Import Drillholes from Text Files

Summary

Imports subsurface drillhole or borehole data from text files (.csv, .txt, or ASCII) to a feature dataset in a geodatabase.

Usage

The imported drillhole data will be stored in a feature dataset (called "Drillholes" by default), with feature classes created for each data type that is associated with the imported drillholes:

Collars (point features, surface location of each drillhole)
Traces (polylines, created from collar and survey data)
Interval data sets ("from-to" data line segments of varying lengths along the drillhole trace, with attributes)
Point data sets (point features that are located along the hole trace, with attributes)

Before importing drillholes from text files, you are asked to choose the output geodatabase in which to store the drillhole data and the spatial reference system that will be assigned to the feature dataset. You can also choose how to treat any existing data, if this is a second or subsequent import. If drillhole data already exists in the current drillhole dataset, the option to overwrite or append to existing data will be made available.

Parameters

Parameter	Explanation	Data Type
Import into existing Drillhole dataset	This determines if the import will create a new drillhole dataset, or if the data will be imported into a pre-existing drillhole dataset: Unchecked - the data will be imported into a new drillhole dataset. The new output dataset name must not already exist in the selected geodatabase. Checked - the data will be imported into a pre-existing drillhole dataset and can either replace, or append the existing data.
Output Drillhole Dataset	The name of the geodatabase feature dataset in which to store the imported drillhole data.
Spatial Reference (Optional)	The coordinate system (CS) to be used to spatially reference the imported drillhole data. Click on the Select coordinate system button to select the appropriate CS from the available options or add a new one. Not available if drillholes exist already in the drillhole feature dataset.
Existing data	If the data will be imported into an existing drillhole feature dataset, this determines if the newly imported data will overwrite existing data, or not: Overwrite - replace all existing data.The existing data will be overwritten; the drillhole feature dataset is deleted and recreated. Append - import new data only. The existing drillhole feature dataset is preserved; see the Technical Notes section below for more details.
Use import template files?	This determines if the import will use pre-existing templates or the import wizard to import the data: Unchecked - the import wizard is produced to select the source and type of data to import. New import templates will be created and saved for future use. Checked- the existing template files will be used to specify previously used import parameters. The source data files will be automatically loaded if templates are used.
Collar data	Drillhole collar data defines the surface location of a drillhole. Collar data has 5 required fields: Hole ID (a unique string that is also used in the other data tables) X Location (sometimes also called Easting) Y Location ( Northing) Z Location (Elevations) Total Depth (End of Hole, or Total Length) Collar data can also include Azimuth, Dip, and various attribute fields. Geographic (latitude, longitude) locations are not supported for collar locations.	Text File (.csv, .txt, ASCII)
Survey data	Drillhole survey data contains drillhole deviation information, and requires 4 fields: Hole ID (a unique string that is also used in the other data tables) Depth Dip Azimuth Survey data is optional. See the Technical Notes section below for more details.	Text File (.csv, .txt, ASCII)
Interval (from-to) data	Interval, or "from-to" data is data acquired over specified depth intervals ("from-to" depths) down the hole. This can be categorical data such as lithology, weathering, alteration or mineralization, or numeric data such as geochemical assays. From-To data must include the Hole ID, Depth From, Depth To and some type of attribute data values.	Text File (.csv, .txt, ASCII)
Point (depth) data	Point data or single depths data is acquired in discrete measurements made at specific depths. This can be structural data measurements, or geophysical logs. Point data must include the Hole ID, Depth and some type of attribute data values.	Text File (.csv, .txt, ASCII)
Template	The template file (with a file extension"i4") to be used to import the data file. Enabled if Use import template files? is checked.	I3 File (.i3)
Import File	The input data file corresponding to the selected Template file. template. Enabled if Use import template files? is checked. If a data file corresponding to the input template file is not located under the same folder, the Template field will be flagged.	Text File (.csv, .txt, ASCII)

Technical Notes

Template Files

Drillhole data that has been previously imported to any version of Target, may have saved template files. Import template files contain all of the import parameters including data source type (e.g. Excel, Access), data source location, and the type of data (Collar, Survey, From-To, Point), so these import parameters do not need to be specified again. These templates are useful to re-import data using the same settings, or to import new data with the same formatting. If no import templates are provided, the import wizard ('Drillhole Import') will be shown to select the type and format of the data to be imported.

Learn more about Template Files.

Desurveying Drillholes using Collar and Survey data

The drillholes are always "desurveyed" on import, which means a 3D spatial object (a drillhole "trace") is calculated for each drillhole. The output trace for any given hole can vary depending on what type of data is available during import (collars only, vs. collar and survey data) and which method is selected to do the desurvey calculations, as well as the resolution value selected. The various ways to calculate the traces, depending on which types of data are available, are described below:

With collar locations only, no survey data present:

If collar data includes dip and azimuth, these values are used to create straight segment traces for the entire hole, to the final depth.
If collar data does not include dip and azimuth, the holes are assumed to be vertical.

With collar locations and dip-azimuth survey data:

The survey data is "discretized" at the desurvey resolution interval value and a smooth curve is generated using the selected desurveying method (the default is the "Radius of curvature" method). See Drillhole Settings for more details.
Holes are 'desurveyed' and the new trace geometries are stored in the Traces, Depth Ticks, From/To and Point datasets.
The top-of-hole dip and azimuth values (at depth = 0) will use the values from the Survey feature class, if present.
If top-of-hole survey values are not present, the collar dip and azimuth values will be used instead (with the collar values taking precedence).

Learn more about Resurvey Holes.

Append New Data to Existing Dataset

When drillhole data is imported into an existing drillhole feature dataset:

If the import data contains a hole which did not previously exist in the dataset, the new hole is added.
If data is imported for a hole which already exists in the dataset, and the depths in the input data are greater than those in the original data, then the new data is appended to the original data.