# (Ekofisk abiotic data)

For the 39 sites around the Ekofisk oil-field, environmental data is available on concentrations of total hydrocarbons and metals such as Barium, Strontium, Copper in the sediments, and measures of physical sediment properties, such as % mud; also the distance from the oilfield centre is another variable in this array. These are in the Excel file <ins>Ekofisk environmental.xls</ins>:

[![ScreenshotPage30a.png](https://learninghub.primer-e.com/uploads/images/gallery/2024-05/scaled-1680-/screenshotpage30a.png)](https://learninghub.primer-e.com/uploads/images/gallery/2024-05/screenshotpage30a.png)

Note that there is only one sheet defined in this case (‘Environmental’), it is in the form samples $\times$ variables with the same (unique) labels for the sites as in the assemblage data, which can be of any length and consist of a mix of numbers, letters and spaces (as can the title be, if present), but data entries must always be <u>strictly numeric</u> (e.g. ‘<’ signs are not permitted).