Monument Future. Siegfried Siegesmund

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СКАЧАТЬ point chiseled face (main body of Stazione Centrale, U. Stacchini 1912/31, Milan; former Banca Commerciale now Ragioneria Comunale, L. Beltrami 1913/23, Milan).

      Other sedimentary rocks coming from Karst, with similar origin (organic limestone) and composition, were employed in 20th century architecture for flooring and cladding: Gabria Tomadio, Lipos, Repen.

       Pietra di Finale

      Organic carbonate rock (shell limestone; bio-sparite / packstone). Colour: pinkish to yellowish with some variegations with evidence of shells of Bivalves (Chlamys). Mineral: calcite. Decay morphologies: surface erosion; sulphate skin formation. Geology: “Calcare di Finale Ligure” formation (lower 44Miocene) of post-orogenetic deposits of the “Bacino del Finalese”. Quarry: near Orco-Feglino, few kilometres north of Finale Ligure (Savona). Use: thick point chiseled slabs mainly employed for cladding (Università L. Bocconi, G. Pagano 1941, Milan; Palazzo del Toro, E. Lancia 1939, Milan).

       Rosso Amiata

      Nodular carbonate rock with ammonite shells (limestone, biomicrite). Colour: dark red with white veins and pink shades. Minerals: calcite, haematite. Decay morphologies: surface erosion, sulphate skin formation, chromatic alteration. Geology: “Calcare ammonitifero” formation (lower Lias) of the non-metamorphic series of Tuscany. Quarry: south of Roccalbegna (Grosseto province). Use: polished slabs mainly for flooring in residential and public buildings (Casa Wassermann, a four-storeys urban residence with an accurate choice of coloured stones for flooring, P. Portaluppi 1934, Milan).

       Portasanta di Caldana

      Carbonate rock (pseudo-breccia, limestone). Colour: red to purple with white, purple or pink irregular spots and very thin grey or purple veins. Mineral: calcite. Decay morphologies: surface erosion, sulphate skin formation, chromatic alte-ration. Geology: “Calcare mas-siccio” formation (Hettangian, lower Lias) of the non-metamorphic series of Tuscany. Quarry: Caldana (south of Gavorrano, Grosseto province). Use: polished slabs mainly for flooring in residential buildings together with other coloured marbles, Casa Wassermann). A significant use is displayed on the great staircases of Milan’s Stazione Centrale (U. Stacchini 1912/31): the big shafts are made assembling moulded pieces of curvilinear shape and pieces of fluted shape.

       Travertino di Rapolano

      Carbonate stone with spongy appearance. Colour: creamy-white or yellowish; Mineral: calcite. Decay morphologies: roughening, sulphate skin formation, soot deposits in the cavities. Geology: carbonate deposition from hot springs (Upper Pleistocene). Quarry: near Serre di Rapolano, east of Sienna (Tuscany). Use: the stone was taken in great consideration during the Thirties as blocks and thick slabs with sawed face for cladding (Main Atrium of the Stazione Centrale; Ca’ Brütta, lower part of façades, G. Muzio 1922; Palazzo della Borsa, colonnaded façade, P. Mezzanotte 1932, Milan). This stone is very similar to Travertino romano (Lapis Tiburtinus, coming from Tivoli-Guidonia, Rome), largely used in ancient Rome and by Baroque architects, later (since the third decade of 20th century) spread in the whole Italian territory.

       Verde Alpi

      Metamorpihc rock (ophicalcite). Colour: dark green colour with several light green elements and a large grid of white calcitic veins. Minerals: serpentine, calcite and magnetite. Decay morphologies: roughening, chromatic alteration. Geology: “Unità Ofiolitiche dello Chenaillet” (Jurassic). Quarry: near Cesana Torinese in the valle di Susa, near the French border (Torino province). Use: mainly polished slabs for flooring (Casa Wassermann).

      Other ophicalcites (Verde Champ de Praz, Verde Issorie), with similar texture and composition and quarried in the eastern part of Valle d’Aosta (Chatillon), were also largely employed for flooring in the 20th century architecture.

       Rosso di Lèvanto

      Metamorphic rock (ophicalcite). Colour: dark red ground with very irregular white calcitic veins (a variety shows a dark green ground instead of red). Minerals: serpentine, calcite. Decay morphologies: roughening, chromatic alteration. Geology: “Ofioliti liguri”, a group including serpentinite, serpentinized peridotite, gabbro euphotide, diabase and ophicalcite (Upper Jurassic – Lower Cretaceous). Quarry: spread along the coast of Eastern Liguria (Lévanto, Bonassola etc. La Spezia province). Use: mainly polished slabs for cladding, moulded elements were also employed as jambs and lintel in portals and doors (Palazzo di Giustizia, flooring).

       Verde Roja

      Metamorphic rock (clayey schist, easily divisible into slabs). Colour: green with darker silicate veins. Minerals: quartz, mica, chlorite. 45Decay morphologies: scaling. Geology: “Scisti gneiss-sici” formation (Permian). Quarry: upper valley of the river Roja (Colle di Tenda) a former Italian territory assigned to France (dép. Alpes Maritimes) after the WWII. Use: mainly unpolished slabs for cladding or flooring (Casa Fiocchi, cladding, M. Fiocchi 1925 and Stazione Centrale, flooring together with other coloured stones, Milan).

       Marmo di Valle Strona

      Regional metamorphic rock (marble, coarse grain-size). Colour: grey with darker veins. Minerals: calcite, muscovite. Decay morpho-logies: disaggregation, sulphate skin formation. Geology: lenses in the “Dioritico-kinzigitica” formation of the “Ivrea-Verbano Zone”, spread from Valle Strona (Piedmont) to Canton Ticino (Switzerland). Quarry: near the village of Sambughetto (valle Strona, Verbano province). Use: mainly polished slabs for cladding (Palazzo di Giustizia, façades totally coated with this marble). It is worth to note the use of this marble in Naples, very far from the quarry site: Palazzo delle Poste (cladding of the curved façade, G. Vaccaro 1936); Banco di Napoli (cladding of the main hall, M. Piacentini 1940).

       Marmo di Lasa

      Regional metamorphic rock (marble, medium to fine grain-size). Colour: white with bands of various colours (grey to black due to graphite; green to chlorite; pink to zoisite); sometimes groups of little elongate black spots with shaded rims are present and an appropriate cut may produce a particular graphic effect (called Fantastico). Minerals: calcite; graphite, chlorite and zoisite. Decay morphologies: surface erosion, sulphate skin formation. Geology: Laas Unit (micaschist, banded paragneiss and marble) of Ortles-Campo Nappe, Austro-Alpine System (Pre-Permian metamorphic Basement). Quarry: above the village of Lasa-Laas (val Venosta-Vinschgau, Bolzano-Bozen province), the most important one (Weisswasser) was located at an altitude of 1,600 metres and the marble came down the hill using a incline railway. Use: mainly polished slabs for cladding; in some cases, the slabs are disposed in “open book style” (Casa Rustici, G. Terragni 1935, Milan; Torre Rasini, E. Lancia and G. Ponti 1934, Milan).

       Fior di pesco carnico

      Low grade metamorphosed crystalline limestone (marble, fine grain-size). Colour: light grey ground sometimes with pinkish or purplish spots and coarse grained veins. Mineral: calcite, opaque. Decay morphologies: surface erosion, sulphate skin formation. Geology: limestone of organic origin (Devonian) of the “Paleozoico carnico”. Quarry: near Pierabec, north of Forni Avoltri (Udine province). Use: mainly polished slabs for cladding (Palazzo della Provincia, atrium, G. Muzio 1942, Milan). СКАЧАТЬ