The Campanian Ignimbrite eruption (CI, also CI eruption) was a major volcanic eruption in the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

during the late

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

, classified 7 on the

Volcanic Explosivity Index The volcanic explosivity index (VEI) is a scale used to measure the size of explosive volcanic eruptions. It was devised by Christopher G. Newhall of the United States Geological Survey and Stephen Self in 1982. Volume of products, eruption c ...

(VEI). The event has been attributed to the Archiflegreo volcano, the caldera of the

Phlegraean Fields The Phlegraean Fields (, ; ) is a large volcano, volcanic caldera west of Naples, Italy. The Neapolitan Yellow Tuff eruption (about 12ka BP) produced just 50 cubic kilometers. It is, however, one of relatively few volcanoes large enough to f ...

, located west of

Mount Vesuvius Mount Vesuvius ( ) is a Somma volcano, somma–stratovolcano located on the Gulf of Naples in Campania, Italy, about east of Naples and a short distance from the shore. It is one of several volcanoes forming the Campanian volcanic arc. Vesuv ...

under the western outskirts of the city of

Naples Naples ( ; ; ) is the Regions of Italy, regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 908,082 within the city's administrative limits as of 2025, while its Metropolitan City of N ...

and the Gulf of Pozzuoli, Italy. It was the largest explosive volcanic event in Europe in the past 200,000 years, and the largest eruption of Campi Fleigrei caldera. Estimates of the date and magnitude of the eruption(s), and the amount of ejected material have varied considerably during several centuries the site has been studied. This applies to most significant volcanic events that originated in the Campanian Plain, as it is one of the most complex volcanic structures in the world. However, continued research, advancing methods, and accumulation of volcanological, geochronological, and

geochemical Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the ...

data have improved the dates' accuracy. The most recent results by

radiocarbon Carbon-14, C-14, C or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic matter is the basis of the radiocarbon dating method pioneered by Willard Libby and coll ...

and

argon–argon dating Argon–argon (or 40Ar/39Ar) dating is a radiometric dating method invented to supersede Potassium-argon dating, potassiumargon (K/Ar) dating in accuracy. The older method required splitting samples into two for separate potassium and argon measur ...

are, respectively, 39,220 to 39,705 calendar year BP and year BP. The estimated eruptive volume in

dense-rock equivalent Dense-rock equivalent (DRE) is a volcanologic calculation used to estimate volcanic eruption volume. One of the widely accepted measures of the size of a historic or prehistoric eruption is the volume of magma ejected as pumice and volcanic ash, k ...

(DRE) is in the range of , and

tephra Tephra is fragmental material produced by a Volcano, volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, ...

has dispersed over an area of around , commonly referred to as the ash horizon Y-5. The accuracy of these numbers is of significance for marine geologists, climatologists, palaeontologists, paleo-anthropologists and researchers of related fields as the event coincides with a number of global and local phenomena, such as widespread discontinuities in archaeological sequences, climatic oscillations and biocultural modifications.

Etymology

The term ''Campanian'' refers to the

Campanian volcanic arc The Campanian volcanic arc is a volcanic arc that consists of a number of active, dormant, and extinct volcanoes in the Campania region of Italy. The Campanian volcanic arc centers on the bay of Naples and includes: * Mount Vesuvius: an active v ...

located mostly but not exclusively in the

region In geography, regions, otherwise referred to as areas, zones, lands or territories, are portions of the Earth's surface that are broadly divided by physical characteristics (physical geography), human impact characteristics (human geography), and ...

Campania Campania is an administrative Regions of Italy, region of Italy located in Southern Italy; most of it is in the south-western portion of the Italian Peninsula (with the Tyrrhenian Sea to its west), but it also includes the small Phlegraean Islan ...

southern Italy Southern Italy (, , or , ; ; ), also known as () or (; ; ; ), is a macroregion of Italy consisting of its southern Regions of Italy, regions. The term "" today mostly refers to the regions that are associated with the people, lands or cultu ...

that stretches over a

subduction zone Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second p ...

created by the convergence of the African and Eurasian plates. It should not be confused with the Late Cretaceous stage

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 ...

. The word ''

ignimbrite Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrou ...

'' was coined by New Zealand geologist Patrick Marshall from

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''ignis'' (fire) and ''imber'' (shower)) and ''-ite''. It means the deposits that form as a result of a pyroclastic eruption.

Background

Solfatara - Pozzuoli - Campania - Italy - July 11th 2013 - 20

The Phlegraean Fields ( "burning fields") caldera is a nested structure with a diameter of around . It is composed of the older Campanian Ignimbrite caldera, the younger Neapolitan Yellow

Tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock co ...

caldera and widely scattered sub-aerial and submarine vents from which the most recent eruptions have originated. The Fields sit upon a

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Apennine thrust belt. The sequence of deformation has been subdivided into three periods.

Phlegraean Periods

* The First Period, which includes the Campanian Ignimbrite Eruption, was the most decisive era in the Phlegraean Fields' geologic history. Beginning more than 40,000 years ago as the external caldera formed, subsequent caldera collapses and repeated volcanic activity took place within a limited area. * During the Second Period, the smaller ''Neapolitan Yellow

'' eruption (Neapolitan Yellow Tuff or NYT) took place around 15,000 years ago. * Eruptions of the Third Period occurred during three intervals between 15,000 and 9,500 years ago, 8,600–8,200 years ago and from 4,800 to 3,800 years ago. The structure's magma chamber remains active as there apparently are solfataras, hot springs, gas emissions and frequent episodes of large-scale up- and downlift ground deformation (

Bradyseism Bradyseism is the gradual uplift (positive bradyseism) or descent (negative bradyseism) of part of the Earth's surface caused by the filling or emptying of an underground magma chamber or hydrothermal activity, particularly in volcanic calderas. ...

) do occur. In 2008 it was discovered that the Phlegraean Fields and

have a common magma chamber at a depth of . The region's volcanic nature has been recognized since Antiquity, investigated and studied for many centuries. Methodical scientific research began in the late 19th century. The yellow tuff stone was extensively quarried for centuries, which left large underground cavities that served as aqueducts and cisterns for the collection of rain water. In 2016 Italian

Volcanologist A volcanologist, or volcano scientist, is a geologist who focuses on understanding the formation and eruptive activity of volcanoes. Volcanologists frequently visit volcanoes, sometimes active ones, to observe and monitor volcanic eruptions, col ...

s announced plans to drill a probe deep into the Phlegraean Fields several years after the 2008 ''Campi Flegrei Deep Drilling Project'' which had aimed to drill a diagonal borehole in order to bring up rock samples and install seismic equipment. The project was suspended in 2010 due to safety problems.

Eruptive sequence

The CI eruption has been interpreted as the largest volcanic eruption of the past 200,000 years in Europe. The eruption started with an intense Plinian phase, succeeded by a sequence of voluminous pyroclastic density currents with co-ignimbrite plumes. Both phases generated high eruptive columns, culminating in the widespread deposition of the Y-5 layer.

Plinian phase

The distribution of basal Plinian fallout strongly suggests that the onset of the eruption occurred in the northeastern sector of Campi Flegrei. This phase is supplied by the uppermost, most evolved trachytic magma of the chamber. A detailed attempt to reconstruct this phase through direct field measurements recognized the evolution of the Plinian column through five units of fall deposits. The eruption first reached a column height of and then peaked at , and during the latest stage, the top of the plume waned to . The entire Plinian eruption lasted about 20 hours and emitted of magma. Another attempt at reconstruction by numerical simulation shows a different Plinian process. The eruptive column rose to , and the entire phase was completed within 4 hours with a magma volume of . Plinian tephra is present in deposits to distances of at least and between and constitutes 35–45% of the Y-5 deposit.

Ignimbrite phase

The Plinian phase was followed by six main units of impressive pyroclastic density currents spreading over an area of and managing to surmount mountain ridges up to , extinguishing all life within a radius of about . The collapse of Plinian column due to an increase of the mass eruption rate produced the first ignimbrite unit, the Unconsolidated Stratified Ash Flow. Subsequently, the eruption advances into the climactic stage, generating three ignimbrite units, namely the voluminous Welded Grey Ignimbrite, Coarse Pumice Flow, and Lower Pumice Flow Unit. Collectively, these three units constitute the bulk of the CI eruption. The Y-5 co-ignimbrite ash dispersals to the southeast and northeast within of Campi Flegrei are associated with these first four units of pyroclastic density currents.

After the eruption of the first four units, the majority of the CI magma had been expelled, resulting in the collapse of the caldera. The collapse triggered a new phase of eruption of Breccia/Spatter Unit and Upper Pumice Flow Unit. The magma was sourced from the lowermost, less evolved portions of the chamber. These two units represented the last stage of eruption and were only emplaced as very proximal deposits along the caldera rim. Most of the ultra-distal dispersal > was associated with this stage. Calculations of exposed and inferred thickness and area of pyroclastic density currents yield a total ignimbrite volume of of magma. Consequently, the DRE volume of co-ignimbrite ash based on vitric loss method falls in the range of DRE. The overall magma volume expelled during this phase amounts to . Numerical simulation obtained a lower estimate of DRE for co-ignimbrite ash.

Global impact

The Ar/Ar age of the CI eruption has been determined to year BP. The ¹⁴C age of charred wood embedded in Welded Grey Ignimbrite has been calibrated to 39,220—39,705 year BP. The two ages of the CI eruption disagree on a scale of centuries, suggesting that the dating uncertainties of Ar/Ar or ¹⁴C are underestimated. Nonetheless, the temporal proximity of CI eruption,

Middle Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (disambiguation) * Middle Brook (disambiguation) * Middle Creek ...

Upper Paleolithic The Upper Paleolithic (or Upper Palaeolithic) is the third and last subdivision of the Paleolithic or Old Stone Age. Very broadly, it dates to between 50,000 and 12,000 years ago (the beginning of the Holocene), according to some theories ...

transition, Neanderthal disappearance, and the onset of Heinrich event 4 (HE-4) drew considerable scholarly attention.

Relation with Heinrich event 4

In climatostratigraphy, the CI eruption occurred near the onset of a millennial-scale cold stadial that encompassed HE-4. Francesco G. Fedele and his team postulated that the

volcanic winter A volcanic winter is a reduction in global temperatures caused by droplets of sulfuric acid obscuring the Sun and raising Earth's albedo (increasing the reflection of solar radiation) after a large, sulfur-rich, particularly explosive volcanic eru ...

of the CI eruption triggered HE-4, which saw the summer

sea surface temperature Sea surface temperature (or ocean surface temperature) is the ocean temperature, temperature of ocean water close to the surface. The exact meaning of ''surface'' varies in the literature and in practice. It is usually between and below the sea ...

plummeting by 3–6 °C along the Iberian margin and by 5 °C in the westernmost Mediterranean. However, this connection has been refuted by high-resolution paleoclimate records, which clearly indicate that the Y-5 layer postdates the onset of HE-4 by 700–800 years.

Volcanic winter hypothesis

Petrological studies show that the magma of the CI eruption contained 50–250 million tones of

sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is r ...

and is expected to have caused a severe volcanic winter on top of already cool climate of HE-4 by injecting stratospheric sulfur aerosols. Simulations of the CI eruption by the

Community Earth System Model The Community Earth System Model (CESM) is a fully coupled numerical simulation of the Earth system consisting of atmospheric, ocean, ice, land surface, carbon cycle, and other components. CESM includes a climate model providing state-of-art simu ...

find that temperature anomalies in Western Europe reach –2 °C to –4 °C during the year following the eruption, and the peak cooling and acid deposition lasted one to two years. To assess the volcanic winter using climate proxies, significant effort has been invested in directly detecting the

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

signal of the CI eruption in polar ice cores, but these attempts have turned out to be fruitless. Several large sulfate peaks occurring near the onset of HE-4 have been tentatively attributed to the CI eruption, but it requires a well-characterized tephra find in the ice cores to ensure that the sulfate peak is indeed associated with the CI.

Relation with Neanderthal disappearance

Some hypothesized that a connection may exist between the CI eruption and the disappearance of Neanderthals in Europe. It is suggested that the CI eruption triggered a bio-cultural revolution, enabling modern humans to outcompete the Neanderthals. This has been rejected based on stratigraphical evidence that the cultural transition from

Mousterian The Mousterian (or Mode III) is an Industry (archaeology), archaeological industry of Lithic technology, stone tools, associated primarily with the Neanderthals in Europe, and with the earliest anatomically modern humans in North Africa and We ...

Uluzzian The Uluzzian Culture is a transitional archaeological culture between the Middle Paleolithic and the Upper Paleolithic, found in Italy and Greece. A team led by archaeological scientist Katerina Douka has dated the Uluzzian as lasting from sh ...

or Proto-

Aurignacian The Aurignacian () is an archaeological industry of the Upper Paleolithic associated with Cro-Magnon, Early European modern humans (EEMH) lasting from 43,000 to 26,000 years ago. The Upper Paleolithic developed in Europe some time after the L ...

(indicating the replacement of Neanderthals by modern humans in archaeology) began below the CI tephra. In 2021, the timing of Neanderthal extinction has also been re-calibrated to year BP, thus predating the CI eruption.

Relation with Middle to Upper Paleolithic transition

At many European archaeological sites, Uluzzian and Proto-Aurignacian, transitional techno-complexes between the Middle and the Upper Paleolithic, are directly capped by the CI tephra. Radiocarbon dating of the Proto-Aurignacian or Uluzzian layers yielded ages statistically indistinguishable or barely older than the radiocarbon age of the CI eruption. Based on stratigraphic sequences alone, the CI eruption appeared synchronous with the end of the Proto-Aurignacian and Uluzzian cultures, and the emergence of the Early Aurignacian adaptation appeared immediately after the eruption. This has been interpreted as indicating that the impact of the CI eruption led to the abrupt end of the pre-CI lithic traditions and triggered the following Early Aurignacian revolution. However, when probability curves of boundary transition are taken into account, the Early Aurignacian culture emerged in some regions of Europe prior to the CI eruption, thus precluding the CI eruption from being the instigator of the Early Aurignacian.

Footnotes

References

External links

* * {{List of volcanoes Pre-Holocene volcanism Campanian volcanic arc Pleistocene volcanism Pleistocene Europe Prehistoric Italy History of Campania VEI-7 eruptions Events that forced the climate Volcanic eruptions in Italy Plinian eruptions Phlegraean Fields