Student guide

This guide is for students learning to read and make drillhole logs with Strip Logs. The help pages earlier in this manual say where each control is. This guide says what each control does to your data, what you will see, and why you would use it. It covers the app in four parts:

Words in bold are the labels you see on screen.

How the app is put together

The app works on one export workbook: an Excel file with one sheet per view of a drillhole database. The sheets are recognised by their columns, whatever they are called.

  1. The data source (top right: Demo or Upload) decides which workbook is loaded. The load line under the header says what it holds.
  2. The import reads every sheet and checks it. Nothing in your data is changed: what looks wrong is reported on the Data health tab, with why it matters and what to do.
  3. The Log tab draws one hole at a time. The left panel chooses the hole and its columns, and sets the rules (which logging, which assay result, below detection, intercepts). The log is on the right: the hole’s header, a column for each field on one depth scale, a legend, and the significant intercepts.
  4. Print turns the same log into a PDF at a true scale, laid out by the Template.
  5. Data shows any sheet as the app read it, so you can check a value at its source.

Everything is worked out again straight away. Nothing is saved on a server: your workbook stays in your browser session and is gone when you close the tab. This browser remembers your column choices and rules for next time.

A first session (about 30 minutes)

Work through this with the demo data before using your own. The demo is ten holes of masked data from one project (“Project J”).

  1. Load the demo. Top right, click Demo. The load line reads “Project J demo, 10 holes (masked data) (demo): 10 holes, 1,299 samples, 20,610 assay results, 6,200 geology rows”.
  2. Look at the first hole. On the Log tab, Hole shows J-000026 (238 m, 238 samples): the holes with the most assayed samples come first. Choose J-000030. Read the header above the log: the collar coordinates, the grid, the depth, the first survey’s dip and azimuth, and who logged the hole.
  3. Read the columns. From left to right: the lithology (each rock type in its colour and FGDC pattern, its name written in the block), the alteration, the gold and copper assays, the structures and the RQD. Every column shares the depth axis on the left: depth increases downwards.
  4. Zoom. Drag down over 10 to 30 m on any column. Every column zooms with it. Click Reset zoom to see the whole hole again.
  5. Find the gold. Under the log, Significant intercepts lists four intercepts, the first “6.0 m @ 5.56 ppm Au from 16.0 m”. Each is shaded blue on the Au column. Read the note under the list: it states every rule used, as a company would in a release.
  6. Change a rule. In Intercepts, change Cut-off from 0.5 to 1 and watch the list change. Set it back to 0.5.
  7. Look at structures. Choose hole J-000061. In the Alpha column, each structure is a short line at its angle to the core axis, leaning left or right by its beta angle, in its type’s colour.
  8. Check the data. Open the Data health tab. It lists 0 findings to fix, 9 to check and 28 for information. Select a finding to see the rows behind it.
  9. Print it. Back on the Log tab, under Print, click PDF of this log. Open the PDF: the log is at 1:200, over as many pages as the hole needs, with a legend and the method on every page.

By the end you will have read a log, found and changed significant intercepts, and checked where the numbers come from.

Good habits

  • Check Data health before you trust a log. A failed result, a relogged interval or a hole deeper than its collar depth all give a log that looks fine but is wrong.
  • Know which result you are looking at. A sample can have several assays: repeats, other methods, failed batches. The app shows one per sample, and the note under the log says which. Shaded intervals have no result that passed QC.
  • Report your rules. The cut-off, minimum width, maximum dilution, top cut and below-detection rule all change the intercepts. The note under the intercepts states them for you; copy it with the numbers.
  • Remember that widths are downhole lengths. A 10 m intercept in a hole that cuts the ore body at a low angle can be much less than 10 m thick.

When the app changes

The app is still developing. This guide is checked against the app each time the manual is rebuilt, and changes are listed in What’s new. If something on screen does not match this guide, the screen is right: please tell us through the Feedback tab.