Spacing refers to the distance between fractures or thickness of beds visible in the core. In the case of fractures, spacing does not represent the thickness of the open space produced by a fracture, but rather the amount of rock material between two distinct fractures. For bedding thickness, this represents the amount of rock material between two distinct bedding planes. Discontinuities, such as joints and fractures, are often found in crystalline rock that has undergone deformations. Whereas bedding terms are typically used for sedimentary rocks such as sandstones and limestones.

Table 4-8: Joint and Bedding Terms

Joint Term	Bedding Term	Spacing (inch)
Very Close	Laminated	< 0.5
Close	Very Thin	0.5 – 2
Moderately Close	Thin	2 – 12
Wide	Medium	12 - 36
Very Wide	Thick	> 36

Discontinuity spacing is the distance between natural discontinuities as measured along the borehole core. Evaluate the discontinuity spacing within each core run, and report on the boring logs in accordance with the criteria provided in Table 4-9 below. Do not include mechanical breaks due handling or drilling in the measurement of discontinuity spacing.

Table 4-9: Discontinuity Spacing

Description	Discontinuity Spacing
Very widely spaced	>10 feet
Widely spaced	3 feet to 10 feet
Moderately Spaced	1 feet to 3 feet
Closely Spaced	2 inches to 12 inches
Very Closely Spaced	Less than 2 inches