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ACTA
VULCANOLOGICA
18 · 1-2 · 2006
FABRIZIO SERRA · EDITORE
PISA · ROMA
OFFPRINT
ACTA
VULCANOLOGICA
Rivista a cura dell’Associazione Italiana di Vulcanologia (-onlus)
Journal edited by the Italian Association of Volcanology (-onlus)
79
. I
geodynamic evolution of the Mediterranean re-
gion during Miocene and Plio-Quaternary was
complex, although the general framework can be re-
ferred to the collision of Africa with continental Eu-
rope. After the formation of small oceanic basins (Al-
gerian and Provencal) in the westernmost sector of the
Mediterranean area, the westwards subduction of
Adria and Ionian plates beneath the Southern European
margin and the opening of the Tyrrhenian Sea domi-
nate the last 5 Ma. The main steps of the Central
Mediterranean evolution can be summarized as follows
(see Cavazza and Wezel 2003, and references therein;
Peccerillo 2005): a) the progressive Ewards shifting of
the compression front and the Wwards subduction re-
sulted in the formation of the Apennines orogenic
chain, b) consequent migration of magmatism in the
same direction occurred; c) progressive opening of the
Tyrrhenian Sea basin determined formation of Vavilov
and Marsili oceanic sub-basins (from ~4 Ma), while rift-
ing and intra-plate magmatism developed in Sardinia (5-
Special Issue «Acta Vulcanologica» · Vol. 8 (-2), 2006: 79-04
* Corresponding Authors: G. De Astis: e-mail: gianj@ov.ingv.it; F. Lucchi: e-mail: Federico.lucchi@unibo.it; C. A. Tranne: e-mail: claudio.tranne@
unibo.it
THE AEOLIAN VOLCANIC DISTRICT:
VOLCANISM AND MAGMATISM
G D A* · F L · C A. T
. Istituto Nazionale di Geosica e Vulcanologia, Sezione di Napoli - Osservatorio Vesuviano,
Via Diocleziano 328, I 80124 Napoli, Italy
2. Dipartimento di Scienze della Terra e Geologico-Ambientali, Università di Bologna,
Piazza Porta San Donato 1, I 40126 Bologna, Italy
A
The Aeolian Volcanic District is a geologically complex region characterised by a wide spectrum of volcanism and compositionally
variable magmatism younger than -.3 Ma. Submarine and subaerial volcanic activities formed seven large strato-volcanoes, that up-
raise from ~500-2000 m b.s.l., and several seamounts. The Aeolian volcanism is the result of the long interplaying among collision,
subduction and extension processes occurred in the Mediterranean area aected by multiple geodynamic processes. Geophysical, seis-
mological and geochemical data allow recognition of three main sectors, each characterized by remarkably similar structural, vol-
canological and compositional features. The eastern sector (including Stromboli-Panarea) is characterised by a prevailing - to
- striking fault system, deep seismicity and magmas with variable anity, from CA to KS, generally outpured through low-in-
tensity eruptions. The central sector (including Lipari, Vulcano and the younger part of Salina) is strongly aected by the presence of
the - oriented strike-slip lithospheric fault system known as ‘Tindari-Letojanni’. Eruptive activity in the central sector shows
the wider spectrum of magma compositions in the archipelago – ranging from basalts to rhyolites, with CA, HKCA, SHO and KS
anity – and the eruptions with the highest intensity and magnitude. The western sector (including the older part of Salina, Filicudi
and Alicudi) is characterized by a main - striking fault system that conditioned the development of both subaerial and sub-
marine volcanoes, basically characterized by CA to HKCA mac and intermediate magmas of subduction origin. Going from east to
west, a general increase of crust thickness (from ~7 km below Stromboli up to ~25 km below the western sector) and magma com-
position variations (with a general decrease of Sr-isotopes and an increase of Nd-, Pb-isotope and LILE/HFSE ratios) are observed.
Overall, trace elements and radiogenic isotopes signatures variations along the indicate modications in the nature and intensi-
ty of metasomatic processes occurred in the Aeolian mantle.
The eruptive history of each island is reconstructed by giving special emphasis to the chronostratigraphic role played by fossil ma-
rine conglomerates intercalated to volcanic products. Older and more primitive CA basalt to basalt-andesite volcanic products relat-
ed to strombolian and eusive volcanic activity were emplaced on Salina and Filicudi in a poorly constrained time span started around
430-400 ka. After an apparently long period of quiescence, volcanic activity started again between ~220 and 24 ka on Filicudi, Salina,
Lipari and Panarea, with the emplacement of CA basalt-andesite to andesite and dacite volcanics related to mainly strombolian and
eusive activity, with a minor role for explosive hydromagmatic eruptions. Between ~24 and 80 ka, HKCA andesitic and subordinate
dacitic volcanic products related to both explosive (mainly hydromagmatic) and eusive volcanic activity were emplaced on Lipari,
and Alicudi, whereas on Vulcano and Stromboli SHO products were erupted together with minor HKCA lavas. Starting from ~80 ka,
more evolved CA and HKCA andesitic to daci-trachytic -up to rhyolitic products were mainly erupted on Lipari and Salina and to a
lesser extent on Panarea, Alicudi and Filicudi. Most of these magmas were produced by eusive activity (mainly dome-forming) and
associated high-energy explosive eruptions. In the last 25 ka ca., a growing and intensication of the volcanism in the central sector –
probably associated to increased activity of the Tindari-Letojanni fault system – occurred; whereas volcanism ceased in the western
sector and was regular and almost continuous in the eastern one through Stromboli. At present time Vulcano, Stromboli and sub-
marine area of Panarea show active volcanic phoenomena.
K: Aeolian Volcanic District, Tyrrhenian Sea, Volcanic rock, Calc-alkaline magmas
G. De Astis et alii
80
0. Ma); d) counter-clockwise rotation of Italian Penin-
sula and Adria plate generated stretching and segmen-
tation of the Apennines through lithospheric linea-
ments (Ancona-Anzio, Ortona-Roccamonna and
Sangineto) cross-cutting the chain; e) distinct crust-
mantle domains formed along the Italian peninsula as
consequence of these geodynamic processes (F. ).
The Italian volcanism developed and progressively
shifted along a belt parallel to the Tyrrhenian Sea border,
from Corsica-Tuscany (~4-7 Ma) to Campania (~ Ma
to Present), and wards along the central part of the
Tyrrhenian Sea to the Aeolian Volcanic District ().
This migration, and the geotectonic/geodynamic
processes occurred in the last 7-8 Ma, gave rise to distinct
magmatic provinces that exhibit volcanites with dier-
ent major element composition and/or incompatible
trace element ratios and/or radiogenic isotopes signa-
tures (Peccerillo 2005, and references therein). The
(~.3 Ma to Present) is one of these magmatic provinces,
partially associated to the Campanian one, and extends
for ca. 200 km between the margin of the Calabrian
Arc and the southern border of the Marsili oceanic back-
arc basin (F. 2a). The signicance of the in the
complex geodynamics of the Southern Tyrrhenian is
still controversial, although a wealth of papers indicates
the Aeolian volcanism as related to subduction process-
es (e.g., Bàrberi et alii 973, Keller 982, Ferrari and
Manetti 993, Mantovani et alii 996, Doglio ni et alii 200
- F. 2b). The occurrence of deep-focus earthquakes de-
picting a -dipping Benio zone (Anderson and Jack-
son 987, Milano et alii 994, Selvaggi and Chiarabba
995, Frepoli et alii 996) and the presence of magmas
with typical Island Arc geochemical features (Bàrberi et
alii 974; Beccaluva et alii 982, 985; Ellam et alii 989;
Francalanci et alii 993) argued for this environment. Fur-
ther geological and magmatological studies have pro-
vided new insights on the Aeolian magmatism and its ge-
odynamic signicance in the Central Mediterranean
setting (e.g., Peccerillo 200, Calanchi et alii 2002b, De
Astis et alii 2003). By these means, Aeolian magmatism
appears to be characterized by an anomalous spatial and
temporal overlapping of the volcanic products with Is-
land Arc anity and the nal occurrence of potassic al-
kaline series (only at Vulcano and Stromboli) with geo-
chemical signature not strictly related to subduction.
Based on the compositions of mac magma erupted
from these islands during the Holocene and geophysi-
cal/structural data, some authors proposed the possible
transition of the Aeolian magmatism from subduction-
type to post-collisional/rifting type (e.g. De Astis et alii
2003). Whatever the case, many other papers evidence
wide petrological and geophysical dierences moving
from Alicudi-Filicudi Volcanoes (i.e. tipically revealing
subduction-related geochemical signatures) and Strom-
boli (i.e., potassic rocks closely similar to those from
Somma-Vesuvius for geochemistry and radiogenic iso-
topes), suggesting a geodynamic scenario for the
more complex than simple subduction. In other words,
this could mean that a remarkable change of active
geodynamic processes during time and across the
occurred, as reported by several papers dealing with
geology and/or magmatism of Southern Tyrrhenian
Sea and Southern Italy (e.g., Wang et alii 989; Westaway
993; Carminati et alii 998; Gvirtzman and Nur 999,
200; Meletti et alii 2000; De Astis et alii 2006a).
The aim of this paper is to provide a review of vol-
canic, structural and petrological data about the , a
unique and reknown volcanic region that was site of a
large variety of volcanic activities and shows active vol-
canic phoenomena on Stromboli and Vulcano Islands.
Our review has the purpose of depicting a general syn-
thetic framework of Aeolian volcanism and magma-
tism that could explain mutual interaction between the
regional geodynamic processes and tectonic regimes
locally aecting the lithosphere.
2. R G
The emplaced on 5-20 km thinned continental
crust (Piromallo and Morelli 2003) in the southern
Tyrrhenian Sea, along the margin of the Calabrian
Arc (Calabro-Peloritano basement); a thickening of the
crust is observed moving toward this Arc (~25 km be-
neath Calabria; F. ). The Calabrian Arc is a fragment
of the European plate that was aected by pre-Hercyn-
ian, Hercynian and Alpine tectonism and metamor-
phism, and shifted away from the Corsica-Sardinia
block to its present position during the opening of the
F. . Tyrrhenian Sea opening and evolution from the Lower
Miocene to Presen Time. Symbols: SA = Sardinia, Co = Corsi-
ca, Ca = Calabria, Si = Sicily.
Pliocene inferiore (5.3 - 3.4 Ma) Pre sen te
Miocene Medio (14.5 - 6 ma)Mio cen e inferiore (23.5 - 14.5 Ma )
Sa
Co
Co
Sa
m
ar
T
i
r
r
e
n
o
Si
Ca
EUROPA
ADRIA
AFRICA
Si
Ca
Rollback
Sa
Co
Si
Ca
D
ina
r
i
di
m
a
r
Adr
iatico
mar
Ionio
A
p
p
e
n
n
i
n
i
Sa
Co
Si
Ca
Tunisi
M
V
b
a
Arco magmatico attivo fronte di
subduzione attiva Sovrascorrimento Crosta oceanica
di neo-formazione
Faglie normali Faglie
trascorrenti
cd
The Aeolian Volcanic District: volcanism and magmatism
8
Tyrrhenian Sea. It extends from the southernmost part
of the Apennines to the Sicilian-Maghrebian chains and
is bounded by the Sangineto tectonic line to the and
the Tindari-Letojanni fault system to the . The base-
ment consists of a pile of nappes comprehensive of pre-
Alpine metamorphic and granitoid rocks, Mesozoic to
Tertiary sedimentary rocks, ophiolitic sequences, and
Quaternary sediments. The metamorphic rocks, often
with Alpine overprint, as well as the sedimentary se-
quences include a very large spectrum of lithologies
(Bonardi et alii 200, and references therein) that call for
wide possibilities of magma-wall rock interaction dur-
ing the upraising and evolution of Aeolian magmas.
The role of source contamination vs shallow crustal as-
similation in the genesis of their compositional charac-
teristics has been strongly debated due to the large va-
riety of magma types observed among the Aeolian
volcanic rocks and will be discussed further on.
The (F. 2c) consists of seven main volcanic is-
lands (Alicudi, Filicudi, Salina, Lipari, Vulcano, Panarea,
and Stromboli) and seven minor seamounts (Eolo,
Enarete, Sisifo to the , Lametini, Alcione, Palinuro
to the ) that form a ring-shaped structure (Beccaluva
et alii 985), around the subsiding Marsili basin (.8-0.2
Ma; Savelli 2000) and Marsili seamount (0.7 Ma-active;
Marani and Trua 2002). Volcanic activity took place en-
tirely during the Quaternary, as suggested by a series of
radiometric ages ranging from ~.3 Ma to the Present
(Beccaluva et alii 985; Gillot 987; De Rosa et alii 2003,
and references therein). The oldest volcanic rocks are
located in the western portion of the (Sisifo
seamount: .3 to 0.9 Ma; Eolo seamount: 0.85 to 0.66
Ma; Enarete seamount: 0.78 to 0.67 Ma), whereas
younger samples are from its eastern edge (Palinuro
seamount: 0.35 Ma; submarine Stromboli Volcano: 0.53
to 0.8 Ma). Between the and the on-land outcrops
of the Calabrian Arc, Pleistocene elongated sedimenta-
ry basins occur (Gioia and Paola basins). They formed
during the still active extensional tectonic phase that af-
fected the Calabrian Arc and eastern Sicily from about
0.7 Ma (Monaco et alii 997).
The seven volcanic islands (F. 2c) represent the
emersed tips of mainly submerged stratovolcanoes up-
raising from 500-2000 m b.s.l. and their oldest radio-
metric ages are from Salina (~0.43 Ma; De Rosa et alii
2003, and references therein); a Ar/Ar age of .02
Ma reported by Santo et alii (995) for Filicudi lowest
rocks is still debated. Geo-morphological and structur-
al data (e.g., Bàrberi et alii 994, Favalli et alii 2005) indi-
cate that: a) Panarea and Stromboli belong to the same
volcanic complex extending for more than 45 km along
- direction and are separated by a ,200 m deep
saddle; b) Vulcano-Lipari and Salina form a - elon-
gated ridge, emplaced along the horst and graben sys-
tem related to the Tindari-Letojanni shear zone togeth-
er with several small submarine centres; c) Alicudi and
Filicudi disposed along a - direction, form the small-
est edices of the ; they are associated both to a
- aligned submarine volcanic centes and sepa-
rated by an extended, at saddle b.s.l. Generally, the Ae-
F. 2. a) Bathymetric map of Southern Tyrrhenian Sea with the
seamounts distribution (from Sisifo to the , up to Palinuro to
the of the ) and the Aeolian archipelago, which form the
ring-shaped architecture of the Aeolian Volcanic District; the po-
sition of the Tindari-Letojanni tectonic system ( system),
which extends to Malta escarpment and presently represents a
tear fault acting along the eastern border of the Ionian slab, is re-
ported. b) - simplied section along the southeastern sec-
tor of the Tyrrhenian Sea where is synthesized the subduction
process aecting the region: an ongoing roll-back process of the
Ionian slab (Gvirtzman and Nur 999, 200) is widely accepted to
depict the present geodynamic of the region. c) Structural
scheme of the reporting the main fault systems.
volcanic
island
volcanic
edifice
seamount
smt
Aeolian Volcanic
District
Panarea
Lipari
Filicudi
Alicudi
Vulcano
Stromboli
Salina
Aeolian Arc
Panarea
Lipari
Filicudi
Alicudi
Vulcano
Stromboli
Salina
Aeolian Arc
Eolo smt
Enarete smt
Sisifo smt
Lametini smt
Alcione smt
Palinuro smt
Marsili smt
Glauco smt Tyrrhenian
abyssal plain
Eolo smt
Enarete smt
Sisifo smt
Lametini smt
Alcione smt
Palinuro smt
Marsili smt
Glauco smt Tyrrhenian
abyssal plain
1000
2000
3000
1500
2500
2000
2500
2500
3000
1000
2000
1000
1500
1500
1500
1000
1500
1000
15∞
30I E
38∞30I
14∞30I E
38∞70I
C
A
L
A
B
R
I
A
SIC
I
L
Y
TAORMINA FAU LT
SISIFO FAULT
FILICUDI FAULT
MILAZZO FAU LT
C.VATICANO FAULT
CATANZARO FAULT
TINDARI LETOJANNI
FAULT
SIC
I
L
Y
050
Km
40302010
N
volcanic island
volcanic edifice
downthrow
direction
strike-slip
component
a
c
Km 200
100
astenosphere
Ionian Sea
αβ
I
o
n
i
a
n
p
l
a
t
e
l
i
t
h
o
s
p
h
e
r
e
a
s
t
h
e
n
o
s
p
h
e
re
Tyrrhenian Sea Calabria
T
yr
r
h
e
n
i
a
nplat
e
b
050
Km
0250
Km
T
y
rr
h
e
n
i
a
n
A
d
r
iaticSe
a
I
T
A
L
Y
I
o
n
i
a
n
S
e
a
S
e
a
Me
d
it
e
r
r
an
e
a
n
S
e
a
12∞ E16∞ E8∞ E
38∞
42∞
46∞
α
β
TL
System
G. De Astis et alii
82
olian Islands are characterised by composite structures
due to the superposition in time and space of multiple
vents and to recurrent volcano-tectonic activity (sector
collapses occurred at Alicudi, Filicudi, Salina, Strom-
boli). Notheworthy, islands of the central sector – Vul-
cano, Lipari and partly Salina – display an early forma-
tion of stratovolcanoes, dissected by calderas or
multiphase sector collapses and nal growing of domes
or tu cones. Geology and petrology of their subma-
rine portions are still poorly known (detailed informa-
tion is limited to the proximal oshore sectors – e.g.,
Romagnoli et alii 993, Gamberi 200) whereas the
emergent portions of the volcanoes are far better
known (see further paragraphs). Recent geomorpho-
logical studies at larger scale, reporting the general fea-
tures of the sea oor topography that surrounds the Ae-
olian Islands, have been performed by Favalli et alii
(2005).
Nowadays, active volcanism is represented by fu-
maroles, hot springs and shallow seismicity that charac-
terize wide submarine and on-land areas of the central
and eastern sectors of the . In particular, historical
and present volcanic activity are reported for: i. Lipari
( ) and Vulcano Islands (888-890 ; with ongo-
ing intense fumarolic activity from La Fossa cone; ii.
Stromboli (nearly persistent activity during the last
~2,000 years with recent paroxysms in 996, 2003 and
2005); iii. submarine areas around Panarea (strong sub-
acqueous gas emissions during 2002) and the eastern
seamounts (Soloviev et alii 990, Gamberi et alii 997).
3. G-
The geological evolution of the Aeolian Volcanoes
occurred during successive eruptive epochs (periods of
volcanic activity characterized by specic location of
eruptive centres, eruptive style or petrological and geo-
chemical features; sensu Fisher and Schminke 984) that
are subdivided by main unconformities formed during
volcano-tectonic events or major quiescent stages when
erosional and reworking processes in subaerial and ma-
rine environment became prevalent. In this respect, re-
cent eld data (e.g. Lucchi et alii 2004a) suggest that edi-
cation and dismantling of the Aeolian Volcanoes were
strongly conditioned by the interaction between vol-
canic activity and late Quaternary sea level uctuations.
This interaction caused the formation of staircased ma-
rine terraces outcropping along the coastal slopes of the
Aeolian Islands and intercalated to their volcanic prod-
ucts (e.g., Keller 967, 980a; Lucchi 2000; Lucchi et alii
2007, and references therein). Figure 3 resumes the dif-
ferent phases of this interaction. The terraces better con-
strained are those related to marine paleo-shorelines due
to the last interglacial sea-level peaks corresponding to
marine oxygen-isotope stages (MIS) 5e, 5c and 5a. These
paleo-shorelines are visible and correlated in most of the
Aeolian archipelago, i.e. the Islands of Lipari, Filicudi,
Panarea, Salina and Alicudi, whereas paleo-shorelines of
generic pre-MIS 5 age have been identied on Filicudi
and Salina Islands, and MIS 3 paleo-shorelines are likely
to occur on Panarea Island. As a consequence of their
wide diusion, marine terraces attributed to MIS 5 as-
sume an important stratigraphic role not only for single
volcanic edices but also with the purpose of dening
correlations on a regional, inter-island scale. The
detailed reconstruction of stratigraphic relationships
between marine terraced deposits and volcanic rocks
allows two main stratigraphic unconformities to be
dened and correlated at a regional scale (UIand UII;
Tranne et alii 2002b; Lucchi et alii 2003). Noteworthy,
those unconformities can be recognized also on islands
where marine deposits are not present on the basis of
detailed stratigraphy and radiometric dating of volcanic
rocks (e.g. on Vulcano - De Astis et alii 2006b). As a
whole, the UIand UII unconformities provide a regional
F. 3. Schematic block diagram illustrating the geological evo-
lution of Aeolian Islands in terms of eruptive epochs, identied
during the evolutionary stages pre- and Crotoniano and pre-, sin-
and post-Tirreniano. Eustatic curve from Waelbroeck et alii 2002.
(metres bsl)
MIS 3
?
?
Eustatic Curves Alicudi
(
4 )
Filicudi
( 8 )
Salina
( 3, 4 )
Lipari
( 7 )
Stromboli
( 2, 4 )
Age
(ka)
Panarea
( 5, 6 )
Vulcano
( 1 )
Waelbroeck et al., 2002
Chappell and Shackleton, 1986
A5
A4
A1 A2
A3
F5
F6
F4
F1
F2
F3
Sa4
Sa5
Sa6
Sa1
Sa2
L1
L2
L4
L5
L6
L3
P6b
P6a
P6c
P5
P1
P2
P3
P4
V1
V2
V3
V4
V5
V6
V7
St1
St2
St3
St4
St5
St6
Sa3
SYMBOLS
Ischia Tephra (56 ka)
it
external
tephras
M. Guardia pyr. (22-20 ka)
inter-island
tephras
vg
gu
lpt
gpt
V. del Gabellotto pyr. (11-8 ka)
Lower Pollara Tuffs (ca. 22 ka)
Grey Porri Tuffs (67-70 ka)
mp
M. Pilato pyroclastics (1.4 ka)
pt
Petrazza Tuffs (75-77 ka)
X5
X5 tephra (ca. 105 ka)
X6 tephra (ca. 110 ka)
X6
Sal-III
Sal-III tephra (ca. 73 ka)
Sal-IV
Y5
Y5 tephra (39 ka)
Sal-IV tephra (ca. 68 ka)
T
EPHROCHRONOLOGY
E
RUPTIVE
E
POCHS
not well age-constrained
periods of eruptive activity
intervals of eruptive activity
marine erosion surface
subaerial erosion surface
tectonic collapse
U
NCONFORMITIES
F3
Sa2
bt
150
100
50
124
80
200
350
400
300
break
X6
X5
pt
gpt
it
lpt gu
vg
mp
Sal-III
Sal-IV
0
-100 -50
MIS 5e
MIS 5c
MIS 2
MIS 1
MIS 6
MIS 5a
pre-MIS 5 marine deposits
pre-MIS 5 marine deposits
marine terrace I
marine terrace I
b
marine terrace II
marine terrace III
MIS 7
MIS 9
MIS 11
MIS 10
The Aeolian Volcanic District: volcanism and magmatism
83
stratigraphic framework that makes possible a synthesis
of the geological evolution of the Aeolian Volcanoes ac-
cording to three dierent main stages: stage > 24 ka
(before MIS 5), 2 stage between 24-8 ka (during MIS
5); 3 stage < 8 ka (after MIS 5). Within this strati-
graphic framework, accurate tephrostratigraphy stud-
ies have provided signicant constraints on a regional
scale that are useful to bracket the volcanism of the Ae-
olian Islands. The occurrence of inter-island tephras,
which are related to high-explosive eruptions of the Ae-
olian Volcanoes, and distal tephras, which are the result
of eruptive events from external sources (e.g. Campan-
ian area), has been documented (F. 3, inbox). More-
over, the Mt. Guardia pyroclastics from Lipari (dated be-
tween 22 and 20 ka; Tranne et alii 2002a) and the widely
known Ischia-tephra (dated at 56 ka - Kraml 997) repre-
sent further signicant chrono-stratigraphic marker
beds, widespread on most of the islands (F. 3). Fur-
thermore, a pyroclastic succession made of ashy brown
layers emplaced from ~80 to 5 ka, which constitutes the
so-called Brown Tus deposit and crop out all over the Ae-
olian archipelago (up to Capo Milazzo peninsula) has
been recently outlined as stratigraphic markers of re-
gional importance (Lucchi et alii, submitted). At least
part of this succession, that younger than Ischia-tephra,
seems to be related to vent(s) located in the area of La
Fossa Caldera on Vulcano (De Astis et alii 997a; Lucchi
et alii, submitted), as is testied by eld correlation glass
compositions, and the variation of isopachs and grain-
size in the deposits outcropping on Vulcano, Lipari and
Salina.
4. P D
The compositions of the rocks display a large
range of potassium content: from arc-tholeiitic (Lame-
tini seamount and southern margin of Marsili basin)
and calc-alkaline (CA), to shoshonitic (SHO) and K-al-
kaline (KS) suites (e.g., Ellam et alii 989; Francalanci et
alii 993; Peccerillo 2005, and references therein - Fig.
4). Rocks from the huge Marsili seamount range from
CA basalts to HKCA andesites, as most of the other
seamounts; SHO rocks have been dredged on the west-
ern seamounts and the northern slope of Stromboli.
Overall, petro-chemical features of both seamounts
and islands products are similar, with lavas showing
porphyritic textures: commonly, phenocrysts of pla-
gioclase, clinopyroxene, Ti-Fe oxides set in a matrix
made of similar phases and variable amount of glass;
subordinately, olivine and orthopyroxene could be
found in the mac-intermediate rocks or K-feldspar, bi-
otite, and horneblende in the evolved ones. Presence of
xeno crysts sometimes occurs, with the most famous
example represented by some Lipari andesites (lava
containing sillimanite, cordierite, corundum, garnet,
etc.). The degree of magma evolution is also highly
F. 4. KO vs SiOclassication diagram (Peccerillo and Taylor 976) for the Aeolian Island rocks and Marsili seamounts. Data Source:
Calanchi et alii 2002, De Astis et alii 997b, Del Moro et alii 998, Ellam et alii 989, Esperanca et alii 992, Francalanci et alii 989, Ger-
tisser and Keller 2000, Hornig-Kjarsgaard et alii 993, Pappalardo et alii 999, Peccerillo and Wu 992, Peccerillo et alii 993, Peccerillo
2005, Santo 2000, Trua et alii 2004.
48 52 56 60 64 68 72 76
0
2
4
6
8
K2O
SiO2
Latites
Shoshonites
Trachytes
Rhyolites
Shoshonitic
Basalts
SHO
HKCA
CA
TH
Marsili
seamount
High-K Dacites
Andes.
Basalts
Legend
Vulcano Alicudi
Lipari Filicudi
Salina
Legend
Panarea
Stromboli
Dacites
G. De Astis et alii
84
variable and range from basalt to alkali-trachytes and
rhyolites, with the rhyolitic lava and the evolved pyro-
clastic rocks often characterized by poorly porphyritic
to aphyric textures. Overall, Aeolian magmas reveal
quite complex variations in the major, trace element
and isotopic compositions, measured both within the
single island and along the archipelago. In general,
merging of mineralogical, geochemical and uid in-
clusion data indicate that Aeolian magmas frequently
underwent to polybaric ponding and evolution. Such a
processes are able to explain part of their composition-
al variations and radiogenic isotope ranges. On the oth-
er hand, the variable geochemical and isotopic signa-
tures recorded in the mac rocks (MgO > 4% - e.g.,
De Astis et alii 2000; Peccerillo 2005, and references
therein) reveal dierent source imprinting and evi-
dence along-arc compositional variations that require
regional changes in the physico-chemical conditions
leading the magma genesis (mineralogy and features of
pre-metasomatic mantle, nature and degree of mantle
metasomatism, uids vs melts inuence, degrees of
partial melting). Going from east to west, volcanic
rocks display a general decrease of Sr-isotopes and an
increase of Nd, Pb and He isotope and LILE/HFSE ra-
tios, with the most isotopically primitive rocks found at
Alicudi. For what concerns the presence of dierent
magma suites (i.e. variable degree of KO enrichment)
regional variations are more complex. Magmas from
eastern islands vary from mac to silicic, even if the
most evolved rocks from Stromboli are dacites or tra-
chites, and display a large range of potassium contents
(CA, HKCA, SHO and KS; F. 4). By contrast the an-
ity of volcanic rocks from western sector is typically
CA (or HKCA), with dominance of mac and inter-
mediate compositions (F. 4; Alicudi and Filicudi).
Rocks from Vulcano-Lipari-Salina reveal both highly
variable degrees of magma evolution (from basalts to
rhyolites) and KO enrichment (from CA to KS), with
very wide variations related to Vulcano magmas (F.
4). Therefore, it is possible to say that from to a sig-
nicant petrological variability exists. Although a reli-
able knowledge of the submarine rocks geochemistry
doesnot exist due to few data available (with the ex-
ception of Marsili seamount: Trua et alii 2004), it seems
that the anity and compositional features of Aeolian
seamounts does not follow the pattern drawn by the is-
lands (Peccerillo 2005). Other compositional variations
among the volcanics outcropping on the islands are
time-related (De Astis et alii 2003): . products from the
eastern and central sectors (i.e., Stromboli and Vul-
cano) show a progressive transition of magma anity
from CA-HKCA to SHO and KS in the last 30-40 ka; 2.
appearance of felsic products occur at 40-50 ka, mainly
in the central sector, where the rocks display the wider
SiOrange. By contrast, magmas of the western sector
do not show these transitions, erupting only CA and
HKCA products of mac-intermediate compositions
for their whole eruptive history (Manetti et alii 995a,
995b; Santo 2000). Figure 5 shows and resumes these
time-related variations.
For what concerns the progressive transition to more
potassic magmas – although magmas presently erupted
at Stromboli have HKCA anity (F. 5a) and therefore
still indicate a coexistence in the Aeolian archipelago of
CA and KS suites – petrological studies on mac rocks
indicate a clear role for the mantle source(s) and
processes (e.g., Ellam et alii 988, 989; De Astis et alii
997b, 2000; Santo 2000; Peccerillo 2005). In other
words, these studies provided evidence that mac mag-
mas with dierent potassium contents reect primary
compositions inherited from a heterogeneous mantle
source.
The increasing occurrence of dacitic, trachytic and
rhyolitic rocks is related to the progressive formation of
shallower reservoirs, within the upper crust, where sig-
nicant volumes of mac-intermediate magmas pond-
ed and dierentiated (e.g., Gioncada et alii 2003; Zanon
et alii 2003, and references therein). Noteworthy, the ap-
pearance of the evolved magmas produced both extru-
sive and high-energy explosive activities: rhyolitic
domes formed on Vulcano, Lipari and Panarea between
54 and 8 ka (Gabbianelli et alii 990, Tranne et alii 2002a,
De Astis et alii, 2006b); while subplinian or high-explo-
sive eruptions, involving minor magma volumes, oc-
curred on Salina (24 ka, Pollara event - Calanchi et alii
993), Lipari (Mt. Guardia eruptions, 24-22 ka - Crisci et
alii 98), and Vulcano between 4 and 8 ka (La Fossa
Caldera - De Astis et alii 997a).
The degree of evolution observed in the Aeolian
magmas and/or their high radiogenic compositions to-
gether with the variety of metamorphic and igneous
xenoliths, (with rare ultramac types) found in the
Aeolian volcanics indicate that magma-crust interac-
tion – during the magma ponding or ascent to the sur-
face – can occur. Metamorphic xenoliths are usually
more abundant in the mac rocks than in the andesites
(e.g., Frezzotti et alii 2003; Peccerillo 2005, and refer-
ences therein) and consist of quartz-rich rocks (some-
times showing glass lms along grain boundaries) and
a few biotite gneiss and granulites. Igneous xenoliths in-
clude gabbros, diorites, granites and a few ultramac in-
clusions (made up of clinopyroxene and olivine) that
represent fragments of the Hercynian granitoids, rep-
resenting the intrusive equivalents of volcanic rocks or
cumulate lithologies. Therefore, by means of the geo-
chemical and isotopic xenoliths compositions, a wealth
of papers demonstrate that interaction between mac-
intermediate melts and the rocks forming the crustal
basement of Calabrian Arc (magma contamination)
can sometimes explain the degree of dierentiation and
radiogenic signatures of the magmas uprising in Aeo-
lian central sector (Esperanca et alii 992, De Astis et alii
997b, Del Moro et alii 998). Contamination by crustal
material also played an important role in the evolution
of magmas from the eastern sector (Calanchi et alii
2002, Renzulli et alii 200). Sr-Nd-Pb isotope variations
in the volcanics investigated require the involvement of
crustal material both from lower and upper crust, and
roles for (Assimilation Fractional Crystallization),
(Assimilation Equilibrium Crystallization) and
The Aeolian Volcanic District: volcanism and magmatism
85
(Replenishment, Fractionation, Tapping, Assimi-
lation) processes occurring at dierent depths and vari-
able extent in the Aeolian mantle-crust domain (e.g.,
Francalanci et alii 989, De Astis et alii 997b, Del Moro
et alii 998, Peccerillo et alii 2004).
More detailed petrological data will be reported in
the paragraph dedicated to each island.
5. G S D
For many years the Aeolian Volcanoes have been inter-
preted as a ‘classic’ volcanic arc formed through the sub-
duction of the Ionian micro-plate, consequent to the
broad collision of African and European plates (e.g., Bàr-
beri et alii 974, Gasparini et alii 982, Keller 982, An-
derson and Jackson 987). In the early studies on earth-
quakes distribution in the Southern Tyrrhenian Sea
(Caputo et alii 970; Giardini and Velonà 99, and refer-
ences therein), a Benio zone dipping 50° or 60° be-
neath the Calabrian Arc was one of the decisive feature
identied by geophysics, which pointed to subduction
occurrence. Controversial interpretation were provided
on its shape and continuity for a couple of decades due
to paucity of available seismic data, but a detailed study
by Giardini and Velonà (99) nally indicated that the
subducting lithospheric slab is continuous down to
~500 km and the previously suggested curvature is ab-
sent. Most recent geophysical studies (Milano et alii
994; Chiarabba et alii 2005, and references therein),
which report data of deep seismicity (up to 550 km), in-
dicate that the process of active subduction of the Ion-
ian slab ( dipping, with a lateral continuity of ca. 200
km) is limited to the region of the Tindari-Letojanni
strike-slip fault system and, therefore, it involves only
the eastern sector of the Aeolian archipelago (F. 2c).
By contrast, central and western sectors of the
don’t reveal intermediate and deep seismicity but only
crustal events (< 35 km, mostly in the upper 20 km- Neri
et alii 2002, Chiarabba et alii 2005) so that no seismic ev-
idence of ongoing subduction processes is available.
The 978 earthquake (M = 5.5-5.6), which occurred a
few kilometers south of Vulcano, produced - striking
cracks with en echelon arrangement associated to dex-
tral movements along the - striking shear zone
(Ventura 994). Stress tensor computation performed
for the M < 5 seismic events occurred in the central sec-
tor of is consistent with a - striking com-
pression and an - striking extension (Neri et alii
996). A few crustal earthquakes occurred in the eastern
sector are focussed along a - fault system.
F. 5. a) KO vs Age variation diagram (rocks with MgO > 4%) showing the dierent alkaline character of the magmas from dier-
ent islands (sectors); notheworthy, most recent and Present Stromboli rocks represent magmas with lower potassium contents; b) SiO
vs Age variation diagram (modied from De Astis et alii 2003): magmas from Central sector display the wider SiO range in the last
40 ka, whereas magmas from western sector never exceed SiOcontents > 63%; products older than 250 ka (basaltic andesites) are
not reported. Data Source as in Figure 4.
0 50 100 150 200 250
46
50
54
58
62
66
70
74
78
SiO2
Age (ka)
Central Sector
Vulcano - Lipari
Salina
(430 ka to Present)
Western Sector
Alicudi - Filicudi
1-0.4 Ma (?) to 28 ka
Eastern Sector
Stromboli - Panarea
(150 ka to Present)
b
1 10 100 1000
0
2
4
6
K2O
Age (ka)
Legend
Alicudi
Filicudi
Salina
Lipari
Vulcano
Panarea
Stromboli
Rocks with MgO > 4 wt.%
a
G. De Astis et alii
86
Other geophysical studies in the Southern Tyrrhen-
ian Sea have recorded further interesting data: . a belt
of gravimetric lows to the east of the Calabrian Penin-
sula, likely related to the formation of an accretionary
wedge of subducting Ionian crust against that Peninsu-
la; 2. the presence of a broad low velocity zone in the
upper mantle below the central-eastern (De Luca
et alii 997, Di Stefano et alii 999) associated to anom-
alous high heat ow (> 00 mW/m2 - Wang et alii 989;
Pasquale et alii 999), which are consistent with an up-
rising of the isotherms below these sectors of the dis-
trict. Moreover, recent data (e.g., Hollestein et alii
2003; D’Agostino and Selvaggi 2004; Serpelloni et alii
2005, 2007) reveal a dierent deformational pattern be-
tween the western and eastern portions of the (see
Esposito 2006 for a review). Evidence from geodetic
and geological investigations apparently suggest a gen-
eral long-term uplift of the , estimating a rate ~0,34
m/ka starting from the last interglacial, with the excep-
tion of Stromboli, Vulcano and Panarea (Lucchi et alii
2000, 2007). Overall, geophysical data point to depict
the as a domain with variable geological features
moving along the archipelago from to .
On-land tectonic structures and alignments of vol-
canic centres also reveal multiple regional fault systems
and remarkable changes moving along the (Locar-
di and Nappi 979, Gabbianelli et alii 990, Calanchi et
alii 993, Manetti et alii 995, Mazzuoli et alii 995, Lan-
zafame and Bousquet 997, Ventura et alii 999, Tibaldi
200; F. 2c): . a - striking fault system char-
acterises the Filicudi and Alicudi areas and shows mor-
phological features (scarps) consistent with dip-slip
movements related to a - extension (poorly con-
strained). 2. a - striking fault system (Tindari-
Letojanni system, hereafter ) aects the Lipari-Vul-
cano-Salina alignment and the fault slip data indicate
structures with dextral to oblique (right-lateral and nor-
mal) movements; the 3 islands also show two II order
tectonic systems with - e - strikes, which are ten-
sional structures associated to the shear zone. 3. a -
to - striking fault system aects the Panarea-
Stromboli sector, and shows normal movements;
minor -, - and - are also present.
In such a complex setting, geophysical and structural
data (see the references reported above in the para-
graph and De Astis et alii 2003 for a review) can be re-
drawn through a subdivision of the into three main
sectors:
i. the western sector, extending from Glauco sea -
mount to Alicudi and Filicudi Islands together with the
oldest part of Salina Island;
ii. the central sector, including the Lipari and Vulcano
Islands and the youngest part of Salina Island;
iii. the eastern sector, extending from Panarea and
Stromboli Islands to Alcione and Palinuro seamounts.
Therefore, in order to provide a reliable volcanologi-
cal and geodymamic setting for the , in the follow-
ing paragraphs we present the main events and mag-
matic phases occurred during the various eruptive
epochs, with reference to the general subdivision of the
in these three sectors. In addition to the processes
related to the sea level uctuations, we recall that the
geological evolution of the Aeolian Volcanoes was
strongly led by regional and local fault domains, in their
turn conditioned by the spatial variations in the crust-
mantle system observed along the . The dierent
interplay of these factors in each sector was nally re-
sponsible in controlling the way of magma upraising to
the surface and in conditioning the styles of eruptive ac-
tivities and their changing during time.
6. V M
6. .
avd
- western sector (Alicudi-Filicudi-Older Salina)
Volcanism in the western sector – presently inactive –
developed from ~.3-0.9 Ma that are the oldest ages
measured in the entire on volcanic rocks from Sisi-
fo seamount (Beccaluva et alii 985). The western sector
includes the Islands of Alicudi (20-28 ka) and Filicudi
(~400-56 ka) and the older portion of Salina (ca. 430-24
ka). They mostly developed along the - striking
‘Sisifo-Alicudi’ fault system, where most of the present
crustal earthquakes are focussed. Analysis of the ongo-
ing stress (see De Astis et alii 2003) along this structural
system indicates a compressive strain regime and this is
the main reason for the present-day lack of volcanism
in the western sector, where the Moho depth is ~25 km
(Ventura et alii 999, and references therein) and no low-
velocity zones in the upper mantle are present (De Lu-
ca et alii 997). Most of the volcanic rocks erupted here
are CA to HKCA mac and intermediate lavas, with
subordinate pyroclastic products; products of acid com-
positions are absent. Most of the data available for the
older part of Salina (magma anity, vents distribution,
eruptive styles) indicate a strong anity with Filicudi
and Alicudi Islands. However, as it lies at the intersec-
tion between the Alicudi-Filicudi alignment and the
fault system, it also shares several characteristics with is-
lands of the central sector (i.e. Lipari) especially for its
younger portions. Therefore it will be discussed in the
next paragraph (6. 2.).
6. . . Alicudi
The Island of Alicudi (675 m a.s.l.) is the emerged sum-
mit of a fairly regular cone-shaped stratocone, which
rises from a depth of about ,300 m b.s.l. (F. 6). Re-
cent geomorphological studies based on data, have
roughly recognised a group of never described, small-
scale seamounts to the of the edice and a double-
stepped abrasion platform around most of the island,
but missing to the east, possibly due to tectonic activity
(Favalli et alii 2005). Its morphology suggests a devel-
opment due to central volcanic activity, although recent
geological and geomorphological investigations show a
slight migration of the feeding conduit from the west-
ern side to the present summit of the volcano. Its for-
mation occurred during ve distinct eruptive epochs
subdivided by quiescent stages and three successive
volcano-tectonic collapses (unpublished data-Lucchi
The Aeolian Volcanic District: volcanism and magmatism
87
2000). This short reconstruction is a further step in the
knowledge of Alicudi geological evolution, improving
that proposed by previous studies (Manetti et alii 989,
995). The initial four eruptive epochs developed in the
range between 20-0 ka (Gillot and Villari 980, Ca-
paldi et alii 985) to late MIS 5 (00-8 ka; Lucchi et alii
2004) and determined the construction of most of the
Alicudi stratocone through the emplacement of CA
basaltic and basalt-andesitic lavas and minor pyroclastic
products (during MIS 5 evolutionary stage). High-K an-
desitic lava ows and domes were eused from the
summit crater during the last eruptive epoch (~28 ka;
Gillot 987) and owed along the southern ank of the
volcano (post MIS 5). As a whole, volcanic products ex-
hibit a restricted compositional range (from basalts to
high-K andesite) and display the most primitive petro-
logical and geochemical characteristics over the entire
Aeolian archipelago: high Mg-number (up to 72), Ni
and Cr (up to 50 and 750 ppm, respectively), lowest Sr
isotope and most radiogenic Nd isotope compositions
(Peccerillo and Wu 992, Peccerillo et alii 993).
6. . 2. Filicudi
The Island of Filicudi (739 m a.s.l.) is the emergent por-
tion of a - elongated mainly submarine volcanic
apparatus rising from the depth of about ,300 m b.s.l.
formed by multiple and partially overlapping eruptive
centres showing a signicant -wards migration in-
volving both submarine and subaerial portions (Ca -
lanchi et alii 995, Tranne et alii 2002b; Fig. 7). Ar/Ar
radiometric measures by Santo et alii (995) indicate
that subaerial development of Filicudi Island started be-
fore .02 Ma, although more recent geological investi-
gations and radiometric data suggest younger ages for
the oldest products (ca. 400 ka - Tranne et alii, 2002b).
The volcanic history of Filicudi is described by six suc-
cessive eruptive epochs (Tranne et alii 2002b) subdivid-
ed by periods of volcanic dormancy and by marine ter-
races attributed to the last interglacial (MIS 5) and to a
generic pre-MIS 5 age (possibly MIS7/9). On this basis,
the suggested reconstruction is basically dierent from
that recently proposed by Manetti et alii (995) which
was exclusively focused on the role played by volcanic
products. The oldest pre-MIS 9/, CA basaltic to basalt-
andesitic lavas (dated at ca. 400 ka) outcrop in the
sector of the island (rst and second eruptive epochs).
Then the emplacement of CA and HKCA, basaltic to
dacitic lavas and scoriae during the third to fth erup-
tive epochs (dated from 250 to 65 ka; Santo et alii 995,
Gillot 987) that determined the building of Fossa Felci
and Chiumento stratocones and Capo Graziano dome
F. 6. Geological sketch map of Alicudi Island, drawn according to distinct and successive eruptive epochs.
W
W
W
W
W
LEGEND
post-MIS 5
sin-MIS 5
SYMBOLS
crater rim
scoria cone
(or autoclastic lava cone)
lava flow
parasitic vent
neck
couleé
minor tuff cone
volcanic come
eruptive fissure
dome flow foliation
morpho-tectonic depression
caldera rim
recent landslide scar
a) fault
b) tectonic lineament
pit crater
sector collapse rim
strike-slip faults
recent continental deposits
quoted points (in metres asl)
paleo-shoreline III
1. ERUPTIVE EPOCH
2. ERUPTIVE EPOCH
3. ERUPTIVE EPOCH
5. ERUPTIVE EPOCH
Brown Tuffs
4. ERUPTIVE EPOCH
dike
plug dome
submerged volcanic body
recent fumaroles
(at Panarea)
fumarole
marine terrace inner margin
fossils
675.33
505.0
485.0
306.0
73.0
481.04
Filo dell’Arpa
Alicudi
Porto
Perciato
Montagna
Punta
di Malopasso
Mo
ntag
no
le
Di
ritt
us
u
Sc
ia
ra
tello
Pian
od
iM
andra
B
a
z
z
i
na
S
p
a
n
o
1:35000
Scale
01 Km
N
1
2
3
4
5b
5a
1
2
3
4
4
4
4
5a
5b
ab
G. De Astis et alii
88
(pre-MIS 5 stage). After the formation of MIS 5 marine
terraced deposits, the sixth eruptive epoch determined
the emplacement of the CA dacitic M. Montagnola
dome and pyroclastic products (between ca. 80 and 56
ka - Tranne et alii 2002b), which are considered the most
recent local volcanic products on Filicudi. On this sub-
ject, we give poor geological signicance to the 40±40
ka age measured for lavas of the Canna Islet by Santo et
alii (995) on the basis of high analitical error of the
measure and geological considerations (recentmost
products outcrop in the portion of Filicudi). As a
whole, volcanic rocks on Filicudi exhibit compositions
similar to those of Alicudi with a restricted range (from
basalts to dacites) and almost entirely CA anity (San-
to et alii 2004).
6. 2.
avd
- Central sector (Salina-Lipari-Vulcano)
Volcanism here has been ruled by the - orient-
ed, strike-slip TL system, along which the spatial distri-
bution of the present earthquakes clusters. The main
shear-zone runs from Salina to the mainland Sicily and
basically represents the northern tip of the regional
lithospheric discontinuity called Malta escarpment,
which cross-cutts the Sicily. De Astis et alii (2003) rec-
ognize in the fault system the major discontinuity of
the Aeolian Islands, while the - Sisifo-Alicudi
and - fault systems represent second-order struc-
tures. The fault arrangement and the present-day strain
eld should resemble that found at the termination of
strike-slip faults, where a compressive strain and an ex-
tensional strain develop on the two sides of the fault-tip
area. The Vulcano-Lipari-Salina ridge and some small
submarine volcanoes lie within a graben-like structure
that lowered the crystalline basement down to depths
of 3-3.6 km (Bàrberi et alii 994) and is - orient-
ed; along the strike of this fault system, to the of Li-
pari, a series of submarine volcanic centres are aligned.
Vulcano and Lipari lie on a continental crust thinner
(Moho ~20-2 km) when compared with that of the
western sector, which overlies a very soft upper mantle
(average of Vs ~3.85 km/s - Panza et alii 2007). On the
basis of anomalous high heat ow records (> 00
mW/m), an upwelling of the isotherms has proposed
by Wang et alii (989) and Pasquale et alii (999) for the
central (and especially eastern) sector. Volcanism in the
central sector of the was either eusive or explo-
sive, with dierent degrees of magnitude and intensity.
Volcanism displays very dierent ages becoming
younger from Salina (430-3 ka) to Lipari (~220 ka- 580
) and Vulcano (~30 ka to Present). Lipari and Vul-
cano Islands show complex and mutual overlapping in
their geological evolution, at least in the last 70 ka.
These islands erupted a wide spectrum of magma
compositions, ranging from mac to silicic, with CA,
HKCA, SHO and KS anity. Mac rocks dominate dur-
ing early evolutionary stages, whereas abundant inter-
mediate to rhyolitic pyroclastics and lavas were emitted
during the last 20 ka. Last eruptions occurred at ca. 3
ka on Salina Island, at 580 on Lipari, and at 888-890
on Vulcano.
6. 2. . Salina
Salina Island is the emerged portions of a broad
mainly submarine --oriented volcanic ridge (in-
cluding also Vulcano and Lipari volcanic edices) which
rises from a depth of about ,000 m b.s.l. (Gabbianelli et
alii 99) and transversely intersects the arc (from Alicu-
di to Stromboli). Following Keller 980a, Salina Island is
F. 7. Geological sketch map of Filicudi Island, drawn according to distinct and successive eruptive epochs.
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
Fi
lo
d
el B
an
c o
Cord
o
n
e
l
lo
V
a
l
l
o
n
e
F
onta
n
a
Briga
n
t
i
n
i
LEGEND
pre-MIS 5 post-MIS 5
6.ERUPTIVE
EPOCH
paleo-shorelines I-II-III
( MIS 5 )
1. ERUPTIVE EPOCH
2. ERUPTIVE EPOCH
3. ERUPTIVE EPOCH
4. ERUPTIVE EPOCH
5. ERUPTIVE EPOCH
paleo-shoreline A
M. Montagnola
volcanic dome
Brown Tuffs
paleo-detrital deposits
Filicudi Porto
Pianode
lPorto
Capo Graziano
Le Punte
Monte Guardia
Pecorini a mare
Monte Terrione
Va
ll
e
c
h
iesa
Chiumento
Riberosse
Monte Montagnola
Punta Stimpagnato
Sc
iar
a
C
os
t
a
d
e
l
l
o
S
c
i
a
ra
t
o
Grotta del Bue Marino
Punta Perciato
Scoglio la Mitra
Punta Zotta
Scoglio Giafante
Si
c
c
a
g
n
i
Casa Ficarisi
Fossa Felci
Case dello
Zucco Grande
Punta dello Zucco Grande
Canna
Scoglio di Montenassari
173.57
349.0
739.3
425.0
115.3
512.0
1:35000
Scale
01 Km
N
1
6a
2
3
4
5
6b
7
1
1
1
2
2
3
3
3
3
3
3
4
4
5
5
5
6a
6a
6a
6a
6a
6a
6b
7
7
7
The Aeolian Volcanic District: volcanism and magmatism
89
formed from ca. 430 to 3 ka (Gillot 987) by six main
volcanic edices showing a rough -wards migration
(F. 8).
The eruptive history is described by six eruptive
epochs subdivided by quiescent periods and by marine
terraces attributed to the last interglacial (MIS 5) and to
a generic pre-MIS 5 age (possibly MIS7/9). The oldest
products are represented by basaltic lavas and scoriae of
Pizzo di Corvo, Pizzo Capo (intersected by numerous
feeding dykes along their eroded anks) and Mt. Rivi
volcanic edices, emplaced during the rst to third
eruptive epochs in a pre-MIS7/9 evolutionary stage
(dated at 45-430 ka). After the formation of MIS 9/
marine deposits, the fourth eruptive epoch (pre-MIS 5
stage) determined the construction of the huge Mt.
Fossa delle Felci stratocone, in the sector of Salina,
through the emplacement of lava ows and scoriae.
These products show the rst signicant change in
magma composition and eruptive style on Salina, from
the basaltic composition of the basal strombolian and
eusive rocks (≈75% of the tot. volume), similar to
those of the older eruptive epochs, to strombolian and
sub-plinian fallout deposits and thick viscous, andesitic
to dacitic lava ows (the latter characterized by an over-
all decrease in the SiOcontent with time).
Following the formation of staircased marine ter-
races during main peaks of the last interglacial (from
24 to 8 ka - Lucchi et alii 2004), the Mt. dei Porri stra-
tocone was entirely built in the W portion of Salina dur-
ing the fth eruptive epoch (between 75 and 60 ka -
Gillot 987). Firstly, widespread and thick, andesitic to
dacitic Grey Porri Tus deposits are emplaced during
strong hydromagmatic explosions giving rise to turbu-
lent pyroclastic density currents and determined the
building of a basal tu ring. Then, this exceptionally vi-
olent activity was followed by continuous strombolian
and eusive volcanic activity that determined the em-
placement of andesitic scoriae and lava ows building
the summit stratocone.
After a long quiescent period, the last eruptive epoch
on Salina is characterized by volcanic activity of Pollara
eruptive centre, in the portion of the island. The ini-
tial activity of Pollara consisted of the emission of
dacitic lava ows (at ca. 35 ka), which are exposed at
Punta di Perciato and Scoglio Faraglione. Then, Pollara
apparently remained quiet for a relatively long period,
during which magma dierentiated in a shallow reser-
voir, with its most evolved portion being dacitic to rhy-
olitic. An intrusion of fresh, and hotter, basaltic magma
into the reservoir triggered the violently explosive erup-
tions which determined the emplacement of thick and
widespread pyroclastic deposits consisting of mac sco-
riae and rhyolitic pumices, at ca. 23 and 3 ka (Calanchi
et alii 993). This explosive activity built a km-diame-
ter crater (carved deeply into the ank of Mt. dei
Porri) that was subsequently lled by lacustrine vol-
caniclastic deposits.
6. 2. 2. Lipari
Lipari Island (602 m a.s.l.) emerges from the --
oriented broad volcanic belt, which includes also Salina
and Vulcano edices. Lipari is a complex volcanic appa-
ratus made up of several distinct eruptive centres, over-
lapping in space and time during the last 220 ka. The
youngest activity occurred around 580 (Cortese et alii
986), so that Lipari should be considered a still active
volcano, even if the only evidence is represented by low-
F. 8. Geological sketch map of Salina Island, drawn according to distinct and successive eruptive epochs.
W
W
W
W
W
W
V
V
V
V
V
V
V
V
V
V
W
W
W
W
W
W
W
W
W
W
W
W
W
S.Marina Salina
Malfa
Rinella
Leni
Monte
dei
Porri
Monte
Fossa delle Felci
Pizzo di Corvo
Pollara
Monte Rivi
Pizzo Capo
Capo Faro
Lingua
Punta Grottazza
Punta delle Tre Pietre
Monte
Stella
Punta di Marcello
Punta Sallustro
Praiola
Scoglio
Faraglione
Punta di Perciato Punta di Scario
Quart
a
r
o
l o
P
or
tel
la
Vall
on
e
d
el
C
ast
agn
o
C
al
d
a
r
a
V
al
l
o
n
ed
ei
Z
app
ini
Serro
F
a
v
a
r
o
l
o
Val
lone
M
as
trognoli
V
a
l
l
o
ne
de
lL
u
po
Pian
o del V
es
covo
Vallo
nede
lla
Spina
S
e
r
r
a
d
iP
o
llar
a
Punta Fontanelle
Punta di Megna
Torricella
V
al
d
i
c
h
i
es a
859.51
476.0
299.41
240.0
962.24
854.5
584.0
42.96
LEGEND
pre-
MIS 5 post-MIS 5
pre-
MIS 7/9
1. ERUPTIVE EPOCH
2. ERUPTIVE EPOCH
3. ERUPTIVE EPOCH
4. ERUPTIVE EPOCH
paleo-shoreline A
( MIS 7/9 )
paleo-shorelines I-II-III
( MIS 5 )
5. ERUPTIVE EPOCH
Brown Tuffs
6. ERUPTIVE EPOCH
1:50000
Scale
01 Km
N
1
2
3
4
5
6
5a
11
1
1
2
2
2
3
3
3
3
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
5
5a
5a
5a
5a
6
6
6
6
G. De Astis et alii
90
temperature springs and fumaroles. The eruptive histo-
ry has been described (Tranne et alii 2002a) through ve
eruptive epochs separated by periods of dormancy, tec-
tonic collapses and successive marine terraces formed
during main peaks of the last interglacial (F. 9).
The oldermost CA basaltic andesitic volcanic rocks
outcrop along the side of Lipari and are emplaced
during the rst eruptive epoch (223-30 ka) from scat-
tered eruptive centres aligned along a main - and a
minor - tectonic trend. The eruptive style is mainly
strombolian and eusive, but some of the eruptive cen-
tres are characterized by a subordinate hydromagmat-
ic starting. Around 30 ka, the second eruptive epoch
of Lipari determined the building of Mt. Chirica stra-
tocone and the basal portion of Mt. Sant’Angelo stra-
tocone, which are roughly --aligned in the central
strip of the island, marking a signicant shifting of the
location of eruptive centres. Moreover, the second
eruptive epoch shows a clear change of morphology of
eruptive centres (from scattered eruptive centres to
large stratocones), eruptive style (from strombolian/
eusive to mainly hydromagmatic) and petrochemical
features of the erupted products that range from CA
basaltic andesites to CA/HKCA basaltic andesites to
andesites.
During last interglacial, Lipari is mostly characterized
by intense reworking in marine environment leading to
the formation of three staircased marine terraces and
by coeval volcanic activity. During the third eruptive
epoch (05-80 ka), Mt. Sant’Angelo stratocone contin-
ued to be active in three successive eruptions separated
by quiescence periods, with no signicant changes of
the eruptive style and a gradual petrochemical evolu-
tion of erupted products from CA/HKCA basaltic
andesites/andesites to HKCA andesites/ dacites. To
be mentioned during this period is the eusion of
cordierite-bearing lava ows related to partial assimila-
tion of crustal rocks. Around 90-80 ka, the Mt. Chirica
stratocone is subordinately active with the eusion of
thick HKCA andesitic lava ows.
A long quiescent period followed on Lipari, which
was aected by the emplacement of thick pyroclastic
deposits related to strong and recurrent external
explosive activities. In particular, the so-called Brown
Tus were emplaced between 80 and 5 ka. They are
browny ash pyroclastic products related to highly ex-
plosive eruptions from vent(s) located within the La
Fossa caldera on Vulcano. Dierent and successive
Brown Tu layers build a thick pyroclastic succession
(with several intercalated tephra layers), which has been
F. 9. Geological sketch map of Lipari Island, drawn according to distinct and successive eruptive epochs.
W
W
W
W
W
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
W
W
W
W
W
W
W
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
W
W
W
W
W
LEGEND
pre-MIS 5
post-MIS5 sin-MIS 5
paleo-shoreline I
paleo-shoreline II
paleo-shoreline III
3. ERUPTIVE
EPOCH
1. ERUPTIVE EPOCH
2. ERUPTIVE EPOCH
3 rd eruption
4. ERUPTIVE EPOCH
5. ERUPTIVE EPOCH
1st - 2nd eruption
W
W
W
W
V
V
V
V
V
V
V
V
V
V
V
V
V
V
Monte Guardia
Monte Giardina
Capparo
Punta del Perciato
Punta della Crapazza
Portinente
Castello
Punta le Grotticelle
Timpone Carrubbo
Monte
Mazzacaruso
Timpone Pataso
Timpone Ospedale
Monte S.Angelo
Monte Chirica Monte Pilato
Canneto
Monterosa
Chiesa Vecchia
Acquacalda
Porticello
V
a
l
l
e
M
u
r
i
a
Q
u
a
t
t
r
o
c
c
h
i
For
gi
a
Ve
cchia
Va
l
l
o
n
e
de
lGabe
llo
tto
Pia
n
o
c
o
nt
e
Pignataro di Fuori
Marina Lunga
Porto Pignataro
Valle di Pero
Pietrovito
Timpone Croci
1:60000
Scale
01 Km
N
369.44
593.7
334.6
602.2
348.6
450.1
308.4
239.2
Brown Tuffs
1
2
5
3a
3b
4b
4a
1
1
1
1
1
2
2
2
3a
3a
3b
3b
4a
4a
4a
4b
4b
4b
5
5
5
5
The Aeolian Volcanic District: volcanism and magmatism
9
correlated across the entire Aeolian archipelago (and on
Capo Milazzo) and represent a fundamental strati-
graphic marker. In particular, Lower, Intermediate and
Upper Brown Tus can be identied by the interbed-
ding of Ischia-Tephra and Mt. Guardia tephra layers
(Lucchi et alii, submitted).
Between 40 and 3 ka, the fourth eruptive epoch of
Lipari determined the building of the entire southern
sector of the island through the emplacement of
superposed, viscous endogenous lava domes and
pumiceous pyroclastic products, HKCA rhyolitic in
composition. Volcanic activity was articulated in four
successive eruptions, each of them consisting of an ef-
fusive phase, characterized by the extrusion of - and
--aligned lava domes, and an associated explo-
sive phase that generally preceded the recurrent eusive
ones and determined the building of wide tu cones.
To be mentioned is the emplacement of Mt. Guardia
widespread pumiceous pyroclastic products that are
correlated at a regional scale and useful as fundamental
stratigraphic markers. With respect to the older ones,
the fourth eruptive epoch marks a signicant shifting of
eruptive centres, a change of morphology of volcanic
edices (from stratocones to lava domes) and of petro-
chemical features of the erupted products. Volcanic
products are emplaced within the morphologic depres-
sion created by a tectonic collapse nearby Quattrocchi,
which is a site of structural weakness and favours the
upwelling of magmas. The collapse is dated between
ca. 00 and 70 ka and is suggested to represent the
northern limit of a wide caldera-type structure, the
southern limit of which is represented by the multi-col-
lapse La Fossa caldera (De Astis et alii 2006b).
The fth eruptive epoch on Lipari determined the
emplacement of its most recent HKCA rhyolitic vol-
canic products in the sector of the island (dated be-
tween ka and 580 ). The eruptive activity is con-
ditioned by the main - tectonic trend and is
arranged in two main eruptions characterized by a fair-
ly similar pattern of activity, with a starting explosive
phase and the nal eusion of superimposed lava
domes/couleès. The extrusion of the socalled ‘Rocche
Rosse obsidian coulée’ is, at the present state of knowl-
edge, the last phase of volcanic activity on Lipari.
As a whole, volcanites on Lipari have mac to silicic
compositions, with CA and HKCA anities, and a few
rocks can be referred to island arc tholeiites or SHO
suites. The steep increase in KO passing from mac to
intermediate and acid rocks, the distinct trends shown
by several incompatible elements in the silicic rocks and
the occurrence of xenoliths and xenocrysts in several
products make the petrogenesis of Lipari a complex
problem that still calls for an adequate study.
6. 2. 3. Vulcano
Vulcano Island (500 m a.s.l.) is the southernmost
emerged tip of the broad, mostly submarine --
aligned volcanic belt that includes also Lipari and Sali-
na. Volcanological and magmatological studies aimed
to reconstruct the evolution of the island allowed sev-
eral stages of volcanic activity to be identied (Keller
980, De Astis et alii 997b). According to the most re-
cent stratigraphic reconstruction by De Astis et alii
(2006b, and references therein), the eruptive history of
Vulcano developed between ~30 ka and 888-890
during seven successive eruptive epochs separated by
main quiescent stages and recurrent sector collapses
producing multi-phase caldera structures (F. 0). Al-
though marine deposits are lacking on Vulcano, a cor-
relation is established with volcanic successions on the
other islands of the archipelago on the basis of accurate
stratigraphy and tephrochronology, and of available ra-
diometric ages: thus, the rst four eruptive epochs de-
veloped contemporaneously to the last interglacial, and
the fth and sixth eruptive epochs during the post-MIS
5 evolutionary stage.
The oldermost volcanic products outcrop along the
side of the island and are represented by SHO lava ows
and scoriae related to a presently submerged vent (rst
eruptive epoch). Then, from ~20 to 00 ka (second
eruptive epoch), a huge stratocone (known as Vulcano
Primordiale) was built through the emplacement of an
alternance of HKCA to SHO, basaltic andesitic to
shoshonitic lava ows and scoriae. Around 00 ka, the
summit of the stratocone was aected by the Caldera del
Piano volcanotectonic collapse. During the following
third eruptive epoch (~00-94 ka), the caldera morpho-
logic depression was partially lled by thick basaltic lava
ows with SHO anity, eused from vents located
along the ring faults bordering the side of the caldera
depression. Those lava ows are displaced by a subse-
quent volcano-tectonic collapse representing the rst
event connected to the multi-collapse formation of the
Caldera della Fossa. Then, volcanic activity resumed
from vents located along the rim of the Caldera del Pi-
ano (fourth eruptive epoch). In particular, from ~80 ka,
the Mt. Aria and Timpa del Corvo vents were active de-
termining the emplacement of SHO (and minor HKCA
basaltic andesitic) pyroclastic products and lava ows
that progressively lled the morphologic depression of
the Caldera del Piano (toward ) and along the south-
ern slopes of Vulcano Primordiale. In the time span from
~80 to 5 ka, eruptive centres and ssures shifted to-
wards - in alternance with partial collapse and
caldera-forming events, nally producing the present
multi-phase La Fossa Caldera. Noteworthy, recent stud-
ies (Lucchi et alii, submitted) have suggested that a wide
tu cone could have been active within the area present-
ly occupied by La Fossa Caldera, probably in a position
similar to La Fossa cone and with similar features (fth
eruptive epoch). It basically produced explosive erup-
tions ranging from strombolian to hydromagmatic,
sometimes generating pyroclastic density currents able
to override the topographic obstacle represented by La
Fossa caldera walls and/or to reach the southern part of
Lipari, in the more energetic pulses. This determined the
emplacement of the thick pyroclastic successions out-
cropping within the Caldera del Piano morphologic de-
pression. On the basis of still ongoing investigations,
Lucchi et alii (submitted) we propose that these pyro-
G. De Astis et alii
92
clastic successions represent the proximal facies of the
Lower and Intermediate Brown Tu deposits with ages
older than 22-20 ka. Minor volcanic activities from vents
located within or bordering the Piano Caldera area, also
characterized the fth eruptive epoch and erupted the
most primitive SHO lava ows and scoriae outcropping
on Vulcano (La Sommata hill, etc.).
The sixth eruptive epoch occurred between 28 and 20
ka from vents located along the ring faults bordering
the caldera collpases along the entire side of the Vul-
cano Island. Trachy-rhyolitic lava domes (28-26 ka) in
the present sector of Lentia complex and the SHO
Spiaggia Lunga (24 ka) and Quadrara (2.3 ka) fall
deposits are emplaced.
Finally, the seventh eruptive epoch (from 20 ka to
Present) caused the emplacement of the most recent
volcanic products on Vulcano. They are represented by
trachytic and rhyolitic lava domes in the sector of Lentia
(5-8 ka) and by the scoriae and lava ows from the Mt.
Saraceno vent (~8-8.3 ka). Anyway, volcanic activity fo-
cuses within the morpholog ic depression of the Caldera
della Fossa. Firstly, the Piano Grotte dei Rossi Tus
(20-5.3 ka - De Astis et alii 997, 2006b) were produced
during several but similar explosive eruptions from
vents located within La Fossa Caldera. On the basis of
stratigraphical matching, and similar lithological, tex-
tural and petrochemical features, we suggest that they
represent the proximal facies of the Upper Brown Tus.
Over tha last 6 ka, La Fossa Cone (39 m a.s.l.) was built
in the middle of the homonimous caldera through re-
current explosive (and subordinately eusive) activities
determining the emplacement of superposed pyroclas-
tic deposits and a few viscous lava ows. Moreover, dur-
ing the last 2 ka, the Vulcanello lava shield – shoshonitic
in composition – with 3 small coalescent cones overly-
ing the lava, formed. The last eruption on the island oc-
curred from August 888 to March 890, with emission
of pyroclastic material from La Fossa Cone, and its de-
scription gave origin to the denition of vulcanian-type
eruption in the literature (Mercalli and Silvestri 89). At
present, Vulcano is characterized by shallow seismicity
(Md < 2.6; depth of foci < 4 km) and intense fumarolic
activity focused on the northern edge of La Fossa crater,
which went through anomalous gas temperatures re-
peatedly after 890: in 923 (Tmax = 65 °C - Sicardi 94),
in 993 (Tmax = 690 °C - Chiodini et alii 995), in 2005
(Tmax=450 °C; - reports). Also during the last
2 decades, several increases of the physico-chemical
parameters monitored at La Fossa occurred (e.g., T,
F/Cl, He/He; COux - Granieri et alii 2006, and ref-
erences therein), but none of them originated new
eruption from the cone.
As a whole, Vulcano consists of mac to silicic HKCA
to SHO products and exhibits a progressive increase in
potassium contents with time, whereas evolved prod-
ucts appear just at ~30 ka. Older products are mostly
mac HKCA to SHO rocks that display rather variable
radiogenic isotope signatures, (Sr/Sr = 0.7044-
0.70520, with correlation indicating RTFA processes
(see De Astis et alii, 997b). The lava domes in the sec-
F. 0. Geological sketch map of Vulcano Island, drawn according to distinct and successive eruptive epochs.
N
7. ERUPTIVE
EPOCH
5. ERUPTIVE
EPOCH
6. ERUPTIVE EPOCH
3. ERUPTIVE EPOCH
4. ERUPTIVE EPOCH
1. ERUPTIVE EPOCH
2. ERUPTIVE EPOCH
Lower and Intermediare
Brown Tuffs
Piano Grotte dei Rossi tuffs
(Upper Brown Tuffs)
La Fossa, M.Saraceno and
M.Lentia products
pyroclastic products
outcropping within the
Caldera della Piano
LEGEND
sin-MIS 5
post-MIS 5
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
W
V
V
V
V
V
V
V
V
V
V
V
V
W
W
W
W
W
W