Evaluation and archaeological potential of geophysical investigations of the Roman fort and baths in Northern Muntenia,România

The Roman fort from Sfârleanca is one of the most representative archaeological sites dating from the Roman period (2nd century A.D.) in Northern Muntenia. The existing natural and anthropic features of the environment required the application of geophysical methods in order to outline the spatial pattern of the buried remains, to define the geometry of the anthropogenic settlements and to obtain detailed information about different archaeological materials without digging. During the survey, two different geophysical methods have been employed: total magnetic field measurements and electrical resistance mapping using Twin-probe array. The instrument consists of GSM19W Overhauser magnetometers with GPS, in base-rover system, and a twin-probe array LGM 4-Point light hp. The measurements were used to draw primary maps of the physical parameters (total magnetic field strength/intensity, electrical resistance), and also processed maps (filtering, derivative). The magnetic results obtained by interpreting the anomalies yielded information about the limits of the fort, about the internal organization of the military structure (its axial road, partially its secondary road, the localization and the shape of its constructions) and at the bath and heating installation. A previously unknown element is the possible water supply pipe made of ceramic material highlighted by the mathematical modelling of the data obtained by the magnetic investigations. Electrical resistance results provide complementary information to the magnetic survey concerning the limits of the baths and the remains of the fort structure. This paper brings to light geophysical investigations into this Roman fort and baths, extending the picture produced by previous archaeological excavations that only dealt with a small part of the site. It indicates the importance of using geophysical methods in preliminary archaeological research and the advantages of combining total magnetic field measurements and electrical resistance mapping when investigating an archaeological site characterized by a number of environmental difficulties.     

Non-invasive Geophysical Surveys in Search of the Roman Temple of Augustus Under the Cathedral of Tarragona (Catalonia,Spain): A Case Study

An integrated geophysical survey has been conducted at the Tarragona’s Cathedral (Catalonia, NE Spain) with the aim to confirm the potential occurrence of archaeological remains of the Roman Temple dedicated to the Emperor Augustus. Many hypotheses have been proposed about its possible location, the last ones regarding the inner part of the Cathedral, which is one of the most renowned temples of Spain (twelfth century) evolving from Romanesque to Gothic styles. A geophysical project including electrical resistivity tomography (ERT) and ground probing radar (GPR) was planned over 1 year considering the administrative and logistic difficulties of such a project inside a cathedral of religious veneration. Finally, both ERT and GPR have been conducted during a week of intensive overnight surveys that provided detailed information on subsurface existing structures. The ERT method has been applied using different techniques and arrays, ranging from standard Wenner–Schlumberger 2D sections to full 3D electrical imaging with the advanced Maximum Yield Grid array. Electrical resistivity data were recorded extensively, making available many thousands of apparent resistivity data to obtain a complete 3D image after a full inversion. In conclusion, some significant buried structures have been revealed providing conclusive information for archaeologists. GPR results provided additional information about shallowest structures. The geophysical results were clear enough to persuade religious authorities and archaeologists to conduct selected excavations in the most promising areas that confirmed the interpretation of geophysical data. In conclusion, the significant buried structures revealed by geophysical methods under the cathedral were confirmed by archaeological digging as the basement of the impressive Roman Temple that headed the Provincial Forum of Tarraco, seat of the Concilium of Hispania Citerior Province.     

Geophysical-Archaeological Survey in Lake Tequesquitengo,Morelos, Mexico

In August 2009, a marine geophysical survey was conducted in Lake Tequesquitengo (located in the state of Morelos, Mexico) to delineate the extent of the remains of a small town that has been submerged since the mid 19th century. The survey consists of the acquisition and mapping of magnetic, single beam bathymetric and side-scan sonar data. A dual receiver marine GPS navigation system was used to position the boat during the survey. Except for the larger structural remains that are visible on the side scan sonar images, the magnetic anomaly map proved to be most useful in delineating the extent of the town. These anomalies exhibit short wavelength components in the area surrounding a submerged church, with the shortest wavelength components being confined to the area immediately east of the church. These short wavelength components are only observed near the church; therefore, we propose that they delineate the buried remnants of the submerged town.     

Integrated Geophysical Investigations at the Greek Kamarina Site (Southern Sicily,Italy)

Kamarina, located in southern Sicily (Italy), was an important Greek colony since its foundation in the sixth century BC. Archaeological excavations, carried out since the twentieth century, uncovered only limited portions of the site so far. Despite the importance of the Greek colony, the presence of remarkable buildings that archaeologists expected to bring to light has not found fully correspondence in the archaeological excavations. Consequently, the integrated geophysical prospection carried out in the study area is aimed to support and address the future archaeological investigations. After the photographic and thermographic survey obtained by an unmanned aerial vehicle, we performed a systematic survey through ground magnetic and GPR methods over an area of 6200 m². The acquisition procedures have been optimized in order to get the best results combining high resolution and elevated speed of acquisition. The results derived from the three geophysical techniques have been conveniently combined by means of a cluster analysis, allowing us to clearly identify a series of buried archaeological features. Because of their geometrical characteristics, often in good agreement with the spatial arrangement of the archaeological remains at the surface, these buried archaeological features can be interpreted as roads, walls, or buildings foundations in which the various construction phases of the city can be clearly recognized. The integrated approach has proven to be essential for a robust interpretation of the archaeogeophysical investigation.     

Geophysical Survey and Archaeological Data at Masseria Grasso (Benevento,Italy)

The use of geophysical methods in metrology is a significant tool within the wide research topic of landscape archaeology context. Since 2011, the Ancient Appia Landscapes Project aims to recognize dynamics, shapes and layout of the ancient settlement located along the Appia road east of Benevento, and cyclical elements and human activities that influenced the choice of landscapes. The integration of geophysical data with an archaeological infra-site analysis allowed us to investigate the area of Masseria Grasso, about 6 km from Benevento (Campania region, Italy). In this framework, an archaeogeophysical approach (Geomagnetic and Ground Penetrating Radar) was adopted for detecting anomalies potentially correlated with buried archaeological evidences. The geomagnetic results have given a wide knowledge of buried features in a large survey highlighting significant anomalies associated with the presence of buildings, roads and open spaces. These geophysical results permitted us to define the first archaeological excavations and, successively, a detailed Ground Penetrating Radar approach has been provided highlighting the rooms and paved spaces. The overlap between archaeological dataset and geophysical surveys has also allowed recognizing the path of the ancient Appia road near the city of Benevento and hypothesize the settlement organization of the investigated area, which has been identified with the ancient Nuceriola.     

A geophysical survey on the archaeological site of Mugardos (NW Iberian peninsula)

Archaeological indications near Mugardos (Ferrol, NW Spain) suggest the existence of a Roman settlement. In fact, in the area were found pavements, walls with north-south and east-west orientations and some structures that endured heating. These remains are covered by soil, more than 1 m thick, and lie over schists. In order to determine the archaeological potential of the area and to delimit future excavations a geophysical survey, consisting of a joint resistivity and magnetic survey, was planned and carried out. The square array of electrodes was used and the data are discussed as apparent square array resistivity maps and azimuthal inhomogeneity ratio (AIR) maps. The magnetic survey included total field measurements using sensor heights of 0.30 and 2.30 m above the ground, so that a magnetic gradient could be computed.A combined interpretation of both resistivity and magnetic data is discussed. Later excavations have confirmed the geophysical interpretation.     

Geoprospecting Survey in the Archaeological Site of <Emphasis Type="Italic">Aquinum</Emphasis> (Lazio,Central Italy)

In this paper, the results of a ground penetrating radar (GPR) prospecting survey performed in the Roman archaeological site of Aquinum are shown. The prospecting was performed in two distinct areas. The first one was close to the remains of the ancient thermal baths, where a public project intends to build a car park. The second area is close to an apsidal Roman building, and it was of interest to establish whether, and possibly up to what extent, the remains of this partially revealed structure continue, or maybe whether meaningful further structures are present.     

Fluvial response to climatic and anthropogenic forcing in the Moselle drainage basin (NE France) during historical periods: evidence from OSL dating

The aim of this paper is to study a low energy fluvial system response to natural and anthropogenic forcing during the last two millennia. In contrast with longer timescales (Holocene to Quaternary), historical sedimentary archives are sparse in such systems which are typically characterized by the predominance of erosion compared with aggradation. We studied three main sections in the Moselle valley (northeastern France) by a multi‐proxy approach combining morphology, sedimentology, archaeological evidence, historical archives, and dating. The geochronological framework was based on Optically Stimulated Luminescence (OSL) and validated by independent age control. The exposed sediments were allocated to different historical periods from Roman period to present. The first results show that, in contrast with many other fluvial systems, the Moselle and its tributaries did not experience major changes during historical periods. Climatic changes such as the Little Ice Age had a minor influence on floodplain aggradation (e.g. in grain size or sedimentation rates) in the Moselle valley and were only able to affect the fluvial style. This provides evidence that the reworking of sediments is the main fluvial process at short timescales in the valley floors of the Moselle catchment. In contrast, anthropogenic forcing seems important not only during recent centuries but also since Roman times. This is suggested by the case‐study of the Metz‐Mazelle section where significant headward erosion and sedimentation were recognized, and may be related to human occupation. The results therefore point to a need for increasing geoarchaeological and geochronological research in the Moselle catchment and similar low energy fluvial systems. Such research is actually essential to improve the knowledge of the fluvial response to environmental changes during the historical periods and to recognize the respective influence of natural variability and human forcing. Copyright © 2012 John Wiley & Sons, Ltd.     

Three-dimensional GPR study of a prehistoric site in Barbados, West Indies

Prior results of surface artifact collecting, test excavations, and auger sampling on an archaeological site in Barbados suggested that we experiment with ground-penetrating radar (GPR) as a method to target areas for future study. The site is associated with village occupations of Amerindians that are dated to between 2000 and 500 years ago. Archaeological features include burials, hearths, ceramic lined wells and postholes. Artifact middens contain pottery sherds, conch shells, and other marine resource debris. The site selected was located at the southern tip of Barbados and is situated on a deep stabilized surface behind a large active dune system. The soil layer consists of dry, clean quartz sand.We obtained limited ground truth at the site by hand auguring in areas of field-identified anomalies, and by auguring control holes away from anomalies. Anomalies were usually large diffractors such as conch shells and rocks. We used 3D visualisation software to perform standard processing enhancements and to assemble the parallel lines into three-dimensional volumes. The dimensions, distribution, and shapes of time-sliced amplitude anomalies were consistent with those of previously excavated burials, poles, and pit structures. In particular, we interpret the data as indicating the presence of a circular house structure with four center posts; this structure was previously unknown at this site. The work presented here builds upon and extends earlier excavation-based findings at this site, and will allow for better-focused excavations in the future.     

High resolution 3D ERT to help GPR data interpretation for researching archaeological items in a geologically complex subsurface

Muro Leccese (Lecce) contains one the most important Messapian archaeological sites in southern Italy.The archaeological interest of the site arises from the discovery of the remains of Messapian walls, tombs, roads, etc. (4th–2nd centuries BC) in the neighbourhood. The archaeological remains were found at about 0.3 m depth.At present the site belongs to the municipality, which intends to build a new sewer network through it. The risk of destroying potentially interesting ancient archaeological structures during the works prompted an archaeological survey of the area. The relatively large dimensions of the area (almost 10,000 m²), together with time and cost constraints, made it necessary to use geophysical investigations as a faster means to ascertain the presence of archaeological items. Since the most important targets were expected to be located at a soil depth of about 0.3 m, a ground-penetrating radar (GPR) survey was carried out in an area located near the archaeological excavations. Unfortunately the geological complexity did not allow an easy interpretation of the GPR data.Therefore a 3D electrical resistivity tomography (ERT) scan was conducted in order to resolve these interpretation problems.A three-way comparison of the results of the dense ERT measurements parallel to the x axis, the results of the measurements parallel to the y axis and the combined results was performed.Subsequently the synthetic model approach was used to provide a better characterization of the resistivity anomalies visible on the ERT field data.The 3D inversion results clearly illustrate the capability to resolve in view of quality 3D structures of archaeological interest. According to the presented data the inversion models along one direction (x or y) seems to be adequate in reconstructing the subsurface structures.Naturally field data produce good quality reconstructions of the archaeological features only if the x-line and y-line measurements are considered together. Despite the increased computational time required by the 3D acquisition and 3D inversion schemes, good quality results can be produced.     

3-D high-resolution multi-channel radar investigation of a Roman village in Northern Italy

A fast and efficient subsurface radar imaging procedure, based on a multi-channel cart system, has been developed and tested within the framework of a large-scale archaeological investigation project in northern Italy.The tested cart comprises 14 closely-spaced dipoles, rotated by 45° with respect to the dragging direction, and allows unidirectional scanning operations. Using this approach, an area of approximately 75 000m² was surveyed daytime via recording of a dense grid of about 490km of radar profiles. Geo-referencing of the scanning trajectories was achieved operating a separate on-board differential Global Positioning System in real-time kinematic mode. In this configuration the final positioning error of the radar sweeps was less than 0.05m.The large amount of collected data, of the order of tens of GBytes, was processed, using an open-source software package, on a workstation-based environment. A set of specific codes was developed to fully automate the data processing and the image generation procedure. Critical steps during code development were the integration of positioning and radar data, the referencing of the single radar sweeps and the correction for changes in the spectral amplitude of the different channels.The processed data volume displays high signal coherency and reveals several well-defined reflectors, clearly visible both on vertical profiles and horizontal time slices. The plan of the Roman settlement could be revealed in detail proving the potential of the tested approach for assisting high-resolution archaeological investigations of large areas.     

GPR prospection in ancient Ephesos

Urban area of ancient Ephesos (present Turkey) is too large to be fully excavated, so geophysical prospection and mapping can help with the investigation. Georadar is one of the most effective tools for it. Two different tasks solved by georadar are presented. The first problem was the interconnection between the city and the temple of Artemis. By historical records, it was made by two sacred procession roads, which had character of Graeco–Roman stoa, i.e., a roofed road. Only small parts of these roads were discovered in ruins or excavated. Some hundreds of metres from total length of a few kilometres became known, but the questions above were not solved. Then, the area was prospected by georadar. Series of GPR lines were scanned gradually from the last known points and evaluated right on the spot. As a result, a plan of georadar indications could be drawn. These indications created two lines tracing unknown parts of both roads joining together and then continuing till the entry of the temple. The results were confirmed by two boreholes. The second task was mapping of Hellenistic level of Tetragonos agora. At present, it is under the Roman level, and is visible only in some excavation pits. About a half the square was covered by detailed georadar survey. Numerous anomalies indicated presence of underground objects. Compared with the results of excavations, they were interpreted as ancient remains in several levels. Then plans of these indications were compiled for separated levels. Hellenistic buildings remains were mapped, forming an older agora, smaller and slightly different by its shape from the Roman building plan. Besides it, uncovered parts of Roman ruins were detected, as well as some remains of Classic and Archaic settlement levels. Some traces of even older human presence were found under them. Georadar results will serve as a guideline for future excavations.     

Coseismic Damage at an Archaeological Site in Sicily,Italy: Evidence of Roman Age Earthquake Surface Faulting

Archaeoseismology can provide a useful chronological tool for constraining earthquakes and documenting significant evidence that would otherwise be lost. In this paper, we report a case of surface faulting on ancient man-made structures belonging to the archaeological site of Santa Venera al Pozzo situated along the eastern flank of Mt. Etna volcano in eastern Sicily (southern Italy), which is affected by well-developed tectonic faults. Geological surveys highlight a set of fractures affecting the archaeological ruins, suggesting the occurrence of a capable fault zone across the area. An integrated geophysical survey was carried out in order to identify the main subsurface tectonic discontinuity ascribable to the fault zone. The information derived from different geophysical techniques, such as electrical resistivity tomography, seismic refraction tomography, ground-penetrating radar, and magnetic surveys allowed us to infer that the fractures observed at the surface could have been produced by coseismic rupture. They are conceivably linked to a strong earthquake that probably occurred in the Roman period, around mid-end of the third-century AD; time constraints are inferred through the dating of buildings of the archaeological site.     

Recent Aeolian Origin of Surficial Gypsum Crusts in Southern Tunisia: Geomorphological,Archaeological and Remote Sensing Evidence

Recent quarring of the surficial gypsum crusts adjacent to Djebel Sidi Bou Hellas has revealed sections typically showing a discontinuous surface gravel cover underlain by more than 7 m of microcrystalline gypsum. The location, elongate shape, form in cross-section and chemistry of this deposit suggests an aeolian origin, whereby aeolian sands have been trapped against a glacis d'erosion terrace, and subsequently consolidated by meteoric waters. One gypsum quarry revealed a midden and the remains of a Roman dwelling now buried within the crust. A radiocarbon date of organic matter in the midden and a Roman coin found within it suggest an age of AD324–345 for the deposit. This is the first firm date for a surficial gypsum crust in southern Tunisia and the age is surprisingly young. Previous studies have speculated on phases of crust development between the Villefranchian and early Holocene but none since. Remote sensing and field evidence show that gypsiferous sands are currently deflated from the dry parts of the mudflats of Chott Fedjaj. They are subsequently transported in a southwesterly trajectory and trapped against glacis on the southern margins of Chott Fedjaj, forming contemporary analogues of the Roman deposit. Sands that are not trapped form dune fields and sandflats where gypsum crusts appear to be forming today. If the source area of gypsum sands has remained constant since Roman times, then the predominant wind direction has moved 45° to the southwest since then. The other possible source of aeolian gypsum for the Roman deposit, the vast mudflats of Chott Djerid, involves an even greater change in predominant wind direction. © 1997 John Wiley & Sons, Ltd.     

Magnetic study of archaeological structures in La Campana,Colima, western Mesoamerica

Results of a magnetic survey of the archaeological site at La Campana in the Colima area of western Mesoamerica are reported. The site is located in the northern suburbs of the city of Colima over a terrain characterized by volcanic debris avalanche deposits. The study area of about 12,600 m² is divided into two sections corresponding to (1) the main archaeological site and to (2) a potential extension north of it. The magnetic survey shows the presence of three large dipolar anomalies oriented N–S or NNE–SSW occurring over small hills some 2 to 4 m high. The archaeological excavations have uncovered three large structures made mainly of rounded volcanic boulders built on large platforms. The southern structure consists of a pyramid (25×25 m² at its base) and an adjacent structure (at least 30×15 m²). The central structure is a pyramid (20×20 m²) with stair-like accesses on either side. The northern structure is a large complex extending over an area at least 40×30 m². A detailed survey in the open plaza area, using the vertical gradient method, revealed an elongated shallow linear feature, which turned out to be part of a channel network constructed with flat volcanic slabs. Inverted conical openings that end in a small well are connected to the channel network, which was apparently designed to collect water from rain and distribute it to the surrounding structures. The magnetic survey also shows the occurrence of a dipolar anomaly over a small topographic elevation that may likely correspond to another large pyramid. North of it, there is a series of elongated anomalies similar in shape and amplitude to those associated with the hydrological network. The archaeological remains extend over an area considerably larger than the one excavated in the archaeological study. The characteristics and size of the pyramidal structures, the plazas and channel network, and the apparent overall extension of the archaeological site strongly suggests that La Campana constituted a major urban and ceremonial center in westernmost Mesoamerica.     

Roman literary and epigraphic sources for the study of historical seismicity in Algeria circa 42–420 ad

The seismicity of Algeria since the nineteenth century is relatively well documented. However, compared with the numerous damaging earthquakes that are documented since 1850, fewer than a dozen reports of earthquakes are listed for the pre-1850 ad period, suggesting that the historical record is missing a substantial number of earthquakes. This paper examines the use of literary and epigraphic sources relevant to the investigation of seismicity in Algeria during Roman times. We provide examples where the meager written literary record may be supplemented with appropriate archaeological and epigraphic data describing damage to ancient Roman sites. The examples show that collaboration between earth scientists and archeologists is of utility in improving the seismic record and highlights the need for further study of data sources and repositories located both inside and outside of Algeria.     

Archeoseismic study of damage in Roman and Medieval structures in the center of Cologne, Germany

The causes of damage observed in archeological records or preserved monuments are often difficult to be determined unequivocally, particularly when the possibility of secondary earthquake damage exists. Such secondary damage has been previously proposed for the Roman Praetorium, the governor’s palace in the center of Cologne. Ongoing excavations since 2007 revealed additional damage. The existing ground that has been uncovered and documented extends the affected area to 175?×?180 m. We present a comprehensive virtual model of the excavation area based on 200 3D laserscans together with a systematic analysis of the damage patterns and an improved model of the terrain during Roman/Medieval times including geotechnical parameters of the subsurface. Five locations with different damage patterns, including a Roman sewer, the octagonal central part of the Praetorium, a section with strongly inclined massive walls, a 13 m deep deformed well, a collapsed hypocaust, and damages in the Medieval mikveh are analyzed in detail. We use site-specific synthetic strong ground motion seismograms to test the possibility of earthquake-induced ground failures as a cause for the observed damage. This subsurface model is also used to test the possibility of hydraulically-induced damages by seepage and erosion of fine-grained material from stray sand. Heavy rainstorms can induce a direct stream of surface water through the fine sand layers to the ground water table. Simulated ground motion for assumed worst-case earthquake scenarios do not provoke slope instability at the level necessary to explain the structural damages.     

Geophysical prospection,archaeological excavation,and dating in two Hellenic pyramids

Geophysical prospection employing magnetometry and electromagnetic measurements has been applied in and around two small sized pyramids of Hellenikon and Ligourio in Argolid, Greece. The magnetic anomalies appropriately assessed were interpreted as possible archaeological targets. Subsequent test excavations revealed the presence of room foundations and parts of walls, as well as a plethora of ceramic ware. Typological study of the ceramics classified them to as early as the proto-Helladic period and to as late as the first centuries A.D. The earlier periods have been also confirmed by a novel application of thermoluminescence (TL) dating of ceramics and the megalithic stones themselves. The present results question earlier attempts classifying these pyramids at the Classical period and favour much earlier periods.     

Review paper: Exploration geophysics for intrusion‐hosted rare metals

Igneous intrusions, notably carbonatitic–alkalic intrusions, peralkaline intrusions, and pegmatites, represent significant sources of rare‐earth metals. Geophysical exploration for and of such intrusions has met with considerable success. Examples of the application of the gravity, magnetic, and radiometric methods in the search for rare metals are presented and described. Ground gravity surveys defining small positive gravity anomalies helped outline the shape and depth of the Nechalacho (formerly Lake) deposit within the Blatchford Lake alkaline complex, Northwest Territories, and of spodumene‐rich mineralization associated with the Tanco deposit, Manitoba, within the hosting Tanco pegmatite. Based on density considerations, the bastnaesite‐bearing main ore body within the Mountain Pass carbonatite, California, should produce a gravity high similar in amplitude to those associated with the Nechalacho and Tanco deposits. Gravity also has utility in modelling hosting carbonatite intrusions, such as the Mount Weld intrusion, Western Australia, and Elk Creek intrusion, Nebraska. The magnetic method is probably the most successful geophysical technique for locating carbonatitic–alkalic host intrusions, which are typically characterized by intense positive, circular to sub‐circular, crescentic, or annular anomalies. Intrusions found by this technique include the Mount Weld carbonatite and the Misery Lake alkali complex, Quebec. Two potential carbonatitic–alkalic intrusions are proposed in the Grenville Province of Eastern Quebec, where application of an automatic technique to locate circular magnetic anomalies identified several examples. Two in particular displayed strong similarities in magnetic pattern to anomalies accompanying known carbonatitic or alkalic intrusions hosting rare‐metal mineralization and are proposed to have a similar origin. Discovery of carbonatitic–alkalic hosts of rare metals has also been achieved by the radiometric method. The Thor Lake group of rare‐earth metal deposits, which includes the Nechalacho deposit, were found by follow‐up investigations of strong equivalent thorium and uranium peaks defined by an airborne survey. Prominent linear radiometric anomalies associated with glacial till in the Canadian Shield have provided vectors based on ice flow directions to source intrusions. The Allan Lake carbonatite in the Grenville Province of Ontario is one such intrusion found by this method. Although not discovered by its radiometric characteristics, the Strange Lake alkali intrusion on the Quebec–Labrador border is associated with prominent linear thorium and uranium anomalies extending at least 50 km down ice from the intrusion. Radiometric exploration of rare metals hosted by pegmatites is evaluated through examination of radiometric signatures of peraluminous pegmatitic granites in the area of the Tanco pegmatite.     

The Albano maar lake (Colli Albani Volcano, Italy): recent volcanic activity and evidence of pre-Roman Age catastrophic lahar events

The evaluation of volcanic hazard in the Roman hinterland related to the quiescent Colli Albani Volcano has recently been the subject of renewed attention and several interpretations by many authors. However, very little was known of the recent history of the volcano, making such interpretations rather speculative. The most recent activity of Colli Albani Volcano originated from the Albano polygenetic maar lake, which erupted several phreatomagmatic units, the most recent of which, the Peperino Albano ignimbrite, has been dated at around 25 ka. An area of several square kilometers centered around Albano Lake is presently the site of shallow and frequent seismic activity and gaseous emission as well as hydrothermal activity and is therefore considered the most prone to geologic hazards. This paper presents new stratigraphic and geomorphologic data as well as age determinations that allow rejuvenation of the most recent activity of the Colli Albani Volcano, and particularly the Albano maar lake, to the Holocene. This study allows for the first time to identify a potential hazard related to the Albano maar lake withdrawal interpreted to be related to endogenous causes, namely CO₂ emission. The main results of the study are: (1) the Peperino Albano is not, as is generally believed, the last phreatomagmatic eruption from the Colli Albani Volcano; a previously unrecognized phreatomagmatic surge deposit has been identified overlying the paleosol at the top of the Peperino Albano and related lahar deposits; (2) two lahar deposits separated by paleosols top the stratigraphic succession and are dispersed only to the NW, corresponding to the lowest point of the maar rim, indicating that catastrophic hydrologic events occurred at the Albano Lake in recent times; rapid and substantial lake-level variations and lake withdrawal are reported by Roman historians and recorded by the stratigraphy of the Albano Lake lacustrine sediments; (3) microfracturing related to seismic energy release is linked to sudden variation of CO₂ flow and upwelling of hydrothermal fluids. These occurrences across the lake are the likely causes that triggered during Holocene several episodes of lake withdrawal, rising the water table and probably triggering convective rollover of the lake water.