Oriented core and conventions

Oriented drill core is measured as alpha and beta angles, and the convention for them is not standardised: the same numbers can mean different planes at different sites. Check the convention against structures of known orientation before you trust any chart.

1. Choose alpha / beta: Set the measurement type to alpha and beta. The file also needs the hole’s orientation (trend and plunge) and, ideally, the dip and dip direction the site calculated.
2. The settings: Where beta is measured from (the top or the bottom of the core), which way it increases, whether alpha is measured to the plane or to its pole, and which end of the ellipse is used.
3. The convention check: Compares the planes your settings give with the dips the site calculated, tries every convention and reports which fits. Apply the best fit with one click.
4. Known-orientation test: Type in one structure of known orientation (alpha, beta, hole and its true dip and dip direction) and see which conventions reproduce it.
5. Checked or assumed: The status beside the chart says whether the convention was checked against known data or only assumed. Report assumed conventions as assumptions.