Tuscan Magmatic Province

• Tuscan Magmatic Province
• Gavorrano Granite
• Montecatini Lamproite
• Orciatico Lamproite
• Radicofani Volcano
• Roccastrada Rhyolites
• S.Vincenzo Rhyolites
• Sisco Lamproite

Intra Appennine Province

• Intra Appennine Province
• Cupaello
• San Venanzo
Venanzite
Melilitolite

Roman Magmatic Province

• Roman Magmatic Province
• Alban Hills
• Vulsini

Ernici-Roccamonfina Magmatic Province

• Roccamonfina

Mount Vulture Province

• Mount Vulture
• Alvikites (carbonatite)
• Melilitite
• Haüynophyre
• Tephrite

Sicily Magmatic Province

• Sicily Magmatic Province
• Etna
• Iblei
• Ustica

Aeolian Arc

• The Aeolian Arc
• Alicudi
• Lipari
• Vulcano

other sections will be added soon

Montecatini Val di Cecina lamproitic intrusion

The Montecatini Val di Cecina lamproite represents a minor igneous centre of the Tuscan Magmatic Province (Fig.1) and consists of a 4.1 Ma old plug intruded into Miocene marine and lacustrine sediments and Liguride units, and it is bordered by recent normal faults that dissect its original shape (Fig. 2).

Fig.1: Location of intrusive and extrusive rocks of the Tuscany Magmatic Province. Numbers in parentheses indicate ages (in Ma).

Fig.1: Schematic geologic map of Montecatini Val di Cecina area. 1) Thermally metamorphosed rocks; 2) Montecatini Val di Cecina massive facies; 3) Montecatini Val di Cecina jointed facies. Modified after Conticelli et al. ( 1992).

On the basis of field relations and microscopic observations Conticelli et al. (1992) divided the Montecatini Val di Cecina igneous body in three distinct facies:

1) A marginal facies, represented by a few metres of a massive reddish-brown glassy chilled margin. This border facies grades into a massive crystalline facies.
2) Massive crystalline facies represented by a brownish rock which is cut by scarce leucocratic veins. The veins sometimes reach a thickness of 15 cm, and, in some places, widen out into globular masses (ocelli). The latter range in size from few mm up to 25-30 cm.
3) On the west side of the body, a third facies is present, and is in tectonic contact with not metamorphosed country rocks. This facies is columnar jointed, red-brown in colour, and is cut at right angles by a dense grid of rectilinear leucocratic veins with a maximum size of 2.0 cm.

On the basis of the field relationships, it appears possible that the massive crystalline facies represents the original top, whereas the columnar jointed facies correspond to the deepest part, of the Montecatini val di Cecina plug. Successive tectonic movements dissected, tilted and lifted up the two portions of the body giving them their present day arrangement.

Microscopically, the marginal facies is characterizided by large and abundants red-brown phlogopite laths with minor totally replaced skeletal olivine, colourless clinopyroxene, K-feldspar and apatite. Quartz is present only in the most weathered samples as an alteration product (Conticelli et al., 1992).
The massive crystalline and the columnar jointed facies have a porphyritic hypidiomorphic texture with abundant zoned mica, feathery K-feldspar, minor colourless clinopyroxene, apatite, as well as rare oxide, zircon, thorite, quartz and perrierite.

In the columnar jointed facies glomeroporphyritic mica aggregates and upper crustal xenoliths are sometimes present. The micas have a fabric that resembles a primary linear fluidality, due to crystallization and orientation of this phase parallel to the flow direction. These structural characteristics strongly controlled the formation of the joints during cooling of the magma. Veins and ocelli are characterized by a fine-grained, slightly porphyritic texture. K-feldspar is the most abundant phase.

The plug is pervasively intruded by a network of thin leucocratic veins, consisting of dominant sanidine with minor quartz and brown mica, plus accessory apatite. These veinlets probably represent residual felsic melts unmixed from the crystallising minette magma (Conticelli et al. 1992). The Montecatini high-silica lamproite has lower alkali contents than that at Sisco. MgO, Ni, Co and Cr are high, in the range of mantle equilibrated melts, but Sc and V are lower than expected in normal, primitive mantlederived rocks.

Bibliography

• Peccerillo, A. (2005). Plio-quaternary volcanism in Italy (Vol. 365). Springer-Verlag Berlin Heidelberg.
• Conticelli, S., et al. (2004): "Petrologic, geochemical, and isotopic characteristics of potassic and ultrapotassic magmatism in Central-Southern Italy: inferences on its genesis and on the nature of mantle sources." Periodico di Mineralogia 73.1: 153-164.

Thermally metamorphosed rocks

Thermally metamorphosed sediments. Montecatini Val di Cecina lamproite, contact metamorphic aureole, Pisa, Italy. PPL image, 2x (Field of view = 7mm)

Thermally metamorphosed sediments. Montecatini Val di Cecina lamproite, contact metamorphic aureole, Pisa, Italy. PPL image, 2x (Field of view = 7mm)

Thermally metamorphosed sediments. Montecatini Val di Cecina lamproite, contact metamorphic aureole, Pisa, Italy. PPL image, 2x (Field of view = 7mm)

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Lamproite

Phlogopite (brown) and skeletal sanidine (colorless, with feathery texture). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 1x (Field of view = 9mm)	Phlogopite (brown) and skeletal sanidine (colorless, with feathery texture). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 1x (Field of view = 9mm)	Phlogopite (brown) and skeletal sanidine (colorless, with feathery texture). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 1x (Field of view = 9mm)
Phlogopite (brown) and skeletal sanidine (colorless, with feathery texture). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 1x (Field of view = 9mm)	Phlogopite (brown) and skeletal sanidine (colorless, with feathery texture). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 1x (Field of view = 9mm)	Phlogopite (brown) and skeletal sanidine (colorless, with feathery texture). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 1x (Field of view = 9mm)
Phlogopite and skeletal sanidine (I order gray, with feathery texture). Montecatini Val di Cecina lamproite, Pisa, Italy. XPL image, 2x (Field of view = 7mm)	Phlogopite and skeletal sanidine (I order gray, with feathery texture). Montecatini Val di Cecina lamproite, Pisa, Italy. XPL image, 2x (Field of view = 7mm)	Phlogopite and skeletal sanidine (I order gray, with feathery texture). Montecatini Val di Cecina lamproite, Pisa, Italy. XPL image, 2x (Field of view = 7mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite, skeletal sanidine (with feathery texture) and pyroxene. Montecatini Val di Cecina lamproite, Pisa, Italy. XPL image, 2x (Field of view = 7mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite, skeletal sanidine (with feathery texture) and pyroxene. Montecatini Val di Cecina lamproite, Pisa, Italy. XPL image, 2x (Field of view = 7mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite, skeletal sanidine (with feathery texture) and pyroxene. Montecatini Val di Cecina lamproite, Pisa, Italy. XPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)	Phlogopite, skeletal sanidine (with feathery texture) and pyroxene. Montecatini Val di Cecina lamproite, Pisa, Italy. XPL image, 2x (Field of view = 7mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 10x (Field of view = 2mm)	Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)
Phlogopite (brown), skeletal sanidine (colorless, with feathery texture) and pyroxene (colorless, high relief). Montecatini Val di Cecina lamproite, Pisa, Italy. PPL image, 2x (Field of view = 7mm)