Changing axis limits
The plot's axis limits may be changed using the following three
buttons.
Zoom in. When this button is activated you may
zoom in to a rectangular region of interest by clicking and dragging on the plot.
Zoom out. Click this button to zoom the plot
back out to the default limits (based on the data range).
Change axis parameters. Click this button to launch a dialog box
allowing you to enter numeric values for the axis limits and tick intervals
along each axis.
Modifying the plot
The plot legend includes checkboxes for toggling the display of the
different plot groups. Click in a box to remove the corresponding group from
the plot and click it again to re-display that group.
The Edit menu contains items for modifying the main plot title
axis titles and for showing and hiding the stratigraphic event labels, which are
short character strings read from the stratigraphic
event data file. Generally, event labels will overlap unless the density
of data in the plot window is fairly low. Lower data densities can be achieved by
toggling plot groups off or by zooming in to a more detailed view.
Saving the plot
Select Save plot... from the File menu to save the current
plot to a file. The current format options for the output file are SVG (Scalable
Vector Graphics), PNG, and JPEG. The latter two options use Java's Robot and
ImageIO packages to generate an automatic screen capture of the plot region and
write the image to a file. Thus, the output file will contain a raster image
of plot region as you see it on the screen. SVG is an XML specification for
describing vector graphics and the output SVG file (a plain text file) is designed
for convenient editing of various plot characteristics, with font and line
characteristics for various plot elements and the palette of plotting symbols
defined at the top of the file.
Saving data
Use the Save projected data... item on the File menu to
write out a file containing the stratigraphic event data projected to the LOC.
You will be asked to enter your name or initials and then a
header line comment, both of which will be written to the output file. Then you
will be presented with a standard dialog box for specifying the location and
name of the output file.
The projection consists of replacing the input age value(s) for
each event with the ages on the LOC corresponding to the minimum and maximum
depth for that event. The data file will be written in the same format as an
input stratigraphic data file, meaning you can read the projected data back in
and diplay them. All the depths in the output file will be in mbsf, so you do
not need a core-depth data file to interpret a projected stratigraphic event
data file.
Use the Save LOC... item to write out the current LOC data to a
file. In this case you only get the "save file" dialog box. The first line of
the LOC file will contain the hole id and the current date.
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Reading line-of-correlation (LOC) data
Whenever you read in new stratigraphic event data, ADP automatically
calculates a line-of-correlation (LOC) consisting of a single straight segment
connecting the extreme age and depth values in the dataset. At this point you
may either use the palette of buttons to modify the LOC or read in a previously
existing LOC from a LOC data
file. To do the
latter, select Read LOC... from the File menu and using the
resulting dialog box to navigate to and open the desired LOC data file.
Once the file is read, the program will display the LOC on the plot and
will also display the opening comment line from the LOC file after the LOC
file info label.
Modifying the line-of-correlation
The LOC is represented on the plot as a green line, with open green
squares representing the control points for the line. You may move, add, or
delete points using the first three buttons in the palette at the left. (Let
the mouse hover briefly over a button to see a brief description of its
function.) The buttons work as follows:
Move a control point. When this button is activated you
may use the mouse to grab and drag an existing control point to a new location
(click on the point, drag, release). Use the age-depth coordinate label at the
bottom of the plot to keep track of the mouse location. Once you grab a point, the program
displays light gray lines delimiting the boundaries for a legal move for that
point. These boundaries prevent you from creating an age model where age decreases
with increasing depth. You may, however, create a hiatus by dragging the mouse
beyond the upper or lower bounding line. In this case, the control point will stick
at the boundary and will be assigned the bounding depth.
Add a control point. When this button is activated you may
add a control point with a single click on the plot. Light gray lines delimit
the legal locations for control point additions, again allowing only
non-decreasing age with increasing depth.
Delete a control point. When this button is activated you may
delete a control point by clicking on it.
Reading stratigraphic data from the Neptune database
To retrieve data from the Neptune database, select Get Neptune Data...
from the File menu. Momentarily, you should be presented with a world map
showing locations of DSDP and ODP holes represented in the database. Initially,
the hole selection tool (pointer) is activated. While this button is activated,
you can click on the map to select holes near the cursor location. The information
for the selected holes will appear in the data table at the bottom. To retrieve
the data for one of these holes, select the appropriate row in the table with
a single click on any cell in that row and then click Retrieve Selected Data.
A text window will then appear, displaying the stratigraphic event data as they
are retrieved from the database. Once the all the events for the hole are found,
the title of the text window changes from Retrieving Neptune data... to
Neptune data retrieved and the plot is made. You can get the data window
out of the way either by closing it (click on the x in the corner) or
repositioning it or by clicking on the main application (plot) window to bring
it to the front. Later, you can re-display the data window
by selecting Show Data Window from the Edit menu.
The data window displays data as tab-delimited fields, in the same format
as a local stratigraphic
event file. On most
systems you should be able to select and copy the data and then paste them into
a text editor to create a local file. A right-click (Windows) or ctrl-click (Mac)
on the text area should bring up an editing pop-up menu.
In the map window, choose the Zoom in button (magnifying glass with "+")
and then drag a rectangle on the map and release to zoom in to that region. Then
click on the pointer button to return to hole-selection mode. The
Zoom out button (magnifying glass with "-") will automatically zoom back
out to global extent, leaving the current mode (selection or zoom-in) unchanged.
For any zooming operation, there will be a bit of a pause while the code
retrieves a new world relief image at the appropriate scale.
The code will also attempt to retrieve an age model from the Neptune
database and display it, along with information regarding the age model
quality and the date it was developed (in the LOC file info line at the
top of the application). If it cannot find an age model for the selected hole,
it will generate the default straight-line LOC connecting the extreme depth
and age values.
Reading stratigraphic data from local files
To read data from local files, select Read data... from the File menu
to initiate data input. You will then be presented with two dialog boxes in
succession, the first asking you to locate and open a
core-depth data
file and the second asking you to
locate and open a stratigraphic event data
file. The captions at the top of each dialog box indicate what they are
asking for, but you have to pay close attention to notice them.
All ADP data files are plain text files, but the program enforces no
file-naming conventions. Use names that help you remember what is in each file.
The information in the core-depth data file is used to interpret any
stratigraphic event depths that are in core-section,cm format in the
stratigraphic event data file. However, the core-depth data are not required to
interpret stratigraphic event depths that are already presented in meters below
sea floor (mbsf). You may skip input of core-depth data by clicking
Cancel on the first dialog box. In this case, the program will still
present you with the stratigraphic event data file dialog box and will still
read and plot events with depths in mbsf.
As the stratigraphic event file is processed, the data window will show
the resulting data values, with the depths in mbsf (rather than core-section,cm
format). Once the data have been
processed, the plot will update. Again, you can either close the data window or
simply switch to the main application (plot) window by clicking on it. The
opening comment lines from both the core-depth and
stratigraphic data files are displayed at the top of the application. You
should check these to make sure that you have read the files you intended to
read.
References
D. Lazarus, 1992, Age Depth Plot and Age Maker: Age Modeling
of Stratigraphic Sections on the Macintosh Series of Computers, Geobyte,
February 1992, pages 7-13.
D. Lazarus, 1995, User's Guide to Age-Depth Plot and Age Maker,
Version 2.08, August 15, 1995 (unpublished report).
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