2nd May 2008, 10:28 AM
I think it must be to do with recuts, as Angie said.
Primary, secondary and tertiary fills may also be understood from a taphonomic perspective and not just as a sequence of fills bottom to top in the chronological sense.
In the former case, a primary fill constitutes the first process of deposition in a feature, such as a pit. Normally this is the breaking in of the side of the pit so that the primary fill is composed of redeposited natural, which ought to be sterile (that is if there isn't an intentional dumping/ deposition due to human agency occurring in the pit).
The secondary fill can taphonomically be understood to represent the erosion of surrounding topsoil into the pit, which will include residual cultural material.
The tertiary fill will then be represented by the deposition of material that is deposited through wind- or waterborne deposition, effectively sealing the feature (the latter may not always be present due to later erosion/ truncation of the feature).
If a re-cut occurs, the same sequence of processes will obviously re-occur, so that a second 'primary fill' can occur above a secondary fill in a feature.
In a normal case scenario, i.e. whenever humans didn't interfere with the natural process by depositing or dumping material or recutting, primary-secondary-tertiary fill will represent the bottom-to-top sequence.
I think this is all based on observations taken from experimental case studies.
Primary, secondary and tertiary fills may also be understood from a taphonomic perspective and not just as a sequence of fills bottom to top in the chronological sense.
In the former case, a primary fill constitutes the first process of deposition in a feature, such as a pit. Normally this is the breaking in of the side of the pit so that the primary fill is composed of redeposited natural, which ought to be sterile (that is if there isn't an intentional dumping/ deposition due to human agency occurring in the pit).
The secondary fill can taphonomically be understood to represent the erosion of surrounding topsoil into the pit, which will include residual cultural material.
The tertiary fill will then be represented by the deposition of material that is deposited through wind- or waterborne deposition, effectively sealing the feature (the latter may not always be present due to later erosion/ truncation of the feature).
If a re-cut occurs, the same sequence of processes will obviously re-occur, so that a second 'primary fill' can occur above a secondary fill in a feature.
In a normal case scenario, i.e. whenever humans didn't interfere with the natural process by depositing or dumping material or recutting, primary-secondary-tertiary fill will represent the bottom-to-top sequence.
I think this is all based on observations taken from experimental case studies.