Define Strata

Define Strata serves several purposes. It is an optional settings/configuration file that defines strata and bed hatch patterns, Key status, density, conformance modeling settings, and bed splitting settings. Without the strata definitions predefined, StrataCalc commands will use defaults.

Define Strata is a dialog based spreadsheet editor for strata definitions. The first window shows a list of all of the currently defined strata. If no strata are yet defined, this table will be empty. This command is used to define both Strata, such as COAL and Beds, such as C_KEY. To add a new strata definition, click on the Add button. This brings up the Strata Definition dialog. To edit an existing strata definition, highlight the corresponding line in the table and then click on Edit button which also brings up the Strata Definition dialog. To edit the same property for multiple strata such as the Hatch Scale, highlight multiple rows in the spreadsheet by picking with the Ctrl and/or Shift keys, and then pick the Edit Multiple button. You can also use the standard Windows Copy and Paste functions to edit cells in the spreadsheet. To remove a definition, highlight the corresponding line and then click on the Remove button. The Sort button will sort the strata either by name alphabetically, or by following the Geologic Order file that is created with the Define Geologic Order command. The Draw Legend button will draw a legend of the selected strata. The Read Drillholes button will read the selected drillholes and add a default definition for any strata names found in the drillholes that are not already in the table. The Read Model button will search the Geologic or Mining Model for strata names and put them on the list. The Save and Save As buttons exit Define Strata after saving all the changes in the current session to the strata definition file (.sdf file). The Exit button exits Define Strata without saving.

Draw Legend brings up the selection window to choose which items to display in the legend. Then the legend location is selected.

The Column Options button displays the window to select which columns appear in the main Define Strata Screen.

• Strata Name: This is the strata or bed name that is used to match up with the names in the drillhole. Enter in the strata names exactly as they appear in the drillhole. For bed names, there are four extensions or suffixes that must be added to the bed name to match up with the interval of the bed in the drillhole. They are as follows: LI_TOP, LI_KEY, LI_PARTING, and LI_BOTTOM. These must also be entered below, in the target and marker strata windows, and in the strata split names when using bed names. The strata name may use wildcards. This allows fewer strata definitions. The strata list is automatically sorted to place the most general matches in the end of the list. This concept is illustrated in the following example:

  Strata definitions: C1, C?, C*, *

  Strata in drillhole: COAL, SAND, C2, C1, C12

  Applied Matches:

  COAL C* This is the least general match to the COAL. '*'=anything

  SAND * This word begins with 'S' and all other keys begin with 'C'

  C2 C? '?'=any one symbol, so C? is less general than C*

  C1 C1

  C12 C* C? does not match because of extra symbol on the end.

• Full Name: This is the name that will appear as an option in reports and other strata selection windows.
  
• Layer: This is the AutoCAD layer that will be created and used for this strata or bed.
  
• Select Color: This is the color that the solid or hatch pattern will be drawn in for the layer entered above.
  
• For Background: If this is checked, then the background will be a solid fill in the color specified. The hatch pattern will appear on top of it in a black color.
  
• Hatch Name: This is the name of the selected hatch. A preview of it shows up next to the Select Pattern button.
  
• Hatch Scale: This is the scale factor used to size the hatch pattern.
  
• Hatch Azimuth: To rotate a hatch pattern, enter in an azimuth. 90 is horizontal and the default.
  
• Density: Enter in the strata density in pounds per cubic foot or in kg/cubic meter. This is used in Mine Reserves. If no density is set in the strata definition, the program displays "BY_DRILLHOLE" which means that key-strata density of the drillhole will be used. This key-strata density is set by Define Drillhole and can be viewed or modified with Edit Drillhole.
• Select Pattern:  This button brings up the predefined 127 geologic hatch patterns of Carlson. Each screen with 20 patterns is shown below. Just click on the one to select for each strata or bed. 

• Type of Strata: The Key or NonKey status can be set here, by strata or bed, which is used by Place Drillholes to determine the type of the user-specified strata name. Also, while entering strata names in Place Drillholes, the strata definitions are checked to see that the strata names are already defined. If the strata name is undefined, the user can define it from there, leave it undefined, or re-enter the name. This check avoids typos and ensures that the strata names match since they should be consistent for the same strata across the drillholes.
• Recovery Percent: A recovery can be set for each strata or bed here. It is used in reserves and scheduling.
• Non-Key Thickness To Add To Key (Dilution): These values apply to the Use Strata Definitions option in the Surface Mine Reserves and Geologic to Mining Model commands.
• Key Thickness To Remove From Key (Loss):  These values apply to the Use Strata Definitions option in the Surface Mine Reserves and Geologic to Mining Model commands.
• Use for modeling (pinch out/conformance): Turn on this option if the seam is to be used in modeling the drillholes for pinch out and conformance.
  
• Use as seam-specific conformance marker: Turn on this option if this is a "dominant" marker seam that other seams should conform to if needed.
  
• Target strata: Specify the "target" strata to conform to this marker bed. Enter the strata names, with spaces between the names. It they are beds, use the extensions _TOP, _KEY, _PARTING and _BOTTOM.
  
• Select: This will bring up a strata/bed list dialog box for easy selection.
  
• Marker Priority Level: This is the priority level for the marker bed. For example, the main marker bed A will have a priority of 1 for Seam C. Seam B is the next dominant, so seam B will have a priority level of 2 for seam C.
  
• Target of seam-specific conformance: This is defining the current seam as a target seam for a different marker seam. Meaning this is not the dominant seam, it will conform to another seam.
  
• Marker strata: Just as in Target Strata above, but the opposite applies; enter in the Marker seam for the current seam to conform to.
  
• Strata Split Names (Top and Bottom): Strata can be defined to split from parent into children strata for modeling. For example, if A splits into A1 and A2, they should be entered in the Top and Bottom Split windows. When modeling, the drillhole that has A will correlate to A1 and A2, with the parting pinching out as it models its way closer to the hole with A. To make sure it is working properly, the seam A should not appear on a list of strata to process. There will only be A1 and A2 for modeling. In case there are more splits, the program allows children strata to split again. For example, the strata definition for A2 can split into A2A and A2B. In Surface Mine Reserves, quantities for the children seams (ie. A1 and A2) are reported for areas that the split exists and quantities for the parent seam (ie. A) are reported for areas without a split. Also, Grid file utilities and other functions such as limit lines can be used to bring children strata "back" together to get a full parent seam.
  
• Additional Attributes: This function will define any attributes specific to that strata, which do not apply to other strata and therefore would be misplaced in the Define Drillhole. The list of attributes for particular strata will be combined from the attributes defined for define Drillhole (key or non-key attributes, depending on the strata type) and attributes defined in Define Strata. In addition the attributes specific for a strata in some drillhole may be added directly to that strata in Edit Drillhole or Drillhole Data Sheet. The equation attributes described in Define Drillhole may be used in this dialog as well.

Prompts

Strata Definitions Table 
Strata Definition Edit Dialog 
Strata Hatch Patterns 

Pulldown Menu Location: Drillhole in Geology, StrataCalc in the Mining menu
Keyboard Command: sdef
Prerequisite: None