FRAC: Fracture Spacing

• Class: Samples, Amalgamated Specimens and Laboratory Test Scheduling

Heading	Unit	Type	Example	Description
LOCA_ID		ID	327-16A	Location identifier
FRAC_FROM	m	2DP	31.2	Depth to top in hole, or distance to start on traverse, of the zone
FRAC_TO	m	2DP	33.65	Depth to base in hole, or distance to end on traverse, of the zone
FRAC_SET		X	J3	Discontinuity set reference
FRAC_IMAX	mm	0DP	350	Maximum fracture spacing over zone
FRAC_IAVE	mm	0DP	220	Average fracture (modal) spacing over zone
FRAC_IMIN	mm	XN	NI	Minimum fracture spacing over zone
FRAC_FI		0DP	15	Fracture Index / frequency over zone (fractures per metre)
FRAC_REM		X	2	Comments on fracture set
FILE_FSET		X	FS4	Associated file reference (eg logging field sheets)

Notes - 2

• FRAC is used to include fracture set details derived from rock core. Fracture information collected from scanline surveys of rock exposures or similar should be recorded in the DISC group.
• It is not typical to define fracture set spacing?s as both min/avg/max fracture spacing and Fracture Index. The requirement for one or other should be specified.