Introduction - Origin of Potassium-rich Silica-deficient Igneous Rocks - page 5

10

MORB
W Mexico
Missouri Breaks
Sunda

Highwood Samples

5

Minettes
Mafic Phonolite
Shonkinite
Syenite
Latite

0

Vesuvius
Banda
Roccamonfina

H aystack
Butte
Winnett
Sill
Leucite
Hills

.5

Vulsini

Yogo

.10

Gaussberg

Spain

.15

Absaroka

Crazy

Mts.

.20

Smoky
Butte .25

.30

0.704 0.708 0.712 0.716 0.720

ε Nd versus Sr 87 /Sr 86 Fig. 1.4 The ratios of ultrapotassic rocks from different localities (after

O ' Brien et al. 1991)

0.700 0.710 0.720

WEST KIMBERLEY
GAUSSBERG
LEUCITE HILLS

SMOKY BUTTE

S.E.SPAIN
WESTERN ALPS
HOLSTEINSBORG
PRAIRIE CREEK
TORO ANKOLE
BATBJERG
SAN VENANZO
CUPAELLO
MT. AMIATA

RADICOFANI
VULSINI

CIMINI
VICO

SABATINI
ALBAN HILLS
ERNICI
ROCCAMONFINA
SOMMA - VESUVIUS
NEW SOUTH WALES
MORDOR
SIERRA NEVADA
NAVAJO
AFYON

Fig. 1.5 The 87 Sr/ 86 Sr ratios of K-rich rocks from different localities (after Foley et al. 1987)

fluorine content of the potassic rock series is particularly more abundant,
where the K 2 O content is much greater than the Na 2 O concentration (Foley et al.
1987; Edgar and Pizalato 1995; Edgar et al. 1994). It was also pointed out by

The