What exactly is diamond drill hole data?
Drill hole data refers to the information obtained from drilling into bedrock during mineral exploration. Since bedrock is often covered by overburden, direct observations of the subsurface are limited. Diamond drill core provides direct, continuous information about the local geology with detailed geological and geochemical analysis. Reverse circulation (RC) drilling provides a set of rock chips associated with each predefined interval.
This data is available in three main forms: physical rock cores or chips, documented geological interpretations (logs), and numerical measurements such as geochemistry, magnetic susceptibility, hyperspectral data, etc. These datasets form the basis for building geological models and resource estimates, determining the viability of a mining project.
How is the data collected?
Data Collection for diamond drilling data from drilling the core (A), to logging the core (B), and receiving the assay results from the lab (C)
Data collection begins with a drill rig positioned over a target location, drilling into the earth to extract rock cores or chips in approximately 10-foot sections.
The rock is placed into boxes and delivered to the geology team for detailed logging. The geology team will manually log relevant details, such as lithology, structures, alteration, mineralogy, and many more into the geology database and photograph the core.
The core is sampled at regular intervals then split in half, with half of the core sent to a lab for geochemical assay, and the other preserved on-site for future observations. At the lab, the samples are dried, crushed, split, pulverized, and dissolved before being assayed according to the method selected by the client. Assay results are provided back to the client as a CSV file database import.
What is the support of the data (point, vectors, grids, etc.)?
Diamond drill data is typically interval data, with a start and end point along a drill string. This creates a line type vector data. The assay data is also a data interval consisting of the start and end of the cut material that was sampled. This interval can also be plotted along the drill string to identify high-grade zones within the deposit.
Individual intervals can also be converted to points by desurveying the drillhole to extract midpoint coordinates of each sample range or by generating a set of points at regular intervals with the associated values from the intervals.
Drill strings coloured by lithology and geology solid model:
Assay data colored and sized according to assay value:
Drill strings colored by assay value and grade shells:
Ref: KGET.com
How is this data typically displayed in geoscientific software?
Drilling and assay data are typically displayed on drill strings in a 3D environment that can be sliced into different sectional views. Lithology data can be colored by category, with the option to modify each color independently, allowing users to group different lithologies for visual evaluation. Users can further adjust transparency, color, and size for individual layers to refine their interpretation.
Assay data can be analyzed both statistically and within the 3D viewer, helping to identify high-grade sections. Selections can be made on histograms or scatter plots and displayed within the 3D viewer. A wide range of gradational, diverging or stepped color scales can be applied or manually constructed to view the data however the user desires.
What does it mean for geologists targeting mineral systems?
The drill hole data is used by the project geology team to interpret the deposit area and guide future exploration. Since data may be limited, the lithology model can be interpreted in various ways and is subject to change as new data emerges. With each new drillhole, new information about the subsurface is collected and used to either confirm or adjust the deposit model. Favorable lithologies or structures may indicate that the team is on the right track towards discovery. High-grade assays can indicate that the team has found a deposit and can define its extents. Whether a significant discovery or not, all information is collected and used to better understand the local geology.
Drill strings colored by lithology with lithology model:
Drill strings with assay values and block model grade estimations:
Drill string with assay values within pit design:
How is this used in the VRIFY AI targeting workflow?
Assay data is absolutely essential to generating the VPS results. The drilling assay results are accurate, uninterpreted measurement of the subsurface, and serve as the primary input for learning points and QAQC testing in VRIFY AI. The learning points are generated by selecting a cutoff value from the assay data, determining whether a sample is mineralized or unmineralized. This learning data is used to train and test the model to identify potential VPS targets in the local area. Without assay data, the VRIFY AI platform would not have an unbiased, primary data source to train the model to select potential targets.
The geology model including lithology, mineralized zones, alteration and others, are an important data set to the exploration team, but are not crucial for reliable VPS results. The geology model is a very interpretive dataset and can be built up over many years by multiple geologists. This type of data is prone to data errors and inconsistencies between different members of the team. The best VPS results are produced using unbiased and consistent data sets so as to not provide the model with conflicting information.
Still have questions?
Reach out to your dedicated VRIFY AI Contact or email Support@VRIFY.com for more information.