The Calcare di Aurisina (Also known as Aurisina Formation, “Formazione di Monrupino”, Trieste Karst Limestone formation, “Repen formation”, “Sežana formation” and “Lipiza formation”) is a

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

geologic formation in

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

and

Slovenia Slovenia, officially the Republic of Slovenia, is a country in Central Europe. It borders Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the south and southeast, and a short (46.6 km) coastline within the Adriati ...

. This

limestones Limestone is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Limestone forms when these ...

are found in the

Trieste Trieste ( , ; ) is a city and seaport in northeastern Italy. It is the capital and largest city of the Regions of Italy#Autonomous regions with special statute, autonomous region of Friuli-Venezia Giulia, as well as of the Province of Trieste, ...

area and are of

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

(

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya ( million years ago) and 83.6 ± 0.7 m ...

Campanian The Campanian is the fifth of six ages of the Late Cretaceous epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campa ...

) age, being a local record of

Carbonate platform A carbonate platform is a Sedimentary rock, sedimentary body which possesses topographic relief, and is composed of Autochthon (geology), autochthonic calcareous deposits. Platform growth is mediated by Sessility (zoology), sessile organisms whose ...

limestones, historically quarried by cutting large blocks using steel wire, what has allowed more access to them, as numerous quarries allow excellent exposure. Due to being cut into large blocks and slabs, that usually end stored near the quarries, detailed, three-dimensional study of the rock's composition and fossils can be easily done.

Characteristics

The ''Aurisina limestone'' has usually a light grey background, sometimes appearing

hazelnut The hazelnut is the fruit of the hazel tree and therefore includes any of the nuts deriving from species of the genus '' Corylus'', especially the nuts of the species ''Corylus avellana''. They are also known as cobnuts or filberts according to ...

in color. It is known for its high purity, compactness, and uniformity. The quarries where it is extracted consist of thick, solid layers of stone. Different varieties of Aurisina marble are distinguished by shades of grey and the distribution, size, and orientation of the organic remains within the stone. Well-known varieties include ''Aurisina Fiorita'', ''Aurisina Lumachella'', ''Aurisina Chiara'', and ''Roman Stone'', among others. Aurisina marble's chemical composition and physical properties make it ideal for use in architecture, both for structural and decorative purposes, as well as in statues and monuments. The stone is valued for its durability and aesthetic appeal in various applications.

Historical Importance

The ''Aurisina Limestone'' has been used since the

Roman Republic The Roman Republic ( ) was the era of Ancient Rome, classical Roman civilisation beginning with Overthrow of the Roman monarchy, the overthrow of the Roman Kingdom (traditionally dated to 509 BC) and ending in 27 BC with the establis ...

. Evidence from ancient monuments in

Aquileia Aquileia is an ancient Roman city in Italy, at the head of the Adriatic at the edge of the lagoons, about from the sea, on the river Natiso (modern Natisone), the course of which has changed somewhat since Roman times. Today, the city is small ( ...

, a Roman colony founded in 181 BC, suggests that quarrying began in the

1st century BC The 1st century Before Christ, BC, also known as the last century BC and the last century Common Era , BCE, started on the first day of 100 BC, 100 BC and ended on the last day of 1 BC, 1 BC. The Anno Domini, AD/BC notation does not ...

and continued until the

5th century AD The 5th century is the time period from AD 401 (represented by the Roman numerals CDI) through AD 500 (D) in accordance with the Julian calendar. The 5th century is noted for being a period of migration and political instability throughout Eurasia. ...

. The stone was widely used in Aquileia for architectural elements, statues, and funerary monuments. The nearby city of Tergeste (modern Trieste) also made extensive use of ''Aurisina Limestone'' for public buildings and sculptures. Its use spread across northern Italy, with artifacts found as far as

Pavia Pavia ( , ; ; ; ; ) is a town and comune of south-western Lombardy, in Northern Italy, south of Milan on the lower Ticino (river), Ticino near its confluence with the Po (river), Po. It has a population of c. 73,086. The city was a major polit ...

. In the post-Roman period, Aurisina marble was notably used in the

Mausoleum of Theodoric The Mausoleum of Theodoric () is an ancient monument just outside Ravenna, Italy. It was built in AD 520 by Theodoric the Great, king of the Ostrogoths, as his future tomb. Description The mausoleum's current structure consists of two decagonal ...

Ravenna Ravenna ( ; , also ; ) is the capital city of the Province of Ravenna, in the Emilia-Romagna region of Northern Italy. It was the capital city of the Western Roman Empire during the 5th century until its Fall of Rome, collapse in 476, after which ...

, built around 520 AD. However, its use declined during the medieval and Baroque periods. In Venice, it was replaced by Istrian stone, but in Trieste, it saw a revival in the 18th century as the city grew following the establishment of the free port by

Emperor Charles VI Charles VI (; ; 1 October 1685 – 20 October 1740) was Holy Roman Emperor and ruler of the Austrian Habsburg monarchy from 1711 until his death, succeeding his elder brother, Joseph I. He unsuccessfully claimed the throne of Spain follow ...

. Notable examples of its use in Trieste include Palazzo Pitteri (1780), the Stock Exchange (1802), and the renovation of the Greek Orthodox Church of San Nicolò dei Greci (1819). ''Aurisina Limestone'''s "golden age" came under the

Austro-Hungarian Empire Austria-Hungary, also referred to as the Austro-Hungarian Empire, the Dual Monarchy or the Habsburg Monarchy, was a multi-national constitutional monarchy in Central Europe between 1867 and 1918. A military and diplomatic alliance, it consist ...

, particularly after the completion of the Southern Railway, connecting Trieste to Vienna. The stone was used in major projects throughout the empire, including the Parliament and Hofburg in Vienna, the State Opera in Budapest, and many buildings in cities like Graz, Munich, and Ljubljana. By 1890, the industry employed over 3,000 workers. After Trieste's annexation to Italy in 1918, ''Aurisina Limestone'' was used in large-scale projects like the Military Shrine of Redipuglia and Milan's Central Station, where 38,000 tons were utilized. During this period, the marble also reached international markets, being used in

Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...

and the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. In the post-war era, ''Aurisina Limestone'' continued to be popular in foreign markets, with notable projects including the Atlanta subway in the U.S., Berlin airport, and La Défense in Paris. In 1989, it was used for Milan Metro's Line 3. More recently, it has featured in prestigious architectural projects, such as Milan's Citylife Shopping District designed by Zaha Hadid and Turin's Lavazza headquarters. Internationally, it is used in projects across Europe, Asia, Australia, and the U.S.

Paleoenvironment

The formation is characterized by lagoonal facies with episodes of higher energy and rare bivalve patch reefs, such as '' Chondrodonta'' and

Rudists Rudists are a group of extinct box-, tube- or ring-shaped Marine (ocean), marine Heterodonta, heterodont bivalves belonging to the order Hippuritida that arose during the Late Jurassic and became so diverse during the Cretaceous that they were m ...

, which are found throughout the entire unit. The lower section, referred to as the ''"Zolla member"'' consists of bivalve-rich limestone, including rudists and ''Chondrodonta'', as well as foraminiferal limestone, often interbedded with dolomitized dark wackestones. In the upper part of this member, pelagic limestone with '' Pythonella'' fossils is present. The main body of the ''Aurisina Limestone'' is characterized by peritidal carbonates, with some dark laminated facies, dominated by rudists, benthic foraminifera, cyanobacteria ('' Decastronema''), and algae ('' Thaumatoporella''). The Paleoenvironment of this unit is accepted to be a succession of emerged and shallow marine carbonate platform settings, including inner lagoons, high-energy shoals, tidal channels, and rudist accumulations The complex dolomitization and silicification in the region may be linked to a

Monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in Atmosphere of Earth, atmospheric circulation and precipitation associated with annu ...

climate with alternating wet and dry periods. Comparable dolomitization occurs across the Adriatic Platform, particularly in the Middle-Lower Cenomanian. The Villaggio del Pescatore site revelated

bauxite Bauxite () is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and gallium. Bauxite consists mostly of the aluminium minerals gibbsite (), boehmite (γ-AlO(OH)), and diaspore (α-AlO(OH) ...

and coal levels in the surrounding sediment indicate a humid climate. This karst region directed most water underground, limiting surface streams. Fossils of Hadrosaurs were found in a 10-meter layer of laminated limestone within a karst depression, unlike other hadrosauroids typically preserved in fluvial or marine deposits. The site also contains remains of small crocodyliforms, fish, and crustaceans, which suggest fluctuating anoxic conditions that preserved the fossils. This depression likely functioned as a cenote, attracting animals seeking water, where some may have drowned and remained preserved in low-oxygen conditions at the sinkhole's base.

Biota

Bivalves

Cephalopoda

Crustaceans

Cnidaria

Chondrichthyes

Bony Fish

Crocodiles

Pterosaurs

Dinosaurs

Flora

Palynology of the Villaggio del Pescatore section has been studied, dominated by a few gymnosperms and several angiospermous pollen types.

Image Gallery

File:Aurisina 09.jpg, Aurisina Roman Mine File:Blocco di marmo Aurisina Fiorita.jpg, ''Aurisina Fiorita'' File:Lastre lucide di Aurisina Fiorita.jpg, Polished ''Aurisina Fiorita''

Footnotes

References

* Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. . {{DEFAULTSORT:Calcare Di Aurisina Geologic formations of Italy Santonian Stage Campanian Stage Campanian