From the Manual:
Working with Final Cut Pro XML Files
The Final Cut Pro XML format is used to import and export audio data between Final Cut Pro and Logic Pro. The Final Cut Pro XML format supports automation data.
To export the current project as a Final Cut Pro/XML file
μ Choose File > Export > Project to Final Cut Pro/XML. A standard dialog opens, allowing you to name the export file.
Note: AudioInstrumenttracksarealwaysbouncedtoaudiofiles.MIDItracksareignored. Bouncing will automatically switch to real-time mode, if necessary (such as when an I/O or External Instrument plug-in is used).
To import Final Cut Pro XML files
Do one of the following: μ Choose File > Import, then choose the file in the Import dialog. μ Locate and select the file in the Browser, then click the Open button.
The XML import procedure allows you to change or retain the sample rate of audio files used in your Final Cut Pro sequences. If you import sequences that use audio files with different sample rates, you are given the following options:
• To alter the sample rate of your Logic Pro project to match all imported Final Cut Pro sequence audio files.
• To retain the sample rate of your Logic Pro project. All Final Cut Pro sequence audio files that use a sample rate that differs from the selected one are converted.
Note: AFinalCutProsequenceisanarrangementofvideo,audio,andgraphicsclips,edit information, and effects. When combined, they create a movie. Use of XML to import Final Cut Pro sequences into Logic Pro allows you to exchange multiple audio tracks, with all positional region information, region names, and volume and pan automation data, retained.