392
Mulder and Cochonat ( 1996 ), E5 can be subdivided in two
successive mass wasting deposits: (i) fi rst, a pluri-metric and
erosive slump deposit remolding more or less deformed
lacustrine sediments, and (ii) secondly, a pluri-decimetric
greenish and fi ne grained turbidite. This turbidite is bear-
ing a well-preserved and normally graded sandy base at
325 cm below the lake fl oor in PAV99, but is essentially
made of a similar greenish and massive fi ne-grained sequence
on both piston cores. The slump deposit and this fi ne-grained
turbidite sequence are also clearly thinner in PAV12 than in
PAV99, suggesting that the latter piston core is localized in a
more proximal position than PAV12 from this mass wasting
event E5. A classical fi ning upward pattern within the fi ne-
grained turbiditic sequence retrieved in PAV12 is nicely
illustrated by increasing b* values (Fig. 23.5 ). This is sug-
gesting that this large and erosive mass wasting event remo-
bilized and re-suspended a signifi cant volume of lacustrine
sediments within the water column, before massive settling
occurred in the deep central basin of this maar lake.
Coarser but similar turbidite deposits are also identifi ed
in the basal grey unit retrieved in both piston cores from
Lake Pavin central basin (Figs 23.2 and 23.5 ). These light-
greyish turbidites are characterized by pluri-centrimetric
thick sandy bases bearing some few gravel particles
composed of similar volcanic materials than the Pavin crater
formation retrieved at the base of PAV08. While PAV99 only
contains one single turbidite between ca. 1050 and 1100 cm
core depth, up to three similar turbidites are found at the
base of PAV12. Their coarse-grained sandy bases are capped
by a fi ning upward sequence that is centimetric to decimetric
in thickness, fi ne-grained and systematically characterized
by progressively increasing b* values. In PAV12, these tur-
bidites are intercalated in between fi nely laminated and
light-grey colored sediments (high L* and b* values) that are
bearing low TOC and high Ti values (Fig. 23.5 ). It is alsoOrganic
upper unitsReworked
unitsMineral
basal unitsOrganic
lower unitsPAV99Erosive event7000 6000 5000 4000 3000 2000 1000 05000 4000 3000 2000 1000 0 1000 2000cal BC - ADcal BP4500 3500 2500 1500 500 500 150014 C age
14 C age rejected
Spline interpolation with
95% confidence intervalsIn-situ Laminated units
Reworked
material
Calibrated ageAD 2012HiatusPAV12
Age-depth modelE5 : ca. cal AD 1300Varve
counting(^18001700) Cal BP1600 1500
BP 1730 +/- 30probability
95%
(^28002600) Cal BP 2400 2200
BP 2400 +/- 30probability
86.5%
4000 3800 3600 3400
BP 3400 +/- 30probability : 95%
Cal BP
4600 4400 4200
BP 3940 +/- 30probability : 87%
Cal BP
(^54005200) Cal BP5000 4800
BP 4400 +/- 40probability :87%
7500 7000 6500
BP 6090 +/- 40
probability80.1%
Cal BP
300 200 100 0
BP 150 +/- 30probability : 29.9%
Cal BP
Cal BP
PAV09-B1
PAV12
PAV12
PAV12
PAV12
PAV12
PAV08
PAV12
PAV12
PAV99
PAV99
PAV12PAV09-B1
PAV09-B1
(^6500) Cal BP 6000 5500
BP 5250 +/- 35
probability59.3%
(^300200) Cal BP 100 0
BP 220 +/- 30probability : 44.5% PAV12
PAV12
BP 2195 +/- 35probability
95%
PAV12
(^2400) Cal BP 2200 2000
0
9
14
13
12
11
10
8
7
6
5
4
3
2
1
PAV12 PAV09-B1 FC1-3
Depth (m)
Fig. 23.6 Age depth model of core PAV12 based on AMS radiocarbon
ages from organic macro remains using the Intcal09 calibration curve
from Reimer et al. ( 2013 ), the identifi cation of reworked deposits inter-
calated within the central basin fi ll and the application of a spline inter-
polation between the dating points using the CLAM software (Blaauw
( 2010 ). Varves counting established on a twin core retrieved from deep
basin of Lake Pavin (Schettler et al. ( 2007 ) is supported by two radio-
carbon dates (one from PAV09-B1 and one from PAV12). Grey squares
correspond to reworked material associated with sedimentary events as
discussed in the text
L. Chassiot et al.