1. About Correlator 4.0

The Correlator application facilitates stratigraphic correlation of cores from multiple holes at a drill site. Its features support

• depth shifting of cores based on high-resolution core logging data, including images, to construct a core composite depth below sea floor (CCSF) depth scale; and
• splicing of selected core intervals to construct the most complete stratigraphic representation possible at a site. 

On the JOIDES Resolution (JR), the Correlator application documented here is used in conjunction with other applications within the stratigraphic correlation support (SCORS) ecosystem (Fig. 1-1), which are covered in a separate user guide (Table 1-1). 

Figure 1-1. Stratigraphic correlation support (SCORS) applications.

Table 1-1. Stratigraphic correlation support (SCORS) application documentation

Version 4.0 beta was released in April 2022. It can be downloaded at

<GitHub link>

On the JR you don't need to download the application - access will be obvious, or assisted by JRSO staff.

Correlator installs a directory for its internal database at a default location that looks something like this:

• Documents [or other system folder] > Correlator > 4.0 > db | default.cfg | log | temp

When you import correlation data from a directory of choice, Correlator indexes the data and places them in this directory for internal use. You don’t have to be aware of this directory but can change the path if needed (Fig. 1-2).

Figure 1-2. Correlator File menu.
 

Affine tables created in Correlator versions 3 and 4 differ from those in version 2: they include additional information (last three columns, see Appendix 2) that allow Correlator to reconstruct the relationship between cores. Affine tables created in the production version, 2.1_rc2 can still be imported in 4.0 by right-clicking "Saved Tables" in the Data Manager (available once data are loaded) and choosing Import legacy affine table. However, because legacy affine tables have no record of the reference core used to create a TIE, all cores shifted by a TIE will be converted to status REL on import into 4.0. This has no effect on their cumulative offsets, which will be preserved, but users will have to rebuild the TIEs manually (as was the case in version 2). 

2. Correlator basic functions overview

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3. Manage data in Correlator

3.0. Overview of data management functions

(Move up from 2.6.)

3.1. Import primary correlation data

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3.2. Import core section summary files

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3.3. Import core section images

Important:

• You must first import some primary correlation data (and the associated section summary data) before you can import images.
• The images must be JPEG format and in the order of ~200 kb each, which is sufficient for most correlation purposes. Try higher resolution at your own risk.

To import images:

• Right-click on Images in the Data Manager window.
• Navigate to your local data directory
• Select the folder containing the JPEG images you want to import and click import.

3.4. Load data for correlation

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3.5. Update Correlator data

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3.6. Export data

Export affine and splice tables

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Export correlation data

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Export spliced data and images

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4. Depth shift cores

4.1. Depth shift concepts

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4.2. Shift cores with the TIE method

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4.3. Shift cores with the SET method

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4.4. Undo shifts

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4.5. Manage affine tables

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5. Construct the splice

5.1. Splice concepts

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5.2. Create a basic splice

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5.3. Insert a core into an existing splice

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5.4. Change the affine during the splicing process

Ideally, depth shifting should be concluded before a splice is assembled. However, life is not ideal and you may want to shift a core after you have constructed a splice. Because splice intervals are defined by their CCSF depths, shifting their cores invalidates the splice interval boundaries. A core shift results in a gap, an overlap, or both in the splice, depending whether 'This core and all related cores below' or only a single core are shifted, and whether the core(s) are shifted up or down. Correlator will guide you through the 'splice repair options and reverse-compute the CSF-A depth of each section top using the cumulative offset (m) of the core, and then the offset (cm) from top of section.

Let's go through the four cases by example (Fig. X).

Shift 'This core and all related cores below' down

• Define a new tie from REF core A3 to SHIFT core B3 where the tie point in SHIFT core B3 is dz m shallower than the REF tie point in A3. This means the SHIFT core will shift down (Fig. X).
• Select “This core and all related cores below” and click OK:
  • Replaces the previous tie with the new tie and shifts core B3 with all related cores from all holes that are deeper than REF core A3 downwards by dz m, maintaining all ties below the new one.
  • Extends the CCSF scale by dz m.
  • Because this is a frequent and standard operation, no user dialog is triggered for the shift unless at least one of the cores A3 and B3 is part of a splice.
  • All splice intervals associated with the shifting cores also shift by dz. This is computationally done by adding dz to the CCSF depth of the splice interval boundaries. No change occurs to the sample identities (Hole-Core-Section-Offset) or the CSF-A depths of the splice interval boundaries, they remain as explicitly defined by the user.
• Because this action has extended the CCSF scale, a gap is created at the top of the splice interval representing the shifted cores. The gap can be covered completely with a segment from either core A3 or B3, or partially with segments from both cores - it is up to you to decide. Correlator offers you the options in a pop-up window (Fig. X):

Fig. X. Dialog for repairing a splice gap 

• • "This shift creates a gap in the splice. How do you want to proceed?’
    • Extend the splice interval from core A3 downwards
    • Extend the splice interval from core B3 upwards
    • Leave the gap and let me fix the splice manually
    • Cancel shift

• The first two options apply an “auto-fix”.  The calculated sample identity is validated and if the section-offset doesn’t actually exist in the same core, an error dialog is presented (Fig. X).

Figure X. Dialog for non-existent core interval. 

• • This solution is not valid, interval boundary falls outside the core.
  • Click the OK button and you return to the four options.

• The third option on the menu allows users to cover the gap with a combination of extensions from both splice intervals using the normal interactive splicing interface.
• The final option cancels the shift and nothing happens to cores or splice intervals.

Shift 'This core and all related cores below' up

• Define a new tie from REF core A3 to SHIFT core B3 where the tie point in SHIFT core B3 is dz m deeper than the REF tie point in A3. This means the SHIFT core will shift up (Fig. X).
• Select “This core and all related cores below” and click OK.
  • Results are analogous to those described in previous case.
• Because this action has shortened the CCSF scale, an overlap is created at the top of the splice interval representing the shifted cores. The overlap can be removed completely with a segment from either core A3 or B3, or partially with segments from both cores - it is up to you to decide. Correlator offers you the options in a pop-up window (Fig. X).

Figure X. Dialog for repairing a splice overlap. 

• • "This shift creates an overlap in the splice. How do you want to proceed?’
    • Clip the splice interval from core A3
    • Clip the splice interval from core B3
    • Leave the overlap and let me fix the splice manually
    • Cancel shift

• The first two options apply an “auto-fix”.  The calculated sample identity is validated and if the section-offset doesn’t actually exist in the same core, an error dialog is presented (Fig. X).

Figure X. Dialog for non-existent core interval.

• • This solution is not valid, interval boundary falls outside the core.
  • Click the OK button and you return to the four options.

• The third option on the menu allows users to remove the overlap with a combination of clipping parts from both splice intervals using the normal interactive splicing interface.
• The final option cancels the shift and nothing happens to cores or splice intervals.

Shift 'This core only' up

• Define a new tie from REF core A3 to SHIFT core B3 where the tie point in SHIFT core B3 is dz m shallower than the REF tie point in A3. This means the SHIFT core will shift down (Fig. X).
• Select “This core only” and click OK:
  • Replaces the previous tie with the new tie and shifts core B3 downwards by dz m.
• Because this action has not changed the total length of the CCSF scale, a gap is created at the top of the core and an overlap is created at the bottom of the core. The gap and overlap can each be repaired in two ways (see the first two cases) and Correlator therefore simply reminds you to do so yourself using the normal splice interface, or cancel the shift (Fig. X):

Fig. X. Dialog for repairing a single core splice gap and overlap.

• • "This shift creates a gap and an overlap in the splice. The splice interval associated with this core is therefore deleted and you need to splice it in again".
  • Cancel shift

Shift 'This core only' up

• Define a new tie from REF core A3 to SHIFT core B3 where the tie point in SHIFT core B3 is dz m deeper than the REF tie point in A3. This means the SHIFT core will shift up (Fig. X).
• Select “This core only” and click OK:
  • Replaces the previous tie with the new tie and shifts core B3 upwards by dz m.
• Because this action has not changed the total length of the CCSF scale, an overlap is created at the top of the core and a gap is created at the bottom of the core. The gap and overlap can each be repaired in two ways (see the first two cases) and Correlator therefore simply reminds you to do so yourself using the normal splice interface, or cancel the shift (Fig. X):

Fig. X. Dialog for repairing a single core splice gap and overlap.

• • "This shift creates a gap and an overlap in the splice. The splice interval associated with this core is therefore deleted and you need to splice it in again".
  • Cancel shift

5.5. Manage splice tables