Canadian Database of Geochemical Surveys

KML Maps Help Topics

Overview

This website includes a very large number of downloadable KML files. KML (keyhole markup language) is an international standard for displaying geographic data, and KML files can be viewed by many different software packages, including several that are freely available. The KML files on this website have all been tested with Google Earth™, a freely available internet Earth browser. All of the descriptions below apply to Google Earth™ and it is assumed that Google Earth™ is installed on the user's computer. Some content in the KML files may display differently in other software.

There are a few different categories of KML files available on this website, each of which has some unique characteristics which are not always immediately apparent. The following four sections describe the categories and explain their characteristics in more detail.

Index Maps of Geochemical Surveys

Two general index maps for geochemical surveys are available:

All Surveys: When the link is clicked, Google Earth™ displays the All Surveys index map showing the geographic extent of every survey (over 1,200) in the catalogue.
Raw Data Surveys: When the link is clicked, Google Earth™ displays the Raw Data Surveys index map showing the geographic extent of only those surveys for which raw data have been loaded into the database (less than 10% of the total).

These two index maps have the same characteristics. Each survey is represented by:

a rectangular bounding box defined by the minimum and maximum latitude and longitude of the survey's extent;
a polygon within the bounding box, which more closely constrains the extent of the sample sites. Sometimes the sites are defined by a polygon that exactly matches the bounding box and in this case, only one outline will be visible.
a yellow star, which denotes the centroid of the survey and represents the geographic centre of each polygon. Clicking on the star displays a balloon that lists the title of the survey and provides a hyperlink to the full metadata page for that survey.

Some surveys are represented by more than one polygon/star. Geochemical surveys often sample irregular and discontinuous areas, and representing their extent with a single polygon would be very misleading. Regardless of the number of polygons that represent the sampling area of the survey, each survey has only one bounding box enclosing the polygon or polygons.

The "Temporary Places" legend to the left of the map categorises the surveys by groups, according to the kind of material sampled (e.g. vegetation, NGR lake) or by some other criteria (e.g. indicator minerals, resource assessment). The number of surveys that fall into each category is listed after the survey group. By default, all surveys in all categories are shown when the index maps are first displayed but the user can opt to display only those surveys belonging to a particular category. For example, by clicking on the radio button beside till, only those surveys where till was sampled will be displayed. Note that some surveys fall into two or more categories and will be displayed when the radio button beside any of its associated survey groups is clicked.

Index Maps of Analysed Elements

Index maps of analysed elements are available from the periodic table . One KML index map is available for each element analysed, and each index map displays the surveys that have raw data available in the standardised CDoGS format for that element. The index maps are available by clicking on the red cells of the periodic table.

As an example, here is a link to the index map of sodium (Na) analyses. Surveys are delineated in the same way as in the "All Surveys" and "Raw Data Surveys" index maps (bounding boxes, polygons and stars) described above, and can be selected using the legend in the same way by selecting a survey group category (e.g. soil) to view. However, clicking on the yellow star will display a balloon with a different set of information, focussing on the details of the element's analysis. Frequently, there are several sets of analyses for a single element, corresponding to different field samples, preparation lab samples or analytical techniques. A table listing details about each dataset is provided in the pop-up balloon. The element name and the number of datasets available is given above the table. The following information is provided in the table, in the order the columns are arranged:

N: The number of samples in the dataset.
Sample Type: The sample medium e.g. till, soil, vegetation.
Preparation: The size fraction that was prepared from the sample and analysed.
Decomposition: How the sample was dissolved prior to analysis, if applicable.
Technique: The method used to geochemically analyse the samples.
Analytical Metadata: A link to details about the analytical history of the dataset, including specifics of the analysis, the elements analysed and the laboratory that carried out the analysis.
Map: A link that displays a KML map of the geochemical distribution of that element in Google Earth™, assuming it is installed on the user's computer. Additional help for using these maps is available below.

The pop-up box also has a link to the corresponding Survey metadata page which provides more detailed information about the survey. A description of the content on the Survey metadata page can be found under the Help topic Surveys.

Analytical Data Maps

Analytical data maps have been generated for the surveys that have raw data available for download in the standardised CDoGS format. These data maps can be viewed in Google Earth™ from two places on this website:

From the Index Map of Analysed Elements launched by clicking on an element in a red box on the periodic table (see description above);
From the KML link in the last column of the Analytical Methods table. Details can be found here.

The KML maps of each analysed quantity can be viewed based on survey, material analysed, preparation lab material and analytical method. These parameters are listed in the table in the balloon that pops up when clicking on a yellow star on the Index Map of Analysed Elements as well as in the Analytical Suites and Analytical Methods tables if viewing the maps from the Analytical History section of the Extended Metadata Subsection. The user can select a map based on these parameters.

As an example, here is a link to a map of arsenic (As) data for the < 63 micron size fraction of till samples, analysed by INAA, for a survey carried out in the Baker Lake area of Nunavut in the 1970s.

Features of the KML map

Survey Limits

When the KML map displays, the survey extent is shown by a purple rectangle called a bounding box, which represents the minimum and maximum latitude and longitude. A shaded polygon that more closely constrains the extent of the sample sites is also shown in purple. This polygon may or may not be the same shape as the bounding box. For the Baker Lake arsenic survey, this polygon is the same size and shape as the bounding box.

Survey Centroid

The centroid, or geographic centre, of the survey is indicated by a yellow star . If the survey is represented by more than one polygon, each polygon will have its own centroid. The survey's unique identifier, known as the Survey Key, is displayed beside the star. For the Baker Lake survey, the Survey Key = 210027. Clicking on the centroid star displays a balloon with a title for the survey and provides a hyperlink to the full metadata page for that survey.

Analytical Data

The location of each sample site is represented by a coloured cross, which provides information about the analytical data for the selected element, arsenic in this example. The crosses are coloured according to the quartile values for the dataset, as shown below:

Colour of Cross		Quartile Range
blue		0 - 25 ^th
green		25 - 50 ^th
yellow		50 - 75 ^th
red		75 - 100 ^th
grey		missing data

Hovering over the crosses on the map with the mouse displays the arsenic analytical value for the sample at that site. Clicking on a cross displays a balloon with the value of arsenic at the site, the latitude and longitude of the site, as well as the Lab Key, Survey Key and Field Key which help relate the sample to the MS-Excel files described here.

These crosses can be toggled on and off as can the actual analytical values at each site. This will be described more fully in the Map Legend section immediately below.

Map Legend

As previously noted, the information in this section is specific to Google Earth™. Other KML viewers may display map legends differently, or not at all.

On the left-hand side of the screen, under My Places, there is a section called Temporary Places. This is where information related to the KML map is found. This legend allows layers on the KML map to be toggled on or off. The legend is hierarchical and will be explained for the Baker Lake arsenic map for Survey Key=210027.

Under Temporary Places, there is a blue hyperlink labelled 'Analytical data'. This refers to the file that contains all of the layers related to the analytical data presented on the map. Clicking on 'Analytical data' displays a pop-up balloon that lists the quantity being displayed on the map and its units (for Baker Lake it is 'As ppm'), the sample type (till <63 micron), the decomposition (none) and the analytical technique (INAA). Beneath this information there are hyperlinks to the Survey Metadata page and the Analytical Metadata page for the samples.

When the “+” symbol beside 'Analytical data' is expanded, a hyperlink for the survey (or surveys) whose samples have been analysed and displayed on the map is shown. In this example, the samples are from Survey 210027, till from the Baker Lake area. This means that samples from only one survey were bundled together and sent to the analytical lab.

When the 'Survey' hyperlink is clicked on the legend, a pop-up balloon is displayed that shows the title of the survey and provides a link to its Survey Metadata page. When Survey 210027 is expanded, by again clicking on the “+” symbol, three items are shown:

Extent

Unchecking the box beside Extent toggles off both the bounding box and polygon outline at the same time. If the Extent section is expanded by clicking on the '+' symbol, a check box for polygons and one for bounding box are displayed. When “Extent” is toggled off, the polygon that more closely constrains the extent of the sample sites disappears from the map. When “Bounding box” is toggled off, the rectangle that defines the minimum and maximum latitude and longitude disappears from the map.

Yellow star icon

The survey Key beside the star icon is a hyperlink that when clicked, displays the title of the survey and provides a link to its Survey Metadata page in a pop-up balloon on the map. Clearing the check box beside the star toggles the centroid star and the Survey Key label off so they are no longer visible on the map.

Analytical values

The quantity analysed (As, in the Baker Lake example) and the number of sites (n=1929 for Baker Lake) are listed. If the box beside the element name is toggled off, the coloured crosses representing sample sites and the arsenic data disappear.

If this section is expanded by clicking on the '+' symbol, two entries are displayed beneath it: 'symbols only' and 'symbols plus values'. 'Symbols only' displays just the sample location crosses coloured by quartile values of the arsenic dataset. By default, this is toggled on when the map is first loaded. The second entry, 'symbols plus values', when toggled on, will display the actual As value at each site beside the coloured crosses. With this view toggled on, the map can become cluttered, depending on the zoom level. Therefore, by default, this entry is toggled off when the map is first loaded.

When the 'symbols only' section is expanded by clicking the '+' symbol, a list of arsenic values classified into percentile ranges is displayed. Although the crosses are coloured according to quartiles, the data shown in the legend have been divided into 20 percentile groups (0-5 ^th, 5-10 ^th, 10-15 ^th etc.). Each of the four quartile ranges covers five of these percentile groups. For surveys that have samples with missing data, there is a category for missing data at the top of the list.3160; None of the Baker Lake samples are missing arsenic data. Sites with missing data are indicated by a grey cross on the map and there are none on the Baker Lake till map.

This expanded section also displays the arsenic values for each range as well as the number of samples that fall into that range. In the Baker Lake example, the first line of the 'symbols only' section says "1.5-3.4 (0-5; n=89)". This indicates that there are 89 samples that fall into the 0-5 ^th percentile range which includes arsenic values from 1.5-3.4 ppm.3160; Even though there are five categories representing the 0-25 ^th quartile range, all of the samples that fall in these categories are coloured blue on the map. The samples that fall into the five categories representing the 25 ^th -50 ^th quartile range, are all coloured green; the samples that fall into the five categories representing the 50 ^th -75 ^th quartile range, are all coloured yellow; and, the samples that fall into the five categories representing the 75 ^th – 100 ^th quartile range are all coloured red.

The coloured crosses can be turned off by toggling off the box beside the categories. For example, if the user was interested in the location of samples where As values are above the 75 ^th percentile, all other categories can be turned off, displaying only the red crosses.

Each percentile category can be expanded by clicking on the “+” symbol beside it. Each sample in the category will have an entry. For example, if the 10-15 ^th percentile section is expanded, labelled “6.4-6.7 (50-55; n=125)" on the legend, each of the n=125 arsenic values in that category will be listed as hyperlinks. These individual samples can then be toggled on or off by checking or unchecking the box beside it. If the hyperlink of the actual As value for a sample is clicked, a balloon will appear on the map giving details about that sample, including As value and units, latitude and longitude of the sample site, as well as the Lab Key, Survey Key and Field Key which help relate the sample to the MS-Excel files described here.

When the 'symbols plus values' section is toggled on (it is off by default when the map is first displayed), the analytical values at each site are displayed on the map in addition to the location crosses coloured by quartile. Depending on the zoom factor, the map may appear cluttered. Using the zoom feature in the top right hand corner of Google Earth™ (the plus sign), allows the user to see a more detailed view of the sites.

When the 'symbols plus values' section is expanded by clicking on the "+" sign, the same list of analytical values (arsenic for the Baker Lake example) broken down into the percentile ranges described above for 'symbols only' is shown. Sometimes two or more values are shown at the same site. This means that multiple analyses were done on the same sample, or that two or more samples were collected at the same site and each has a value. In this case, the two crosses would overprint as they are at exactly the same location and appear as a single cross.

Analytical Data Maps - special case

The analytical data map for arsenic in till from Baker Lake displayed samples from only one survey on the map. Sometimes the Analytical Sample Bundle the user chooses to display on a map, contains samples from more than one survey. The analytical data maps for a till survey in the central Miramichi, New Brunswick do show samples from more than one survey on the map. This special case is best explained by using an example.

To illustrate this, close Google Earth™ (without saving) if it is open. Go to the Extended Metadata section for Survey 210038 ( shortcut). Open the Analytical History section by clicking on the arrow beside the section title. The Analytical Sample Bundle table showing seven sample bundles (a bundle refers to a group of samples sent to a lab) is displayed. Choose Index 5 by clicking on the Details box in the first column of row 5 ("Serpentine Lake (21O/2), New Brunswick till samples (Doiron – GSC Quebec) - INRS XRF + INA analyses").

This opens a second table, the Analytical Suites table. It is nested within the Analytical Sample Bundle table under the row that was expanded. Next, expand the Details for Index = 1 (Suite = INRS XRF (1)) of this second table by clicking on the Details box in row 1. This opens a third table, the Analytical Methods table, which is nested within the second table under the row that was expanded. From this third table, select the KML map for barium (Ba) by clicking on the link in last column of the first row (Index = 1). The Ba map will display in Google Earth™.

To summarise, barium was selected from analytical sample bundle “Serpentine Lake (21O/2), New Brunswick till samples (Doiron – GSC Quebec) - INRS XRF + INA analyses”. This bundle was sent for X-ray fluorescence (XRF) analyses carried out by the INRS lab in Quebec for samples in Survey 210038 that was carried out by the GSC – Northern Canada Division.

On the Google Earth™ map, the survey centroid, the bounding box and the polygon that more closely constrains the samples for survey 210038 are all visible. Notice that the crosses representing the sample locations and analytical data for Ba are not scattered throughout the extent of Survey 210038 but are clustered in a box that has a centroid labelled Survey 050004, a survey carried out by the Quebec office of the Geological Survey of Canada. This is because the analytical sample bundle that was chosen contains samples from both Survey 210038 and Survey 050004. The location of Survey 050004 overlaps with the area covered by Survey 210038 and samples that were originally collected by the Northern Canada Division in GSC Quebec's new survey area were reanalysed by GSC Quebec with new samples they collected in Survey 050004. As a result, data from the two surveys are contained in a single analytical sample bundle.

Although the original starting point was the metadata for Survey 210038, the only samples from that survey that occur in the chosen analytical sample bundle are those that were reanalysed along with new samples from Survey 050004. Therefore, this analytical sample bundle is also listed in the Analytical History section of the Survey Metadata page for Survey 050004.

The legend on the left-hand side of Google Earth™ contains the same features as described for the arsenic map for Baker Lake, Survey 210027. The difference is that when the Analytical data section is expanded, there are two surveys listed: 210038 and 050004, indicating that samples from both of these surveys are included in the analytical sample bundle. Each of these surveys can again be expanded, showing the three categories described above: Extent, Yellow star icon for the survey and Analytical values. These can be toggled on and off depending on what layers the user wants to display on the map.

The Analytical values section for Survey 210038 (labelled Ba; n=93) indicates that 93 samples from this survey are included on the map. The Analytical values section for Survey 050004 (labelled Ba; n=247) indicates that 247 samples from this survey are included on the map.

As with the Baker Lake arsenic example above, the sample locations for each survey can be displayed with or without the Ba values. The default is to have only the coloured crosses appear when the map is first opened. The “Symbols plus value” box can be toggled on if the user would like to see the barium value displayed beside each sample location. Once again, the crosses are coloured with respect to their quartile ranges, as described above.

When any of the items below Analytical values is expanded by clicking the “+” symbol, a list of the barium values classified into percentile ranges is displayed, as explained above for arsenic. These ranges can be toggled on or off to see only certain ranges or to see the distribution of samples from just one survey. For example, if all of the analytical values for Survey 050004 are toggled off, only samples from Survey 210038 will remain visible on the map.

Index Maps of NTS Topographic Map Sheets

Three index maps for NTS topographic map sheets are available:

NTS 1m Index
NTS 250k Index
NTS 50k Index

When any of the NTS Index links is clicked, a KML index map of the NTS sheets available for Canada is displayed in Google Earth™. The index map may take a few moments to load and appears as an overlay grid on the map of Canada, showing all of the 1:1m (or 1:250k or 1:50K) map sheets for the country, depending on what scale is chosen. For all of the map scales provided, clicking on the small square at the centre of a map sheet on the overlay grid displays a pop-up balloon with metadata for the map sheet, a link to more detailed metadata in GEOSCAN, as well as a link to download the NTS sheet as a PDF from GEOSCAN.

Other KML Maps

Census Geography Maps

Statistics Canada defines and uses geographic units to classify its census data. The classification consists of four main levels: geographical regions of Canada (Atlantic, Quebec, Ontario, Prairies, British Columbia, Territories), provinces and territories, census divisions (such as counties and regional municipalities) and census subdivisions (such as municipalities). The four geographic levels are hierarchically related.

Index maps showing Statistics Canada's standard geographical boundaries (provinces and territories, census subdivisions and census subdivisions) for the 2006 and 2011 censuses are available as KML files. GML data files for the geographical boundaries were obtained from Statistics Canada, and reformatted for this web site.

Provincial and Territorial Boundaries: The KML map presents polygon outlines of the provinces and territories as defined by Statistics Canada.
Census Division Boundaries: Canada's provinces and territories are further divided into census division boundaries by Statistics Canada. These polygons are presented on the KML map.
Census Subdivision Centres: Census divisions are subdivided into census subdivisions, of which there are several thousand. The KML map presents the (approximate) centre of each subdivision as point data.
Census Subdivision Boundaries: The KML map presents, as polygons, subdivision boundaries. Note: this file is very large and may take some time to download and display.

Canadian Geopolitical Boundaries

The Canadian geopolitical boundaries were obtained from Geobase and reformatted for this web site.

The KML map displays the international boundary, inter-provincial/territorial boundaries and the boundaries of Canada's exclusive economic zone. The EEZ is an area of the sea extending out to 200 nautical miles from the baseline (low-water line along the coast).

Note that the Nunavut-Northwest Territories boundary is correct and differs from other published sources (Google™, Statistics Canada provincial and territorial boundaries, 2006 and 2011 census geography).