APPENDIX

Calculation for Diatom Accumulation Rate

Diatom Accumulation Rate (valves/cm2 per k.y.) (e.g. Battarbee, 1986; Schuette and Schrader, 1979):

DAR = DMAR Cdw

Where:

DMAR = Dry Mass Accumulation Rate (g/cm per k.y.)
Cdw = diatom concentration per gram dry weight (valves/g)

Dry Mass Accumulation Rate (e.g. Battarbee, 1986; Schuette and Schrader, 1979):

DMAR = SR DBDsc

Where:

SR = Sedimentation Rate (cm/k.y.) (NB must be calculated for each core section to avoid problems associated with postdrill handling)
DBDsc = Salt Corrected Dry Bulk Density (g/cm3)

Concentration per gram dry weight (valves/g) (Battarbee and Kneen, 1982; Schuette and Schrader, 1979):

Cdw = Cd/W

Where:

Cd = diatom concentration (number of valves)
W = dry weight processed (g)

Diatom Concentration (by microsphere method) (Battarbee and Kneen, 1982):

Cd = (Ymi Xd)/Ymc

Where:

Ymi = number of microspheres introduced
Xd = number of diatom valves counted
Ymc = number of microspheres counted