1. Finding suitable papers
2. Preparing NAVDAT RockChart file
3. Location information
4. Handling age data
5. Geochemistry and Isotopic Data
6. Sample descriptions, Location quad, Rock Class, State
and the rest
7. Submission
NAVDAT (from the NAVDAT homepage):
The NAVDAT project is compiling existing age, chemical, and isotopic data from Late Cretaceous to Holocene extrusive and intrusive igneous rocks from the western United States, British Columbia, and northern Mexico into a web-accessible electronic database. NAVDAT will be integrated into a geographic information system (GIS) to allow visualization of complex age-compositional patterns in volcanism throughout the study region. The addition of necessary relational and graphical tools will allow users of the database to address a wide variety of issues concerning the geologic evolution and present volcanic state of western North America.
The most efficient and error-proof method of compiling data is by using RockChart, a custom-made spreadsheet program designed specifically for the NAVDAT project.
Any paper entered into NAVDAT
needs to have two things included: location and age data. Most papers
will have some geochemistry and isotope information, but location and
age data are required, even if the paper only lists a general geologic
age and/or a general area for location. The paper will not process in
the submission to NAVDAT if these two data fields are not filled.
To begin searching for suitable papers for entry into the database, GeoRef
is an excellent search tool. GeoRef is a database of most major geological
articles that have been published.
To reach the GeoRef site:
Go to here.
-or-
1. Go to http://www.lib.unc.edu (UNC’s
library site)
2. Under “Articles & More”, click “Article Databases & More”
3. Search for “GeoRef” and the GeoRef site should be found.
These will probably be slightly different to suit your organization/school's
article database.
Once at the GeoRef site, make sure to search both database (GeoRef and GeoRef in Process) by clicking the checkboxes on the main section.
Under the search section, enter in suitable search terms such as “u-pb”, “ages”, “k-ar”, “Cretaceous”, “California”,
etc. depending on what type of paper is needed. Make sure. Make sure that you
are searching for your terms “anywhere” in the paper, and you are
searching for “all of the words.” This will help slim down the
search results, while still providing the broadest range of matching papers.
After the search results come up, scan the titles for appropriate papers. These
will usually include something about the aging or geochemistry work done.
After selecting a possible entry candidate, click on that paper. At the
paper’s metadata screen on the very bottom will be an accession number.
This number uniquely identifies each paper in the GeoRef database and NAVDAT
follows this lead and uses it to identify each paper entered.
Once the accession number is found, the compiler must check to see if the paper
has been entered into NAVDAT previously. The method for searching the NAVDAT
database for papers by GeoRef follows:
1. Go to http://navdat.geongrid.org.
2. Click on “Enter the Database” in the top-left corner.
3. On the next screen, under “reference parameters” select GeoRef,
then “continue.”
4. Then, enter in the accession number for the possible paper.
5. If no search results come up, the paper has not been entered and can be
proceeded with.
Now, you should download the paper's metadata and save it to your hard drive. Most article databases provide a text file download of the the metadata. Make sure the full info is downloaded as the accession number is often left out of the short versions of the paper's metadata. A sample metadata file is found here.
Once the metadata is downloaded, open RockChart and go to Paper->Add Metadata... and select the text file of the metadata that you downloaded and click OK. You should get a confirmation box saying the metadata adding went well.
RockChart can also check for existing papers for you. Once metadata is added, go to Paper->Check for existing paper... and a box will appear telling you whether or not you should proceed with the paper.
Go to the library and find the print copy of the article. Photocopy the article, as all papers entered into NAVDAT will be filed away after completion.
2. Starting the NAVDAT RockChart file
You should be looking at a
blank spreadsheet, with only one column present: the sample name column.
The wisest thing to do to avoid confusion later is to enter in the names of
the samples first thing, one per line. Once all the sample names are entered,
the paper's data should be added.
Adding columns is a very straight-forward process. Under the 'Columns' heading on the top menubar, you will see 'New Column...' and several options of different columns that can be added. Under each dialog box, drop down menus will be present that will provide different options of methods, institutions, and other column specific information. The information that is selected should be match the information that is given the full body text of the paper. Once the column is added the data from the paper can be added for that column.
Location information must be
included in any NAVDAT file. RockChart currently offers two formats for
location data, decimal degrees and degrees-minutes-seconds. Location
columns can be added from Columns->New Column...->Location dialog.
Precision must be included in the corresponding location precision column beside the latitude and longitude columns. The table belows give the precision values.
Known
to the nearest...
|
Precision
Value
|
100 km
|
1
|
10 km
|
0.1
|
1 km
|
0.01
|
100 m
|
0.001
|
10 m
|
0.0001
|
This is taken given that 100km is approximately 1 degree.
a. Gathering location from plotted points on a map
Often a paper will not have accompanying latitude/longitude but will just include a map with the points plotted on them. To handle this, the maps are scanned in digitally and then ArcMap is used to georeference them.
First the map must be scanned in using any of flatbed scanner. Open the new picture file in ArcMap.
The UTM zone of the map must be correctly set before the map can be georeferenced. To find which UTM zone to use, go here. Then click in the main window of ArcMap and select "properties." Select the "Coordinate System" tab. Under the "Predefined" folder, go to "Projected Coordinate Systems", then "Utm", then "Nad 1927" if the map is older or "Nad 1983" if the map is recent. The papers should specify which type of map they are using. Then under that folder, select the appropriate zone.
Now the map needs to be georeferenced. If the map is not visible, select it on the left hand side and select "Zoom to layer". This can be used anytime the map gets out of the field of sight.
If the map is in UTM already, the UTM coordinates can be directly entered for georeferencing.
If the map is listed in degrees or anything else, these will needed to be converted to UTM. This is a very handy tool for that. (If used, make sure you select the correct UTM zone and whether it NAD 1927 or NAD 1983.)
In ArcMap, if the georeferencing toolbar is not visible, go to "View", then "Toolbars", then "Georeferencing." On your map, right click on a place where the latitude and longitude is known (such as a the crossing of a grid line) and click "Enter x y." Enter in the x and y boxes the converted value you got from the web converter. Your map will be probably disappear from field of view. Just do as stated above, and zoom back to layer. Find 3 or 4 points to georeference on the map and convert them as needed them and georeference them as the same. The more points that is done, the more accurate the location data will be. When done with all the points, on the tool bar, click "Georeferencing" and select "Update Georeferencing".
Now, the location for the plotted sample points must be found. Right click in the main window of ArcMap and select the "General" tab. Beside the "Map" field select "Degrees minutes seconds". (Note: Yes, in NAVDAT, decimal degrees is entered in, but in ArcMap the decimal degrees precision only goes to two decimal places, so therefore degrees, minutes, seconds is more precise and must be used and then converted.)
Now on the map, you can mouse over the plotted points and in the bottom right hand corner of ArcMap, the latitude/longitude will be shown. Enter this location data in RockChart in the correct place.
b. Township/Range/Section
Coming soon.
Age columns are added by going to Columns->New Column...->Age. In this dialog box, there are three main things that will need to be selected. The first is the method of the age calculations, the second is the mineral on which the tests were done, and the third thing is the institution at which the tests were completed. Unknown is an option for each field, in case it the paper is missing this information.
Also there are tick boxes for maximum and minimum age. If maximum and/or minimum ages are included with the average age in the paper (this includes the age listed as having an error), these boxes will remained ticked.
5. Geochemistry and Isotopic Data
If a paper has included geochemistry and/or isotopic data (most of them do) this should be entered). As with the age and location sections, the method must be selected.
6. Sample descriptions, Location quad, Rock Class, State and the rest
The remaining fields are mainly supporting information.
In sample descriptions, if the sample is described in detail, enter that here.
The name of the quadrangle goes underneath the location quad heading.
Enter in the rock class if it is listed. This will often be found in the sample description.
After the file has been completed, it must then be compiled. This is done under Paper->Compile Paper... It must be saved with the properly formatted filename. This format is DDDD-DDDDDD_Last.xls where D’s stand for the Georef number and Last is the last name of the first author. Do not forget the dividing underscore. If the metadata has been properly added it should be like this automatically.
Login to the NAVDAT with your username and click the “Upload Data” tab. Use the Browse button to select your finished file (the .txt file) and then click upload. The file then will be checked by the NAVDAT folk to insure its correctness as far as formatting and documentation goes. If they have any problem, they will e-mail you and let you know what to fix.
And then you're done!!