A. Baker et al., Variations in stalagmite luminescence laminae structure at Poole's Cavern,England, AD 1910-1996: calibration of a palaeoprecipitation proxy, HOLOCENE, 9(6), 1999, pp. 683-688
Duplicate records of variations in the structure of stalagmite annual lumin
escence laminae are investigated for the period AD 1910 to 1996 for Poole's
Cavern, Burton, central England. For the two stalagmites, 88% of the years
have luminescence laminae that exhibit a near sinusoidal shape with no str
uctural variations. However 10 laminae (12% of total) exhibit a double band
structure; these are demonstrated to occur in years with high monthly or d
aily mean precipitation. It is suggested that high intensity (>60 mm d(-1))
and high quantity (>250 mm per month) of precipitation may flush luminesce
nt organic material onto the stalagmites from either the soil or groundwate
r zones and generate a double lamina. However, not all precipitation events
generated double laminae. High-intensity events in summer were ineffective
due to a soil moisture deficit and/or interception by the woodland canopy.
High-rainfall months (>250 mm) failed to generate double laminae when prec
eded by two or more months of greater than 150 mm, suggesting exhaustion of
the organic acid supply can occur. When compared to monthly precipitation
data for Burton, laminae shape and the percentage of double laminae of the
Poole's Cavern stalagmites are best explained by a centre-weighted running
mean of the preceding six to seven months' precipitation. The palaeoclimate
potential of structural variations in stalagmite luminescence laminae is d
iscussed.