GeoMapApp© Help
Drilling-DSDP/ODP/BRG
When you select this menu item, the Main Map Window displays the location of all the drillholes of the Deep Sea Drilling Project (DSDP) Legs 1 through 96, comprising holes 1-624.
DSDP and ODP data are available via the General Data Viewers selection on the Available Data menu -> Tables -> Seafloor Sediments -> Ocean Floor Drilling.
A detached Spreadsheet Window appears separate from the Main Map Window. Each row in the spreadsheet corresponds to a drillhole visible with the region displayed in the Main Map Window. Thus zooming into a smaller region in the Main Map Window reduces the number of rows (drillholes) in the scrollable Spreadsheet Window.
Click on a symbol on the map and the drillhole selected is highlighted in red on the map and is shown on the top line of the spreadsheet. Alternatively, click on a table entry and the map symbol is highlighted.
Clicking on any column name causes the spreadsheet to be sorted for that item. It also highlights on the map all the drillholes containing a value in that column.
The Spreadsheet Window can be scrolled horizontally to reveal 51 columns that present different observations in the drill cores. For example clicking on the column head B_FORAMS (Benthic Foraminifera) will highlight in red on the map all drillholes with reported Benthic Foraminfera. The rows will be sorted to bring the holes with Benthic Foraminifera to the top of the spreadsheet. All drillholes that contain Benthic Foramifera will have their box checked and be highlighted light blue. You can click on a column heading and drag that column left or right to re-arrange the order of the columns. This is useful to bring three or four columns of interest together.
Clicking on a dot on the map causes that drillhole to scroll to the top row of the spreadsheet. That row is then highlighted in light blue to show that it has been selected. The columns after crustal age are arrange alphabetically from left to right.
Vice versa, clicking on a row in the spreadsheet causes that drillhole location to appear as a red dot in the Main Map Window.
Composition Interface
Press
to open the composition dialog in a separate window.
Open one of the subheadings ("minerals" shown), select an item, such as "quartz", and click load. The item appears in the pull-down in upper-right corner. You may select as many items as you want; they will be added to the pull-down. load reads a table with all analyses of the selected compositional item for all samples from all DSDP holes. 
closes the item and removes it from the pull-down. 
toggles whether all holes are plotted, or only those with analyses of the selected item in the age range (in millions of years) given below the slider. If 
is un-selected, sites where the item was observed in the age range show up red; if selected, those items are colored with a rainbow color scheme where 0% = blue and 100% = red. To change the displayed age-range, move the slider by dragging it, pressing the arrow keys, or clicking above or below the knob. By default, the age range interval is 10 Ma, the range is 0-200 Ma, and the step is 1 Ma. These parameters can be adjusted by clicking the Properties button. If multiple items are loaded, then click the pull-down and press the up or down arrow keys -- the map updates as different items are highlighted.
Example: item = quartz, age interval = 105-65 Ma (Upper Cretaceous)
This demonstrates that windblown sand from the Sahara was significant in the upper Cretaceous.
Age-Depth Models
The composition interface would not be possible without models of age vs. depth. These models were developed using a dialog that opens with the 
toggle-button on the tool bar above the DSDP table.
The graph shows the Geologic ages that are given in the DSDP tables from NGDC (pink boxes), fossil datums from fossil range charts (which may be turned off and on), and the age-depth curve. The graph may be scaled in various ways, and (age, depth) control points may be modified (dragged), added and deleted, to refine the model. The model may be saved.
At present, modifying the model has no effect on the model used by GeoMapApp, but in the future, users will be able to select from various age models, including ones they develop themselves, and to submit their models to GeoMapApp so they may be published for others to use.
This interface will be developed further. Additions will include:
- Adding more age determinations (e.g., radiometric dates, dated ash layers) to the graph.
- Adding panels showing variations of composition, lithology, physical properties, etc. with depth. These will be added to the right of the age-depth plot, with the same depth offset and scale.
- An option will be added to invert the axes, so that properties will be displayed as a function of age.