1. Introduction

1.1. Purpose of the Correlator application

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. 

1.2. The SCORS ecosystem

On the JOIDES Resolution (JR), the Correlator application is used as part of the stratigraphic correlation support (SCORS) ecosystem. Additional software applications used in conjunction with Correlator are covered in a separate user guide (Table 1-21, Fig. 1-21). 

Table 1-21. Stratigraphic correlation support (SCORS) applications and documentation

2. Manage data in Correlator

3. Depth shift cores

4. Construct the splice

4.1. Splice concepts

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4.2. Create a basic splice

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4.3. Insert a core into an existing splice

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4.4. 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. No worries, Correlator will guide you through the process of fixing the gaps and overlaps! 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 depth 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 shallowest of 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:
  • "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 new splice interval boundary is defined at the CCSF depth scale, from which we can obtain 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.
  • For the first two options, this is done with 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:
    • 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 shallowest of 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:
  • "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 new splice interval boundary is defined at the CCSF depth scale, from which we can obtain 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.
  • For the first two options, this is done with 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:
    • 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

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Shift 'This core only' up

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4.5. Manage splice tables