xx rev) should exclude the word "Revised" or abbreviation "rev".

Geophysical Data Set 1014

Ontario Airborne Geophysical Surveys, Magnetic and Electromagnetic Data; Grid and Profile Data, ASCII and Geosoft® Formats, Matachewan Area

Original Release Date: June 8, 2003
Notification Date of Data Errata: June 2, 2008

An error in the co-ordinates for the EM anomaly database (both Geosoft® binary .gdb and ASCII .csv formats) has been identified. The error affects the NAD27 UTM co-ordinates, the NAD83 UTM co-ordinates and the NAD83 geographic (longitude and latitude) co-ordinates. The error can result in the EM anomalies being plotted near the equator. The NAD27 geographic co-ordinates in the database are unaffected by this error and are correct.

The EM anomaly database, in both binary and ASCII formats, has been updated and the erroneous co-ordinate values corrected.

Corrected Files

Path	File Name	File Size	Date Stamp	Time Stamp
EM_anomalies_binary\	MAANOMLY.gdb	4,806,656	16/04/2008	1:45p
EM_anomalies_ASCII\	Maanomaly.xyz	82,969	16/04/2008	1:43p

If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1035 and 1036

Geophysical Data Set 1035
Single Master Gravity and Aeromagnetic Data for Ontario, ASCII, Excel® and Access® Formats

Geophysical Data Set 1036
Single Master Gravity and Aeromagnetic Data for Ontario, Geosoft® Format

Original Release Date: July 12, 1999
Notification Date of Data Errata: December 9, 2014

An error was discovered in the Lambert Conformal Conic co-ordinates of the magnetic and gravity databases. The X co-ordinate values should have had 1 000 000 added to them. The latitude and longitude values are unaffected. Also, in the database of digitized aeromagnetic values, “ONDTZMAG”, it was found that the parameter names “EDITMAG” and “LEVMAG” had been switched. Both of these errors are present in Geophysical Data Set 1035 (ASCII format) and in Geophysical Data Set 1036 (Geosoft® binary format).

These errors have been corrected and replacement versions of these Geophysical Data Sets are available. If you purchased this product on CD, please contact Publication Sales and a replacement CD will be sent to you free of charge. Alternatively, you may visit the GeologyOntario application to obtain the corrected versions of GDS 1035 and GDS 1036.

We regret any inconvenience these errors may have caused.

Geophysical Data Set 1053

Discover Abitibi Kirkland Lake - Larder Lake Airborne Magnetic Survey

Original Release Date: November 15, 2004
Notification Date of Data Errata: November 25, 2004

A shift in the conventionally gridded magnetic data in the eastern part of the survey (Block 2) has resulted in the following errors in the digital products:

Geophysical Data Set 1053a ASCII grids klmagnad83.gxf, klmagnad27.gxf, kl2vdnad83.gxf and kl2vdnad27.gxf are displaced 222 metres south and 16 metres west in the eastern part of the grid. Clients are advised not to use these grids and use the gradient enhanced grids instead (i.e., klmaghgnad83.gxf, klmaghgnad27.gxf, kl2vdhgnad83.gxf and kl2vdhgnad27.gxf).

Geophysical Data Set 1053b Geosoft® format binary grids klmagnad83.grd, klmagnad27.grd, kl2vdnad83.grd and kl2vdnad27.grd are displaced 222 metres south and 16 metres west in the eastern part of the grid. Clients are advised not to use these grids and use the gradient enhanced grids in their place (i.e., klmaghgnad83.grd, klmaghgnad27.grd, kl2vdhgnad83.grd and kl2vdhgnad27.grd).

Geophysical Data Set 1079b

Ontario Airborne Geophysical Surveys, Magnetic and Electromagnetic Data, Grid and Profile Data (Geosoft® Format) and Vector Data, Kabinakagami Lake Area

Original Release Date: April 14, 2015
Notification Date of Data Errata: February 27, 2017

An error has been identified in the embedded zone for the UTM co-ordinates in the EM anomaly database (Geosoft® profile .gdb format), specifically in GDS 1079b volume 3. The UTM co-ordinates (x_nad83 and y_nad83) in profile database file KL2MAGEM.gdb are correct, but the embedded UTM zone was incorrectly assigned to Zone 16N instead of Zone 17N. The embedded zone information has been corrected.

Corrected Files

File name	File size	Date stamp	Time stamp
KL2MAGEM.gdb	3,823,809 Kb	01/09/2017	4:13 PM

Please note, because of the large size of this data set, it is not available for download. If you purchased a copy of this data set where your file does not match the file attributes shown above, please return the original DVD of GDS 1079b volume 3 to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1082a

Ontario Airborne Geophysical Surveys, Magnetic Gradiometer and Gamma-Ray Spectrometric Data, Grid and Profile Data (ASCII Format) and Vector Data, Smooth Rock Falls Area

Original Release Date: April 27, 2016
Notification Date of Data Errata: May 31, 2016

Errors in Geophysical Data Set 1082a, Ontario Airborne Geophysical Surveys, Magnetic Gradiometer and Gamma-Ray Spectrometric Data, Grid and Profile Data (ASCII Format) and Vector Data, Smooth Rock Falls Area (released April 27, 2016), were discovered in the data set and the digital report as outlined below.

• The latitude and longitude co-ordinates (channel names LAT_NAD83 and LON_NAD83) were incorrectly calculated for 10 flight lines comprising flight 491. The affected line numbers are 7550 to 7640. The UTM co-ordinates are unaffected. The described error is present in ASCII profile databases SRMAG.XYZ, SRSPEC.XYZ and SRSPEC256.XYZ. The latitude and longitude co-ordinates for the affected flight lines have been corrected in the profile databases.
• The description of the SRMAG.XYZ profile database channel name “height_mag” is incorrectly described in the table on page 70 of the report (section 4. DATA FILES in APPENDIX C. Archive Definitions) as “metres above terrain”. It should read “metres above sea level ”. This description has been corrected.



Corrected Files

File name	File size	Date stamp	Time stamp
SRMAG.XYZ	6,788,548,676	05/16/‎2016	4:13 PM
SRSPEC.XYZ	444,504,228	05/16/‎2016	4:17 PM
SRSPEC256.XYZ	18,986,040,708	05/17/‎2016	12:55 PM
SRMAG.XYZ.ZIP	1,533,610,407	05/18/‎2016	9:00 AM
SRSPEC.XYZ.ZIP	93,079,327	05/18/‎2016	9:06 AM
SRSPEC256.XYZ.ZIP	993,445,734	05/18/‎2016	8:46 AM

These errors have been corrected and a replacement version of this Geophysical Data Set is available. If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original DVD to Publication Sales, and a replacement copy will be sent to you free of charge. Alternatively, you may visit the GeologyOntario application to obtain the corrected version of Geophysical Data Set 1082a.

Geophysical Data Set 1082b

Ontario Airborne Geophysical Surveys, Magnetic Gradiometer and Gamma-Ray Spectrometric Data, Grid and Profile Data (Geosoft® Format) and Vector Data, Smooth Rock Falls Area

Original Release Date: April 27, 2016
Notification Date of Data Errata: May 31, 2016

Errors in Geophysical Data Set 1082b, Ontario Airborne Geophysical Surveys, Magnetic Gradiometer and Gamma-Ray Spectrometric Data, Grid and Profile Data (Geosoft® Format) and Vector Data, Smooth Rock Falls Area (released April 27, 2016), were discovered in the data set and the digital report as outlined below.

• The latitude and longitude co-ordinates (channel names LAT_NAD83 and LON_NAD83) were incorrectly calculated for 10 flight lines comprising flight 491. The affected line numbers are 7550 to 7640. The UTM co-ordinates are unaffected. The described error is present in Geosoft® binary profile databases SRMAG.GDB, SRSPEC.GDB and SRSPEC256.GDB. The latitude and longitude co-ordinates for the affected flight lines have been corrected in the profile databases.
• The description of the SRMAG.GDB profile database channel name “height_mag” is incorrectly described in the table on page 70 of the report (section 4. DATA FILES in APPENDIX C. Archive Definitions) as “metres above terrain”. It should read “metres above sea level”. This description has been corrected.
• Incorrect registration (.gi) files were supplied with the Geosoft® binary (.grd) versions of the following grids: SRGMAGGSC83.grd, SRG1VDMAGGSC83.grd, SRG2VDMAGGSC83.grd. The error resulted in the displacement of these grids from their correct positions by approximately 150 m northeast. The incorrect registration files have been replaced. This error did not affect the ASCII (.gxf) versions of these grids.



Corrected Files

File name	File size	Date stamp	Time stamp
SRGMAGGSC83.grd.gi	14,336	05/16/‎2016	11:40 AM
SRG1VDMAGGSC83.grd.gi	13,824	05/16/‎2016	11:34 AM
SRG2VDMAGGSC83.grd.gi	13,824	05/16/‎2016	11:43 AM
SRGMAGGSC83.grd.ZIP	31,539,996	05/16/‎2016	11:52 AM
SRG1VDMAGGSC83.grd.ZIP	32,064,403	05/16/‎2016	11:54 AM
SRG2VDMAGGSC83.grd.ZIP	32,261,140	05/16/‎2016	11:51 AM
SRMAG.GDB	5,289,435,136	05/16/‎2016	1:41 PM
SRSPEC.GDB	718,077,952	05/16/‎2016	4:16 PM
SRSPEC256.GDB	2,601,336,832	05/16/‎2016	4:16 PM
SRMAG.GDB.ZIP	1,934,573,519	05/18/‎2016	9:14 AM
SRSPEC.GDB.ZIP	138,927,807	05/18/‎2016	9:14 AM
SRSPEC256.GDB.ZIP	1,288,341,233	05/18/‎2016	9:17 AM

These errors have been corrected and a replacement version of this Geophysical Data Set is available. If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original DVD to Publication Sales, and a replacement copy will be sent to you free of charge. Alternatively, you may visit the GeologyOntario application to obtain the corrected version of Geophysical Data Set 1082b.

Geophysical Data Sets 1100 Series

Geophysical Data Set 1100a

Ontario airborne geophysical surveys, magnetic and electromagnetic data; grid and vector data, ASCII format, Cochrane area

Original Release Date: July 20, 2000
Notification Date of Data Errata: September 19, 2000

The following errors were found during the QA/QC process. All of these errors occurred when our subcontractor exported the data from their in-house database into the Geosoft Inc. OASIS montaj^TM format and subsequently into the ASCII format specified in the contract.

EM Anomaly Databases (thcoanomaly.csv)

1. vert_conductance channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
2. depth channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
3. line channel
   Original: line numbers were truncated to three digits (e.g., 5640 became 640)
   Revised: line numbers were replaced with the correct values

Corrected File

File Name	File Size	Date Stamp	Time Stamp
thcoanomaly.csv	4,882,223	08/30/2000	08:50a

If you have purchased a copy of this data set where your file does not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1100b

Ontario airborne geophysical surveys, magnetic and electromagnetic data; grid and vector data, Geosoft® format, Cochrane area

Original Release Date: July 20, 2000
Notification Date of Data Errata: September 19, 2000

The following errors were found during the QA/QC process. All of these errors occurred when our subcontractor exported the data from their in-house database into the Geosoft Inc. OASIS montaj^TM format and subsequently into the ASCII format specified in the contract.

EM Anomaly Databases (thcoanomaly.gdb)

1. vert_conductance channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
2. depth channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
3. line channel
   Original: line numbers were truncated to three digits (e.g., 5640 became 640)
   Revised: line numbers were replaced with the correct values

Corrected File

File Name	File Size	Date Stamp	Time Stamp
thcoanomaly.gdb	26,809,344	08/16/2000	01:41p

If you have purchased a copy of this data set where your file does not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1100c

Ontario airborne geophysical surveys, magnetic and electromagnetic data; profile data, ASCII format, Cochrane area

Original Release Date: July 20, 2000
Notification Date of Data Errata: September 19, 2000

The following errors were found during the QA/QC process. All of these errors occurred when our subcontractor exported the data from their in-house database into the Geosoft Inc. OASIS montaj^TM format and subsequently into the ASCII format specified in the contract.

EM Anomaly Databases (thcoanomaly.csv)

1. vert_conductance channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
2. depth channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
3. line channel
   Original: line numbers were truncated to three digits (e.g., 5640 became 640)
   Revised: line numbers were replaced with the correct values

Hz Profile Databases (thcochrane.xyz)

1. em_bz_drift_off (15 channel array)
   Original: certain channels contained incorrect EM data
   Revised: the 15 channel array was replaced with the correct values
2. em_bz_final_on (5 channel array)
   Original: certain channels contained incorrect EM data
   Revised: the 5 channel array was replaced with the correct values

Corrected Files

File Name	File Size	Date Stamp	Time Stamp
thcoanomaly.csv	4,882,223	08/30/2000	08:50a
thcochrane1.zip	196,853,606	08/30/2000	04:43p
thcochrane2.zip	167,860,894	08/31/2000	09:28a
thcochrane3.zip	113,401,028	08/31/2000	12:06p
thcochrane4.zip	118,513,585	08/31/2000	03:02p

If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1100d

Ontario airborne geophysical surveys, magnetic and electromagnetic data; profile data, Geosoft® format, Cochrane area

Original Release Date: July 20, 2000
Notification Date of Data Errata: September 19, 2000

The following errors were found during the QA/QC process. All of these errors occurred when our subcontractor exported the data from their in-house database into the Geosoft Inc. OASIS montaj^TM format and subsequently into the ASCII format specified in the contract.

EM Anomaly Databases (thcoanomaly.gdb)

1. vert_conductance channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
2. depth channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
3. line channel
   Original: line numbers were truncated to three digits (e.g., 5640 became 640)
   Revised: line numbers were replaced with the correct values

Hz Profile Databases (thcochrane.gdb)

1. em_bz_drift_off (15 channel array)
   Original: certain channels contained incorrect EM data
   Revised: the 15 channel array was replaced with the correct values
2. em_bz_final_on (5 channel array)
   Original: certain channels contained incorrect EM data
   Revised: the 5 channel array was replaced with the correct values

Corrected Files

File Name	File Size	Date Stamp	Time Stamp
thcoanomaly.gdb	26,809,344	08/16/2000	01:41p
thcochrane.zip	525,932,945	08/16/2000	03:55p

If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1103a

Ontario airborne geophysical surveys, magnetic and electromagnetic data; grid and vector data, ASCII format, Temagami area

Original Release Date: July 27, 2000
Notification Date of Data Errata: September 19, 2000

The following errors were found during the QA/QC process. All of these errors occurred when our subcontractor exported the data from their in-house database into the Geosoft Inc. OASIS montaj^TM format and subsequently into the ASCII format specified in the contract.

EM Anomaly Databases (thteanomaly.csv)

1. vert_conductance channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
2. depth channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
3. line channel
   Original: line numbers were truncated to three digits (e.g., 5640 became 640)
   Revised: line numbers were replaced with the correct values

Corrected File

File Name	File Size	Date Stamp	Time Stamp
thteanomaly.csv	974,505	09/01/2000	08:35a

Notification Date of Data Errata: February 5, 2002

Keating Anomalies (THTEKC27.DXF)

An error was found in this file. The Keating anomalies were plotted using the NAD83 coordinates instead of the NAD27 coordinates, so the circles plot approximately 200 m north of the actual location.

Corrected File

File Name	File Size	Date Stamp	Time Stamp
thtekc27.dxf	48,960,985	01/25/2002	11:15a

If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1103b

Ontario airborne geophysical surveys, magnetic and electromagnetic data; grid and vector data, Geosoft® format, Temagami area

Original Release Date: July 27, 2000
Notification Date of Data Errata: September 19, 2000

The following errors were found during the QA/QC process. All of these errors occurred when our subcontractor exported the data from their in-house database into the Geosoft Inc. OASIS montaj^TM format and subsequently into the ASCII format specified in the contract.

EM Anomaly Databases (thteanomaly.csv)

1. vert_conductance channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
2. depth channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
3. line channel
   Original: line numbers were truncated to three digits (e.g., 5640 became 640)
   Revised: line numbers were replaced with the correct values

Corrected File

File Name	File Size	Date Stamp	Time Stamp
thteanomaly.gdb	10,521,600	08/16/2000	01:42p

Notification Date of Data Errata: February 5, 2002

Keating Anomalies (THTEKC27.DXF)

An error was found in this file. The Keating anomalies were plotted using the NAD83 coordinates instead of the NAD27 coordinates, so the circles plot approximately 200 m north of the actual location.

Corrected File

File Name	File Size	Date Stamp	Time Stamp
thtekc27.dxf	48,960,985	01/25/2002	11:15a

If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1103c

Ontario airborne geophysical surveys, magnetic and electromagnetic data; profile data, ASCII format, Temagami area

Original Release Date: July 27, 2000
Notification Date of Data Errata: September 19, 2000

The following errors were found during the QA/QC process. All of these errors occurred when our subcontractor exported the data from their in-house database into the Geosoft Inc. OASIS montaj^TM format and subsequently into the ASCII format specified in the contract.

EM Anomaly Databases (thteanomaly.csv)

1. vert_conductance channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
2. depth channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
3. line channel
   Original: line numbers were truncated to three digits (e.g., 5640 became 640)
   Revised: line numbers were replaced with the correct values

Hz Profile Databases (thtemagami.xyz)

1. em_bz_drift_off (15 channel array)
   Original: certain channels contained incorrect EM data
   Revised: the 15 channel array was replaced with the correct values
2. em_bz_final_on (5 channel array)
   Original: certain channels contained incorrect EM data
   Revised: the 5 channel array was replaced with the correct values

Corrected Files

File Name	File Size	Date Stamp	Time Stamp
thteanomaly.csv	974,505	09/01/2000	08:35a
thtemagami.zip	295,383,447	09/01/2000	09:58a

If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1103d

Ontario airborne geophysical surveys, magnetic and electromagnetic data; profile data, Geosoft® format, Temagami area

Original Release Date: July 27, 2000
Notification Date of Data Errata: September 19, 2000

The following errors were found during the QA/QC process. All of these errors occurred when our subcontractor exported the data from their in-house database into the Geosoft Inc. OASIS montaj^TM format and subsequently into the ASCII format specified in the contract.

EM Anomaly Databases (thteanomaly.gdb)

1. vert_conductance channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
2. depth channel
   Original: anomalies that did not fit the vertical plate model were flagged with a value of -10000
   Revised: flag value replaced with a dummy value (*)
3. line channel
   Original: line numbers were truncated to three digits (e.g., 5640 became 640)
   Revised: line numbers were replaced with the correct values

Hz Profile Databases (thtemagami.gdb)

1. em_bz_drift_off (15 channel array)
   Original: certain channels contained incorrect EM data
   Revised: the 15 channel array was replaced with the correct values
2. em_bz_final_on (5 channel array)
   Original: certain channels contained incorrect EM data
   Revised: the 5 channel array was replaced with the correct values

Corrected Files

File Name	File Size	Date Stamp	Time Stamp
thteanomaly.gdb	10,521,600	08/16/2000	01:42p
thtemagami.gdb	399,549,440	08/16/2000	02:39p

If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1104d

Ontario airborne geophysical surveys, magnetic and electromagnetic data; profile data, Geosoft® format, Schreiber area

Original Release Date: August 3, 2000
Notification Date of Data Errata: January 23, 2001

An error was found when trying to uncompress THSCHREIBER1.ZIP (volume 1 of 2). This file contains the raw and filtered profile data for approximately one-half the area using Geosoft Inc. OASIS montaj^TM format, which was compressed using WinZip® 7.0.

The following error message was noted:

I/O error: unable to read from zip file
Error: invalid compressed data to inflate

Corrected File

File Name	File Size	Date Stamp	Time Stamp
thschreiber1.zip	530,398,762	07/31/2000	12:27p

If you have purchased a copy of this data set where your file does not match the file attributes shown above and the file does not uncompress properly, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1105a

Ontario airborne geophysical surveys, magnetic and electromagnetic data; grid and vector data, ASCII format, Garden-Obonga area

Original Release Date: August 31, 2000
Notification Date of Data Errata: September 29, 2000

A problem has been discovered with the NAD83 grids provided on these data sets. All 6 grid products were projected incorrectly into the NAD83 coordinate system. This affects both the binary and the ASCII grids. The proper shift between NAD27 (NTv2 datum) and NAD83 is approximately +2 m in the X direction and +220 m in the Y direction. The problem grids have a shift of +140 in the X and +500 in the Y. The original NAD27 grids are correct as are the databases.

Corrected Files

File Name	File Size	Date Stamp	Time Stamp
thgo2vd83.zip	19,365,438	09/25/2000	03:30p
thgodem83.zip	15,759,623	09/25/2000	03:31p
thgomag83.zip	18,526,717	09/25/2000	03:31p
thgoreshigh83.zip	18,056,573	09/25/2000	03:31p
thgoreslow83.zip	8,474,904	09/25/2000	03:29p
thgoresmid83.zip	17,463,631	09/25/2000	03:30p

Notification Date of Data Errata: September 29, 2000

An error was found when trying to uncompress thgopath27.zip and thgomag27_south.zip.
These files are the flight path for the entire area and the total field magnetic contours for the southern half (in UTM NAD27 projection) in AutoCAD® v13 DXF format, compressed using WinZip® 7.0.

The following error message was noted:

I/O error - unable to read from zip file
Error: invalid compressed data to inflate

Corrected Files

File Name	File Size	Date Stamp	Time Stamp
thgopath27.zip	69,203,013	08/25/2000	05:03p
thgomag27_south.zip	46,254,893	08/25/2000	04:59p

If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1105b

Ontario airborne geophysical surveys, magnetic and electromagnetic data; grid and vector data, Geosoft® format, Garden-Obonga area

Original Release Date: August 31, 2000
Notification Date of Data Errata: September 29, 2000

A problem has been discovered with the NAD83 grids provided on these data sets. All 6 grid products were projected incorrectly into the NAD83 coordinate system. This affects both the binary and the ASCII grids. The proper shift between NAD27 (NTv2 datum) and NAD83 (North American datum) is approximately +2 m in the X direction and +220 m in the Y direction. The problem grids have a shift of +140 in the X and +500 in the Y. The original NAD27 grids are correct as are the databases.

Corrected Files

File Name	File Size	Date Stamp	Time Stamp
thgo2vd83.GRD.gi	3,584	09/22/2000	02:14p
thgo2vd83.zip	15,045,403	09/25/2000	10:57a
thgodem83.GRD.gi	3,584	09/22/2000	02:12p
thgodem83.zip	13,738,096	09/25/2000	10:57a
thgomag83.GRD.gi	3,584	09/22/2000	02:11p
thgomag83.zip	14,936,911	09/25/2000	10:58a
thgoreshigh83.GRD.gi	3,584	09/22/2000	02:08p
thgoreshigh83.zip	15,090,150	09/25/2000	10:58a
thgoreslow83.GRD.gi	3,584	09/22/2000	02:02p
thgoreslow83.zip	6,767,934	09/25/2000	10:58a
thgoresmid83.GRD.gi	3,584	09/22/2000	01:16p
thgoresmid83.zip	14,227,320	09/25/2000	10:59a

If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Sets 1200 Series

Ontario Airborne Geophysical Surveys, Magnetic and Electromagnetic Data; grid and vector data, ASCII and Geosoft® formats

Original Release Date: various (see table below)
Notification Date of Data Errata: August 12, 2002

The following error was recently discovered during a detailed examination of the Operation Treasure Hunt (OTH) purchased geophysical data sets (GDS 1200 series). The original NAD27 data was improperly reprojected to NAD83. The NAD83 EASTING co-ordinates are, on average, off by approximately 5 m and theNAD83 NORTHING co-ordinates are, on average, off by approximately 241 m.

The OTH purchased data sets affected and the approximate errors in the NAD83 co-ordinate values are listed below:

Survey Area	GDS Data Set	Release Date	NAD83 EASTING error (m)	NAD83 NORTHING error (m)
Amyot-Browning	1200revised	1-Aug-01	10	243
Cobalt	1201revised	1-Aug-01	8	246
Cobalt	1201-rev1	6-Dec-02	8	246
Gowan-Evelyn	1202revised	1-Aug-01	8	246
Gowan-Evelyn	1202-rev1	6-Dec-02	8	246
Docker	1203revised	1-Aug-01	-12	236
Temagami South	1204revised	1-Aug-01	8	245
Temagami South	1204-rev1	6-Dec-02	8	245
Geco-Manitouwadge	1205	1-Aug-01	1	241
Gitche Lake	1206revised	1-Aug-01	-14	235
Hemlo	1207	1-Aug-01	1	241
Kakagi Lake	1208revised	1-Aug-01	-11	235
Albany River - James Bay	1209	1-Aug-01	2	239
Temiskaming	1210revised	1-Aug-01	8	246
Coral Rapids	1213	11-Dec-01	14	245
Kapiskau River East	1214	11-Dec-01	17	236
Kesagami Lake	1215	11-Dec-01	14	244
Melchett Lake	1216	11-Dec-01	-1	238
Natogami Lake	1217	11-Dec-01	13	244
Pakwash Lake	1218	11-Dec-01	-13	236
River Valley West	1220	11-Mar-02	16	240
Robb-Jamieson	1221	11-Mar-02	8	245
Troutlake River	1222	11-Dec-01	-17	237
Turnbull-Godfrey	1223	11-Mar-02	8	245
Turnbull-Godfrey	1223-rev	6-Dec-02	8	245

The files affected include all the NAD83 grids as well as the NAD83 co-ordinate channels in the profile, EM anomaly and Keating databases. Please note that all the NAD27 co-ordinate information is correct, including all the NAD27 grids as well as the NAD27 co-ordinate channels in the profile, EM anomaly and Keating databases.

Two possible interim solutions are available to our clients requiring the NAD83 data:

1. If you have the appropriate software, reproject the NAD27 data using Canada Mean or Manitoba-Ontario local datums (the difference between the two is a few metres, well within the surveys' margin of error).
2. If not, "move" or shift the NAD83 grids by the values listed in the above table (positive values: move grid EAST/NORTH; negative values: move grid WEST/SOUTH) or add the values in the above table to the NAD83 coordinate channels in the profile, EM anomaly and Keating databases.

The above data sets will be corrected and re-released after all the magnetic data has been leveled to the Single Master Aeromagnetic Grid for Ontario, a project presently nearing completion. When these data sets are re-released, please return the original CD to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1217-Revised: Natogami Lake Area

An error was discovered in the apparent resistivity grids for the relevelled Operation Treasure Hunt (OTH) Natogami Lake geophysical data set (Geophysical Data Set 1217-Revised) released on December 6, 2002. The error affects only the grids listed in the following table. The remaining grids as well as the profile, EM anomaly and Keating databases are correct. The apparent resistivity grid units should be in ohm-m, as indicated in the report, but are actually in log10(x) ohm-m. The following correction was applied to the apparent resistivity grids in order for the values to be in ohm-m: new grid = exp10(old grid).

Survey Area: Natogami
GDS: 1217rev
Release Date: December 6, 2002

Grid File Name	Grid File Description
thnareslow27.gxf	Resistivity, coaxial, low freq
thnareslow83.gxf	Resistivity, coaxial, low freq
thnaresmid27.gxf	Resistivity, coaxial, mid freq
thnaresmid83.gxf	Resistivity, coaxial, mid freq
thnareslow27.grd	Resistivity, coaxial, low freq
thnareslow27.grd.gi	Resistivity, coaxial, low freq, header
thnareslow83.grd	Resistivity, coaxial, low freq
thnareslow83.grd.gi	Resistivity, coaxial, low freq, header
thnaresmid27.grd	Resistivity, coaxial, mid freq
thnaresmid27.grd.gi	Resistivity, coaxial, mid freq, header
thnaresmid83.grd	Resistivity, coaxial, mid freq
thnaresmid83.grd.gi	Resistivity, coaxial, mid freq, header

Geophysical Data Set 1220-Revised: River Valley West Area

A minor error was also discovered in the survey report for the relevelled OTH River Valley West geophysical data set (Geophysical Data Set 1220-Revised) released on December 6, 2002. On page 47 (Profile Data), the units of measure for the apparent resistivity channels (ares_900, ares_7200 and ares_56000) should read ohm-metres instead of log10 ohm-metres.

Map Tile 60 000: Amyot-Browning total magnetic field and EM anomalies

The grid and EM anomalies are approximately 240 m south of their proper positions.

Map Tile 60 002: Amyot-Browning EM decay constant and EM anomalies

The grid and EM anomalies are approximately 240 m south of their proper positions.

Map Tile 60 197: River Valley West apparent resistivity and EM anomalies

The apparent resistivity grid and contour units should be in ohm-m, as indicated in the map legend, but are actually in ln(x)*3474 ohm-m.

The above data sets and map tiles have been corrected and are now available at our Publication Sales office. If you purchased any of the above data sets or map tiles, please return thEM to Publication Sales, and a replacement copy will be sent to you free of charge.

Geophysical Data Set 1248

Ontario Airborne Geophysical Surveys, Magnetic Gradiometer Data, Grid and Profile Data (ASCII and Geosoft® Formats) and Vector Data, Moosonee Area—Purchased Data

Original Release Date: June 7, 2016
Notification Date of Data Errata: July 4, 2016

Errors in Geophysical Data Set 1248, Ontario Airborne Geophysical Surveys, Magnetic Gradiometer Data, Grid and Profile Data (ASCII and Geosoft® Formats) and Vector Data, Moosonee Area—Purchased Data (released June 7, 2016), were discovered in the data set and in the digital report as outlined below.

• Three (3) files were incorrectly named in GDS 1248 and in the report (in “Appendix E. GeoTIFF and Vector Archive Definition” (p.23)). The following file names have been corrected.
  

  Old File Name	Corrected File Name
  “GeoTIFF Images”
  MO2VD83.TIF	MOG2VDMAGGSC83.TIF
  MOMAG83.TIF	MOGMAGGSC83.TIF
  “GeoTIFF Images”
  MOMAG83.DXF	MOGMAGGSC83.DXF

• For Block 4 (“Block B Discovery East”), data in the final longitudinal and lateral gradients channels (channel names MAG_GRAD_LAT_FINAL and MAG_GRAD_LONG_FINAL) were switched. The affected flight-line numbers are L9010 to L10030. The described error is present in ASCII profile database MOOSONEE.XYZ and in Geosoft® binary profile database MOOSONEE.GDB. The final longitudinal and lateral gradients data for the affected flight lines have been corrected in the profile databases
  • All Geosoft® binary (.grd) and ASCII (.gxf) versions of the grids have been updated.
  • The GeoTIFF (.tif) files have been corrected.
  • The Keating correlation coefficients profile databases for both Geosoft® binary (.gdb) and ASCII (.csv) versions have been updated.
  • Among vector files, the Keating correlation coefficients and residual magnetic contour lines have been corrected.
• An incorrect channel was used to create residual of the total magnetic field (MOMAG83) grids. Both Geosoft® binary (.grd) and ASCII (.gxf) versions of the grid have been updated with the correct channel.
  

  Corrected Files

  File name	File size	Date stamp	Time stamp
  MOOSONEE.XYZ.ZIP	363,590,697	06/22/2016	02:33p
  MOOSONEE.GDB	1,292,041,216	06/20/2016	01:41p
  MOG2VDMAGGSC83.gxf	102,371,381	06/15/2016	05:01p
  MOGMAGGSC83.gxf	84,566,534	06/15/2016	05:02p
  MOLAG83.gxf	92,962,627	06/15/2016	05:04p
  MOLOG83.gxf	93,105,398	06/15/2016	05:05p
  MOMAG83.gxf	88,012,760	06/22/2016	11:33a
  MOG2VDMAGGSC83.grd	45,801,692	06/20/2016	10:09a
  MOGMAGGSC83.grd	45,801,692	06/22/2016	11:42a
  MOLAG83.grd	45,989,492	06/20/2016	04:14p
  MOLOG83.grd	45,989,492	06/20/2016	04:14p
  MOMAG83.grd	47,413,416	06/22/2016	11:42a
  MOG2VDMAGGSC83.tif	286,477,749	06/15/2016	04:57p
  MOGMAGGSC83.tif	286,748,093	06/15/2016	04:58p
  MOKC.csv	253,604	06/15/2016	05:05p
  MOKC.gdb	292,864	06/20/2016	03:14p
  MOGMAGGSC83.dxf	42,652,449	06/15/2016	01:10p
  MOKC83.dxf	12,425,933	06/15/2016	01:10p

These errors have been corrected and a replacement version of this Geophysical Data Set is available. If you have purchased a copy of this data set where your files do not match the file attributes shown above, please return the original DVD to Publication Sales, and a replacement copy will be sent to you free of charge. Alternatively, you may visit the GeologyOntario application to obtain the corrected version of Geophysical Data Set 1248.

We regret any inconvenience these errors may have caused.