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

13 4

10

12

14

16

18

20

35 45 55 65 75

Al2O3

SiO2

0

1

2

3

4

5

6

7

8

35 45 55 65 75

Na2O

SiO2

0

1

2

3

4

5

6

7

35 45 55 65 75

K2O

SiO2

2

4

6

8

10

12

14

40 50 60 70

Na2O+ K2O

SiO2

Trachyte Rhyolite

Trachy-andesite

BasalticTrachy-

andesite

Trachy-basalt

Basalt

0

1

2

3

4

35 45 55 65 75

TiO2

SiO2

0

2

4

6

8

10

12

14

35 45 55 65 75

Fe2O3t

SiO2

0

2

4

6

8

10

12

14

35 45 55 65 75

MgO

SiO2

0

2

4

6

8

10

12

14

16

35 45 55 65 75

CaO

SiO2

MI Puy Beaunit (J et al '05)

CP-Bas-H (V et al., 1981)

CP M-T (V et al., 1981)

Montcineyre

Montchal

Pavin bomb

Clierzou

Gdm CP

Glass KBP

Glass 81P1

Fig. 7.1 Evolution of major element compositions (wt%) of Pavin
group magmas. Black dot : Montcineyre basalt (lava fl ow); circled grey
dot : Montchal hawaïite (lava fl ow); dashed circles : Pavin benmoreites
(bombs). Triangles : glass compositions of Pavin benmoreite ( open tri-
angles bombs (KBP), solid triangle : residual glass of amphibole
cumulates(81P1)). Light grey dots : compositions of Chaîne des Puys
(stricto sensu) magmas (Bas-H: basalts- hawaïites, M-T: mugearites-

trachytes; Villemant et al. 1981 and unpublished data). Light grey

crosses : glass compositions of Chaîne des Puys (stricto sensu) samples

(data from Villemant et al. 1981 ; Lemarchand et al. 1987 ). Grey dia-

mond : amphibole-bearing trachyte of Clierzou volcano (north Chaîne

des Puys). Open squares : compositions of melt inclusion in olivine of

Puy Beaunit (north Chaîne des Puys; data from Jannot et al. 2005 )

B. Villemant et al.

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