Lake Pavin History, geology, biogeochemistry, and sedimentology of a deep meromictic maar lake

149

The ages of the four volcanoes, namely crater Pavin,
Montchal, maar d’ Estivadoux , and Montcineyre , were esti-
mated by means of a Bayesian approach developed in the pro-
gram RenDateModel by Lanos and Dufresne ( 2012 ). This
method allows combining together ages obtained by various
techniques and it can take stratigraphic constraints into
account (e.g., see Blockley et al. 2008 ; Lowe et al. 2013 ).

Actually, such constraints are very strong in the present case

as outlined earlier. For sake of processing real years, the

RenDateModel soft will begin by calibrating the radiocarbon

conventional results (B.P.); for that purpose, the data from

Intcal09 (Hughen et al. 2009 ) were used in the present work.

Table 8.1 shows the data assumed as reliable and put in

the calculations. The fi ve results for Pavin were measured on

Table 8.1 Age data used in the present work

References

(Articles) Volcano and site Material

Age reference

(Lab. No)

14 C result

(B.P.)

Calibrated date

interval (B.C., 95 %) Comments

Pavin

Juvigné et Gillot

( 1986 )

Col de Chamoune

(peat bog)

Peat. Tephra

centred in the

sample

Lv 1491 =5680 ± 100 4340 4230

Juvigné et Gillot

( 1986 )

Col de Chamoune

(peat bog)

Peat. Tephra

centred in the

sample

Lv 1492 =5990 ± 80 5110 4690

Juvigné et Gillot

( 1986 )

Redondel (peat

bog)

Peat. Tephra

centred in the

sample

Lv 1493 =5710 ± 90 4720 4360

Gewelt et Juvigné

( 1988 )

Narse d’ Ampoix ,

(peat bog)

Peat. Tephra

centred in the

sample

MBN 327 =5990 ± 140 5220 4550

Gewelt et Juvigné

( 1988 )

Landeyrat (peat

bog)

Peat. Tephra

centred in the

sample

MBN 382 =6000 ± 110 5210 4650

Juvigné et

Stach-Czerniak

( 1998 )

Tazenat (crater

lake)

Very organic

mud. Tephra

centred in the

sample (30 cm

thick)

LV-2174 <6770 ± 80 Partially reworked

older sediments?

Chapron et al.

( 2012 )

Bottom of lake

Pavin (sediment

core)

Leaves Poz- 27050 >4995 ± 35

Chapron et al.

( 2012 )

Bottom of lake

Pavin (sediment

core)

Leaves Poz- 27051 >4820 ± 40

Montcineyre

Juvigné et Gillot

( 1986 )

Peat bog # 16 Peat beneath the

tephra

Lv 1522 <6530 ± 100 5480 5060

Juvigné et Gillot

( 1986 )

Peat bog # 10 Peat beneath the

tephra

Lv 1523 <6520 ± 100 5630 5310

Gewelt et Juvigné

( 1988 )

Redondel (peat

bog)

Peat. Tephra

centred in the

sample

MBN 383 =5750 ± 110 4830 4360

Gewelt et Juvigné

( 1988 )

Auzolle (peat bog) Peat. Tephra

centred in the

sample

MBN 389 =6180 ± 125 5380 4800

TL (real

age)

B.C. Interval (95 %)

Montcineyre
Guérin ( 1983 ) Compains Feldspars (lava) MD 73 =8500 ± 400 7290 5690
Montchal
Guérin ( 1983 ) Road CD # 149 Feldspars (lava) MD 127 =7560 ± 385 6320 4780
Explanations: ‘=’ means that the tephra layer was centered in the dated peat sample (same thickness above and beneath the tephra); it can then be
assumed that the measured age is very close to the age of the tephra; ‘<’ means that the age is a maximum one for the tephra because the peat was
sampled beneath the tephra; ‘>’ means that the age is a minimal one because the measured peat sample is younger than the tephra. For homogeniz-
ing the display (column # 5), TL error limits are given as for^14 C at the 68 % confi dence level. The assessed relative chronology, beginning by the
oldest eruption is as follows: Montcineyre , Estivadoux , Montchal, Pavin. E is the thickness of the sampled peat

8 Distribution, Tephro- and Chronostratigraphy of the Widespread Products of Pavin Volcano