Method for Comparing Core Photographs from Multiple Drill Holes

This document is a description of a method for examining core from multiple diamond drill holes through the use of sequences of close-up photographs and storage and presentation of the collected photographs. The concept is similar to the use of chip boards to display rotary drill core lithology and mineralogy.

Detailed close-up photography should be in addition to not in lieu of routine core-box-scale photography as the two methods serve seperate functions.

The photographs can come from a program combining specific gravity determination and close-up photography or simply in conjunction with routine core logging.

A critical factor in a core photography program is that both the usual and the unusual need to be recorded preferably in proportion to their abundance. If photography is done routinely at relatively small inervals, and not just when something interesting is seen, then the collection of photographs will be representative of the rock drilled. As expressed in the Second Law of Hand Specimens - The number of specimens collected by the end of the season is inversely proportional to the abundance of the rock type in the area. And its corollary - The season may end without collecting a specimen of the dominant rock type. [Quarterly News Bulletin, Geological Society of South Africa, v. 12, no. 4, p. 17.]

The method of presentation that I have selected for routine display and examination of sequences of core photographs is the internet and world-wide-web HTML page format. There are several advantages to this method: easy storage and retrieveal on computers, portability across computer operating systems, and simple backing up or copying for use by multiple personnel at multiple locations.

The illustrations on the following pages show subsets of approximately 1650 photographs from five diamond drill holes all of which can be accessed from a single interface.


No. of Images


This first screen shot shows vertical aligned strips of photographs for five DDH holes. In this example there are 100 or more photographs for each drill hole and only a few can be seen at any given time. The additional photos can be seen by dragging down the slider bars on the right sides of each drill holes individual window. Individual holes can be accessed by clicking on one of the top, horizontal window's, row of button bars.

The photographs for the interval from 440 to 463 in drill hole K-272 are shown in the left vertical window in the next screen shot. For the purposes of this exercise the interval of interest is the bottom of the zone of oxidation and the other drill holes will be searched to find photographs from this interval. The bottom of the zone of oxidation is at about 235 feet in drill hole K-272.

The bottom of the zone of oxidation is at about 126, 107, 147, and 30 feet in drill holes K-273, K-287, K-292, and K293 respectively as can be seen in the next screenshot. The last three samples of oxidized rock are shown at the top of each vertical column and several samples from below the horizon are shown below the bottom oxidized sample.

A closer view of the rocks at the base of oxidation in DDH K-287 is shown in the next screenshot. This view was obtained by clicking on the button for K-287 (as shown in the first screenshot in this document) and scrolling down to the interval of interest.

The last screen shot is at maximum magnification and shows the mixture of pyrite and limonite in the sample from 160 feet depth in Drill Hole K-287.