Tuscan Magmatic Province

Intra Appennine Province

Roman Magmatic Province

Ernici-Roccamonfina Magmatic Province

Roccamonfina

Mount Vulture Province

Sicily Magmatic Province

Aeolian Arc

other sections will be added soon

Iblei

Schematic Map of E-Sicily. Iblean volcanics in Pink.

The Iblean Plateau has been affected by volcanism from Triassic to Quaternary times. The oldest volcanic rocks in the Iblean Plateau are Triassic and Jurassic in age and have been recovered by drilling. These consist of alkali basalts, hawaiites and basanites containing Ti-clinopyroxene, olivine, plagioclase, Fe-Ti oxides and sporadic kaersutite, biotite and apatite. The oldest oucropping volcanics are Cretaceous to Paleocene in age (84 to 54 Ma) and are found in the Capo Passero area. These rocks consist of almost aphyric to strongly porphyritic alkali basalts and basanites containing variable amounts of olivine, Ti-clinopyroxene, plagioclase. and secondary minerals.

The youngest volcanic activity in this area ranges from Upper Miocene (Tortonian) to Lower Pleistocene and occurs along NE-SW extensional faults bordering graben zones in the northernmost sector of the Iblean Plateau. The volcanism was dominated by fissure-type eruptions, which formed monogenetic centres and lava flows of variable size. Overall, Miocene to Quaternary volcanic rocks cover an area of about 250 km2 and have an estimated volume of about 30-40 km3. The volcanic products rest over a sedimentary substratum of Upper Cretaceous and Early Tertiary reef and marly limestones and Oligo-Miocene calcarenites, and are interfingered with Mio-Pleistocene calcarenites, evaporitic rocks and silicoclastic sediments.

Miocene volcanic cycle (about 7 to 4.9 Ma) was prevailingly submarine and erupted volcanoclastites from maar-type centres, along with volumetrically less significant lavas. Rocks have compositions similar to the younger Plio-Pleistocene activity, but Na-alkaline rock (alkalibasalt, basanite, nephelinite and ankaratrite) prevail over subalkaline volcanics. Miocene alkaline rocks are variably porphyritic with phenocrysts of olivine and clinopyroxene set in a groundmass consisting of the same phases, plus nepheline, Fe-Ti oxides, apatite and some plagioclase and glass. Tholeiites are aphyric to poorly porphyritic with olivine, clinopyroxene, some orthopyroxene and plagioclase microphenocrysts set in a matrix containing the same phases plus Fe-Ti oxides and sporadic glass. Xenoliths of both crustal and mantle origin occur in some tuffbreccias around diatremes. Ultramafic xenoliths consist mainly of spinel-harzburgites and lherzolites, plus minor websterites, and clinopyroxenites. Crustal xenoliths are predominantly basic granulites and minor gabbros, diorites and anorthosites.

The Plio-Peistocene activity is by far the best studied. It took place during Lower-Middle Pliocene (4.9 to 3.5 Ma) and Upper Pliocene-Lower Pleistocene (2.4 to 1.5 Ma). The earlier products are principally submarine and are represented by volcanoclastic products, pillow lavas and minor subaerial lava flows. The Upper Pliocene-Lower Pleistocene activity erupted lava in subaerial to shallow marine environments.

Iblean Plio-Quaternary magmas range from basalts and basaltic andesites to nephelinites, and straddle the boundary between the alkaline and subalkaline fields of Irvine and Baragar. Subalkaline basalts are the dominant rock types and range from slightly oversaturated (qz-tholeiites) to slightly undersaturated (ol-tholeiites) in silica. Alkaline rocks have a sodic affinity and include alkali basalts, hawaiites, basanites, and nephelinites.

Bibliography

• Peccerillo. A. Plio-Quaternary Volcanism in Italy. (2005)

Basalt
Olivine (with Iddingsite alteration) and Pyroxene embedded in a glassy groundmass with plagioclase laths. PPL image, 2x (Field of view = 7mm)	Olivine (with Iddingsite alteration) and Pyroxene embedded in a glassy groundmass with plagioclase laths. XPL image, 2x (Field of view = 7mm)	Olivine (with Iddingsite alteration) and Pyroxene embedded in a glassy groundmass with plagioclase laths. PPL image, 2x (Field of view = 7mm)
Olivine and Pyroxene embedded in a glassy groundmass with plagioclase laths. XPL image, 2x (Field of view = 7mm)	Olivine (with Iddingsite alteration) and Pyroxene embedded in a glassy groundmass with plagioclase laths. PPL image, 2x (Field of view = 7mm)	Olivine and Pyroxene embedded in a glassy groundmass with plagioclase laths. XPL image, 2x (Field of view = 7mm)
Olivine and Pyroxene embedded in a glassy groundmass with plagioclase laths. XPL image, 2x (Field of view = 7mm)	Olivine and Pyroxene embedded in a glassy groundmass with plagioclase laths. XPL image, 2x (Field of view = 7mm)	Olivine and Pyroxene embedded in a glassy groundmass with plagioclase laths. PPL image, 2x (Field of view = 7mm)
Pyroxene with sieve texture. PPL image, 2x (Field of view = 7mm)	Pyroxene with sieve texture. XPL image, 2x (Field of view = 7mm)	Pyroxene with sieve texture. PPL image, 2x (Field of view = 7mm)
Pyroxene with sieve texture. XPL image, 2x (Field of view = 7mm)	Pyroxene with sieve texture. PPL image, 2x (Field of view = 7mm)	Pyroxene with sieve texture. XPL image, 2x (Field of view = 7mm)
Olivine (altered by Bowlingite) and Pyroxene crystals. PPL image, 2x (Field of view = 7mm)	Olivine (altered by Bowlingite) and Pyroxene crystals. XPL image, 2x (Field of view = 7mm)	Olivine (altered by Bowlingite). PPL image, 2x (Field of view = 7mm)
Olivine and Pyroxene crystals. PPL image, 2x (Field of view = 7mm)	Olivine and Pyroxene crystals. XPL image, 2x (Field of view = 7mm)	Olivine and Pyroxene crystals. XPL image, 2x (Field of view = 7mm)
Olivine, Pyroxene and calcite fillng a vescicle. PPL image, 2x (Field of view = 7mm)	Olivine, Pyroxene and calcite fillng a vescicle. XPL image, 2x (Field of view = 7mm)	Skeletal plagioclase in a Glassy basalt. PPL image, 10x (Field of view = 2mm)
Skeletal plagioclase in a Glassy basalt. PPL image, 10x (Field of view = 2mm)	Skeletal plagioclase and olivine in a Glassy basalt. PPL image, 10x (Field of view = 2mm)	Skeletal plagioclase and olivine in a Glassy basalt. PPL image, 10x (Field of view = 2mm)

Capo Passero Alkaline Basalt
Olivine crystals embedded in a groundmass with plagioclase laths. PPL image, 2x (Field of view = 7mm)	Olivine crystals embedded in a groundmass with plagioclase laths. PPL image, 2x (Field of view = 7mm)	Olivine crystals embedded in a groundmass with plagioclase laths. XPL image, 2x (Field of view = 7mm)
Olivine altered by Bowlingite. PPL image, 10x (Field of view = 2mm)	Olivine altered by Bowlingite. PPL image, 10x (Field of view = 2mm)	Olivine altered by Bowlingite. PPL image, 10x (Field of view = 2mm)
Olivine altered by Bowlingite. PPL image, 10x (Field of view = 2mm)	Olivine altered by Bowlingite. PPL image, 10x (Field of view = 2mm)	Olivine altered by Bowlingite. PPL image, 10x (Field of view = 2mm)
Calcite filling vescicles in a Basaltic Scoria. PPL image, 2x (Field of view = 7mm)	Calcite filling vescicles in a Basaltic Scoria. XPL image, 2x (Field of view = 7mm)	Calcite filling vescicles in a Basaltic Scoria. PPL image, 2x (Field of view = 7mm)
Olivine crystals altered by Bowlingite. PPL image, 2x (Field of view = 7mm)	Olivine crystals altered by Bowlingite. PPL image, 2x (Field of view = 7mm)	Olivine crystals altered by Bowlingite. XPL image, 2x (Field of view = 7mm)
Olivine crystals altered by Bowlingite. XPL image, 2x (Field of view = 7mm)	Olivine crystals altered by Bowlingite. PPL image, 2x (Field of view = 7mm)	Olivine crystals altered by Bowlingite. PPL image, 2x (Field of view = 7mm)
Olivine crystal altered by Bowlingite. PPL image, 2x (Field of view = 7mm)	Olivine crystal altered by Bowlingite. XPL image, 2x (Field of view = 7mm)	Olivine crystal altered by Bowlingite. PPL image, 2x (Field of view = 7mm)
Cristalli di olivina, con bowlingite nelle fratture, immersi in una pasta di fondo composta da plagioclasi. Immagine a NX, 2x (lato lungo = 7mm)	Cristalli di olivina, con bowlingite nelle fratture, immersi in una pasta di fondo composta da plagioclasi. Immagine a NX, 2x (lato lungo = 7mm)	Cristalli di olivina, con bowlingite nelle fratture, immersi in una pasta di fondo composta da plagioclasi. Immagine a N//, 2x (lato lungo = 7mm)

Mantellic Xenolith
Olivine (altered by Bowlingite) + Pyroxene Xenolith in a Basalt. PPL image, 2x (Field of view = 7mm)	Olivine (altered by Bowlingite) + Pyroxene Xenolith in a Basalt. XPL image, 2x (Field of view = 7mm)	Olivine (altered by Bowlingite) + Pyroxene Xenolith in a Basalt. PPL image, 2x (Field of view = 7mm)
Olivine (altered by Bowlingite) + Pyroxene Xenolith in a Basalt. PPL image, 2x (Field of view = 7mm)	Olivine (altered by Bowlingite) + Pyroxene Xenolith in a Basalt. XPL image, 2x (Field of view = 7mm)	Olivine (altered by Bowlingite) + Pyroxene Xenolith in a Basalt. PPL image, 2x (Field of view = 7mm)
Olivine (altered by Bowlingite) + Pyroxene Xenolith in a Basalt. XPL image, 2x (Field of view = 7mm)	Olivine crystal with fracture filled by Bowlingite and calcite. XPL image, 10x (Field of view = 2mm)	Olivine crystal with fracture filled by Bowlingite and calcite. XPL image, 10x (Field of view = 2mm)
Olivine crystal with fracture filled by Bowlingite and calcite. XPL image, 10x (Field of view = 2mm)	Olivine crystal with fracture filled by Bowlingite and calcite. XPL image, 10x (Field of view = 2mm)	Olivine (replaced by Calcite) + Pyroxene Xenolith in a Basalt. PPL image, 2x (Field of view = 7mm)
Olivine (replaced by Calcite) + Pyroxene Xenolith in a Basalt. XPL image, 2x (Field of view = 7mm)	Olivine (replaced by Calcite) + Pyroxene Xenolith in a Basalt. PPL image, 2x (Field of view = 7mm)	Olivine (replaced by Calcite) + Pyroxene Xenolith in a Basalt. XPL image, 2x (Field of view = 7mm)