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In this paper we describe the structural architecture of the Colli Albani from the sedimentary cover to the upper mantle. The regional stratigraphy, deep wells and sedimentary xenoliths embedded in the pyroclastic deposits have been considered in order to constrain the composition and structure of the sedimentary substratum, whereas the lithospheric structure of the volcano has been investigated using seismic tomography and receiver function analyses. The main features at depth are a sub-horizontal Moho located at 20 – 24 km and a low velocity in the uppermost mantle. The Moho separates two anisotropic regions, one located in the uppermost mantle and a second in the lower crust. The anisotropic fabric can be interpreted as being due to a sub-vertical flux in the mantle coherent with the magma uprise from a mantle source. Seismolo- gical analyses do not discriminate velocity reductions ascribable to melt in the shallow crust. An intrusive body, which up-domed the limestone layer, is present beneath the central part of the volcano at depths greater than 5 km. These data are in agreement with the position of the magma chamber deduced by the presence of thermo-metamorphic xenoliths related to dolostone and limestone protolithes, which represent the lowermost portion of the Mesozoic – Cenozoic sedimentary sequence

The polygenetic Albano maar is the most recent centre of the Colli Albani volcano. Phreatic activity at the maar occurred throughout the Holocene. This paper summarises the close relationships between the activity of the maar and the history of settlement in the Roman region. Repeated lahars associated to the lake overflows occurred along the northwestern slope of the maar. The last catastrophic overflow occurred in 398 B.C.E., after which the Romans exca- vated a 1.5 km long drain-tunnel through the maar crater wall, which has since kept the lake 70 m below the lowest point of the rim. This tunnel drain may be regarded as the first construction made to mitigate a volcanic hazard in history. The surprising and still largely unknown results of this study are very important to understand the history of settlement of the area and to assess the hazard of the Roman region.

The eastern part of the suburbs of Rome up to the Alban Hills was the focus of extensive archaeological investigations that demonstrated the presence of recent/fi nal Neolithic and Eneolithic settlements as well as of numerous Eneolithic necropolises. Geological studies led to a revision of our understanding of Holocene primary volcanic deposits and lahar fl ows coming from the crater of the Alban Lake. The lack of early Neolithic settlements where lahar deposits occur in the investigated area agrees with the dates taken immediately below the most impressive lahar deposits, which are referable to a period corresponding to the recent/fi nal Neolithic. Geological and palaeoenvironmental investigations are currently being carried out with the aim of identifying the extent of the lahar fl ows as well as the timing and the modes of the occupation of the territory immediately above these. These studies are linked to a study of the variations in the vegetation during the Neolithic and the Eneolithic

""High-energy seismicity is historically recorded in Tripolitania, Libya suggesting that. this area, far from Mediterranean convergent margin, is currently deforming. How this deformation. relates to surrounding tectonics of the Africa-Europe convergence is still poorly known. Here, we. use remote sensing image analysis and structural survey to show the recent deformation history that. affected Tripolitania and reactivated the western bordering structures of Sirte Basin. This tectonic. regime onset long after the Paleocene–Oligocene deformation correlated to the Hellenic subduction. evolution (Libyan tectonics have been quiescent since then) and is compatible with age and. trends of the Sicily Channel rift zone, a deformational belt that developed across the Maghrebian. chain. We show that the continuity of this belt reaches farther than that previously acknowledged,. as far as c. 1400 km from the collisional front. We speculate on the causes of deformation in this. remote area, suggesting that the extensional belt formed in response to the strong slab-pull gradients. at the central Mediterranean subduction margin which followed the progressive closure of the. oceanic basin.""

Trioctahedral mica crystals are frequently found in the volcanoclastic products emplaced during the final stages of the activity of the Colli Albani volcano (Roman Region, central Italy). In the youngest phreatomagmatic deposits, mica is found either as a minor mineral phase in holocrystalline ejecta, scoriae, and coherent pyroclastics, or as loose phenocryst in incoherent pyroclastics. Based on optical and electron microscope investigations, as well as crystal chemical and structural data, the micas selected for this study were divided into two groups, the first one encompassing brownish, Fe-rich crystals (type-A phlogopites, hereafter referred as t-A) with 0.68 < Mg/(Mg + Fetotal) < 0.85 and 0.062 < Tiapfu < 0.199, and the other one encompassing colorless, Mg-rich crystals (type-B phlogopites, hereafter referred as t-B) with Mg/(Mg + Fetotal) in excess of 0.85 and 0.007 < Tiapfu < 0.052. t-A phlogopites also show a tetrahedral ring cavity, overlapped tetrahedral hexagon area, and basal tetrahedron area greater than in the t-B phlogopites. From a petrological point of view, the textural and chemical variations of t-A phlogopites are compatible with fractional crystallization processes taking place within the magma chamber. t-B phlogopites show evidence of a Ti-oxy substitution mechanism, thus suggesting high fO2 conditions. Textural and paragenetic features observed in t-B phlogopite-bearing rock samples, indicate a genesis by thermal metamorphism of a siliceous dolomitic limestone with the input of a variable amount of a potassic magma, possibly the same from which the t-A phlogopites formed, with the exception of one sample, for which a different parental magma is suggested. Indeed, there is an almost continuous spectrum of crystal-chemical and structural parameters starting from t-B and evolving towards t-A phlogopites. The t-A phlogopites displays complex, apparently meaningless relationships in their crystal-chemical parameters, thus indicating interplay of several substitution mechanisms. They possibly formed in polybaric conditions, since their cell volumes differ, but the total size of the cations hosted in the octahedral sheet is the same.

The historical site of the Monte Mario lower Pleistocene succession (Rome, Italy) is an important marker of the Pliocene/Pleistocene boundary. Recently, the Monte Mario site was excavated and restudied. A spectacular angular unconformity characterizes the contact between the Monte Vaticano and the Monte Mario formations, which marks the Pliocene/Pleistocene boundary. Biostratigraphical analyses carried out on ostracod, foraminifer, and calcareous nannofossil assemblages indicate an Early Pliocene age (topmost Zanclean, 3.81–3.70 Ma) for the underlying Monte Vaticano Formation, whereas the Monte Mario Formation has been dated as early Pleistocene (Santernian, 1.66–1.59 Ma). Palaeomagnetic analyses point to C2Ar and C1r2r polarity chrons for the Monte Vaticano and the Monte Mario formations, respectively. The Monte Mario Formation consists of two obliquity-forced depositional sequences (MM1 and MM2) characterized by transgressive systems tracts of littoral marine environments at depths, respectively, of 40–80 m and 15–20 m. The data obtained from foraminifer and ostracod assemblages allow us to reconstruct early Pleistocene relative sea-level changes near Rome. At the Plio/Pleistocene transition, a relative sea-level drop of at least 260 m occurred, as a result of both tectonic uplift of the central Tyrrhenian margin and glacio-eustatic changes linked to early Pleistocene glaciation (Marine Isotope Stage 58).

Il progressivo aggravarsi della stabilità di alcuni edifici eretti nel settore sud orientale di Roma lungo Viale Giustiniano Imperatore intorno ai primi anni cinquanta, ha determinato il verificarsi di un progressivo peggioramento delle condizioni di sicurezza che ha portato l'Amministrazione Comunale di Roma ad emettere, nel novembre 2001 e nel novembre del 2004 ordinanze di sgombero per alcune famiglie residenti in edifici considerevolmente lesionati a causa di cedimenti strutturali. Si è, di conseguenza, resa necessaria l'attivazione di una procedura d'urgenza per consentire una soluzione definitiva e di qualità per i residenti trasferiti, attraverso la predisposizione di un programma di interventi attuato in un quadro generale di sostenibilità e compatibilità urbanistica con le ovvie finalità di interesse pubblico. L'ambito Giustiniano Imperatore rappresenta un caso emblematico; un'area che necessita di significativi provvedimenti di riqualificazione urbana che non si limitino ad una generale riorganizzazione e migliore dotazione delle aree e servizi pubblici, ma che contemplino anche la possibilità di intervenire sistematicamente con processi di sostituzione edilizia sull'intero sistema insediativo. Dal 2000, il Dipartimento di Scienze Geologiche dell'Università "Roma TRE", chiamato dall'Amministrazione Comunale, effettua studi a carattere geologico - tecnico indirizzati alla comprensione delle dinamiche che hanno reso così "vulnerabile" questo territorio. Il presente lavoro riassume l'analisi delle componenti geologiche, idrogeologiche e geologiche-tecniche e di alcune componenti del tessuto urbano, la cui conoscenza è necessaria ai fini della progettazione degli interventi di tutela monitoraggio e sostituzione edilizia. During the early 50s, the stability of some buildings of "Viale Giustiniano Imperatore" in south-eastern Rome was rapidly growing worse. This started an urban housing emergency that in November 2001 and November 2004 led the local Administration to force some resident families to move out of their homes. As a matter of fact, structural settlement had seriously damaged many buildings. The situation called for a quick procedure that would give transferred residents a quality and definitive solution. A programme of housing projects was realized with an eye to urban sustainability and compatibility for the area, as well as to coherence with public interests. The "Giustiniano Imperatore" case is emblematic: the area needs significant urban retrofitting, which should not be limited to a general reorganization with better facilities and public services, but would also include a building replacement plan for the entire area. Since the year 2000, the Department of Geological Sciences of the University of "Roma Tre" has been charged by the local administration of the city of Rome with geological and technical studies aimed to understanding the phenomena that made this territory so vulnerable. This paper summarizes the analysis of geologicaltechnical issues and some urban texture issues, whose knowledge is mandatory for protection, monitoring, and building replacement plans.

Il progressivo aggravarsi della stabilità di alcuni edifici eretti nel settore sud orientale di Roma lungo Viale Giustiniano Imperatore intorno ai primi anni cinquanta, ha determinato il verificarsi di un progressivo peggioramento delle condizioni di sicurezza che ha portato l'Amministrazione Comunale di Roma ad emettere, nel novembre 2001 e nel novembre del 2004 ordinanze di sgombero per alcune famiglie residenti in edifici considerevolmente lesionati a causa di cedimenti strutturali. Si è, di conseguenza, resa necessaria l'attivazione di una procedura d'urgenza per consentire una soluzione definitiva e di qualità per i residenti trasferiti, attraverso la predisposizione di un programma di interventi attuato in un quadro generale di sostenibilità e compatibilità urbanistica con le ovvie finalità di interesse pubblico. L'ambito Giustiniano Imperatore rappresenta un caso emblematico; un'area che necessita di significativi provvedimenti di riqualificazione urbana che non si limitino ad una generale riorganizzazione e migliore dotazione delle aree e servizi pubblici, ma che contemplino anche la possibilità di intervenire sistematicamente con processi di sostituzione edilizia sull'intero sistema insediativo. Dal 2000, il Dipartimento di Scienze Geologiche dell'Università "Roma TRE", chiamato dall'Amministrazione Comunale, effettua studi a carattere geologico - tecnico indirizzati alla comprensione delle dinamiche che hanno reso così "vulnerabile" questo territorio. Il presente lavoro riassume l'analisi delle componenti geologiche, idrogeologiche e geologiche-tecniche e di alcune componenti del tessuto urbano, la cui conoscenza è necessaria ai fini della progettazione degli interventi di tutela monitoraggio e sostituzione edilizia. During the early 50s, the stability of some buildings of "Viale Giustiniano Imperatore" in south-eastern Rome was rapidly growing worse. This started an urban housing emergency that in November 2001 and November 2004 led the local Administration to force some resident families to move out of their homes. As a matter of fact, structural settlement had seriously damaged many buildings. The situation called for a quick procedure that would give transferred residents a quality and definitive solution. A programme of housing projects was realized with an eye to urban sustainability and compatibility for the area, as well as to coherence with public interests. The "Giustiniano Imperatore" case is emblematic: the area needs significant urban retrofitting, which should not be limited to a general reorganization with better facilities and public services, but would also include a building replacement plan for the entire area. Since the year 2000, the Department of Geological Sciences of the University of "Roma Tre" has been charged by the local administration of the city of Rome with geological and technical studies aimed to understanding the phenomena that made this territory so vulnerable. This paper summarizes the analysis of geologicaltechnical issues and some urban texture issues, whose knowledge is mandatory for protection, monitoring, and building replacement plans.

Recenti lavori per la costruzione, nella città di Roma, del Passante a Nord-Ovest (Galleria Giovanni XXIII) hanno permesso di raccogliere nuovi dati circa la stratigrafia e l’assetto tettonico del settore dei Monti della Farnesina, in riva destra del F. Tevere. Le gallerie naturali del Passante a Nord-Ovest hanno attraversato la successione plio-pleistocenica di Monte Mario, che è stata suddivisa in due formazioni: la formazione di Monte Vaticano e la formazione di Monte Mario. Quest’ultima, poggiante in discordanza stratigrafica al disopra della formazione di Monte Vaticano (Marne Vaticane Auct.), è stata distinta in cinque membri: 1) Limi di Farneto; 2) Sabbie grigie ad Arctica islandica; 3) Sabbie gialle con panchina; 4) Sabbie gialle con intercalazioni limose; 5) Argille, sabbie e limi con Cerastoderma. La forte troncatura erosiva osservata al top della formazione di Monte Vaticano suggerisce la presenza di un’ampia lacuna stratigrafica erosivo-deposizionale, tra questa e i soprastanti depositi della formazione di Monte Mario. Le analisi biostratigrafiche e paleoecologiche condotte in questo studio hanno messo in evidenza differenze sostanziali tra la formazione di Monte Vaticano (Marne Vaticane Auct.) e i soprastanti Limi di Farneto. Le Marne Vaticane Auct. campionate lungo il Passante a Nord-Ovest hanno fornito associazioni di plancton calcareo riferibili allo Zancleano inferiore (3.85-3.58 Ma). L’analisi paleoecologica condotta sulle ostracofaune indica, per le Marne Vaticane Auct., un ambiente batiale superiore, con paleoprofondità comprese tra –200 e –350 m. Per quanto emerso dall’analisi dei nannofossili calcarei, i Limi di Farneto sono collocabili al disopra della FO di medium Gephyrocapsa (Santerniano inferiore). Inoltre, per la sostanziale assenza di C. macintyrei e per la presenza di B. etnea, è possibile limitare l’età dei Limi di Farneto all’interno dell’intervallo 1,60-1,49 Ma (Santerniano superiore). L’analisi paleoecologica dell’orizzonte basale dei Limi di Farneto ha fornito indicazioni di un ambiente infralitorale esterno, con paleoprofondità di circa –40 m e un abbassamento relativo del livello del mare di almeno 160 m. Tale abbassamento relativo ha un’origine prevalentemente tettonica, dal momento che le Marne Vaticane Auct. risultano interessate da sistemi di faglie estensionali suturate dalla soprastante formazione di Monte Mario. All’interno della formazione di Monte Mario, l’analisi paleoecologica condotta sulle ostracofaune ha consentito di riconoscere due diverse sequenze deposizionali, separate da una superficie di discontinuità, legata ad un momento di abbassamento relativo del livello del mare, che definisce il limite Sabbie gialle con panchina\Sabbie gialle con intercalazioni limose. La base delle Argille, sabbie e limi con Cerastoderma corrisponde ad un secondo evento trasgressivo, riconosciuto all’interno della formazione di Monte Mario, che ha portato alla deposizione di argille marine di ambiente infralitorale, come la base dei Limi di Farneto, caratterizzate, ancora, dalla presenza di medium Gephyrocapsa. L’analisi strutturale e le indicazioni del fabric magnetico, indicano che l’alto di Monte Mario si è strutturato in due fasi tettoniche estensionali distinte: 1) una prima fase, sviluppata su piani NE-SW, collocabile prima della deposizione della formazione di Monte Mario (pre Santerniano superiore); 2) una seconda fase sviluppata su piani NW-SE, in un intervallo temporale compreso tra 750-600 ka. Infine, i caratteri paleomagnetici delle formazioni di Monte Mario e di Monte Vaticano mostrano componenti di polarità inversa ben definite, attribuite sulla base dei dati biostratigrafici, rispettivamente, all’epoca MATUYAMA ed alla parte superiore dell’epoca GILBERT.

The polygenetic Albano maar is the most recent centre of the Colli Albani volcano, located just few kilometres to the south-east of Roma. Presently the maar hosts a 167.5 m deep crater lake, the deepest in Europe. The maar is to be considered quiescent, as phreatic activity is documented throughout the Holocene. This paper illustrates the close relationships between the activity of the maar and the history of settlement in the Roman region as recorded in the geology, archaeology, history and legends of the area. Severe fluctuations of the groundwater table and catastrophic overflows of the Lake Albano from the maar rim had occurred prior to and after the early prehistoric settlements dated in the maar area at the Eneolithic times (ca. III millennium B.C.). Repeated lahars occurred along the northwestern slope of the maar filling in the paleodrainage network and forming a vast plain. Paleohydraulic analyses on fluvial and lahar deposits originated from the Holocene phreatic activity of the Albano maar indicate sediment–water flows in excess of hundreds of cubic metres per second. Absolute age determinations of the paleosoil underlying one of the most recent deposits of the lahar succession at 5800 ± 100 yr B.P. (14C CAL) are in perfect agreement with the age of the overlying Eneolithic age settlements. The last catastrophic overflow is described in the Roman literature as a consequence of the anger of Poseidon against the Romans in 398 B.C. for their war against the Etruscans. In 394 B.C. the Romans decided to prevent the repetition of such events by the excavation through the maar crater wall of a 1.5 km long drain tunnel, which is still operational, keeping the lake 70 m below the lowest point of the maar rim. This tunnel drain may be regarded as the first prevention device for volcanic hazard in history and shows an unprecedented development of the engineering technology under the pressure of hazard perception. The surprising and still largely unknown results of this study are very important to redefine the hazard of the Roman region.

The City of Rome is located in an area where long human activity and continuous transformation of the original terrain are tangible. The hydrographic networks of the Tiber's right and left banks have been modified more than once during historical times. Sometimes it has even been obliterated by urban growth (Capelli, G.,1999), so that today it is very hard, at least in the historical centre's area, to recognize the original terrain. Many of Rome’s streets run along the ancient courses of the Tiber's tributaries and many buildings lie upon alluvial deposits now buried by anthropogenic debris. Many structures overlying alluvium and debris have been damaged by subsidence and effects are visible in the buildings' uniform or differential settlement. In past, the alluvial deposits were considered as continuous bodies made of clayey-silty, sometimes sandy sediments. Instead, the formations are mainly heterogeneous and, as it will be made clear in this paper, consist of many facies (Kiersch, G.A,,1995). The geotechnical characterization of those units is mandatory for evaluating the geological environment's intrinsic hazard in urban areas, where the risk can reach very high values. This study has been carried out through the analysis of borehole and geotechnical data from three left-bank tributaries of the Tiber River the “Fosso del Velabro”, “Marrana della Caffarella”, “Fosso di Grotta Perfetta” and three right-bank tributaries (“Valle dell’Inferno”, a tributary stream of the “Fosso dei Tiradiavoli”, and the “Fosso della Maglianella”). Data about the Tiber’s alluvial deposit from various parts of the city were also included. Based on the geotechnical analysis, we created, for each deposit, a subdivision into lithotechnical units to make correlations and comparisons among the different deposits. The same level of detail has not been possible for all the stream valleys, since it is not always possible to obtain geotechnical data. Nonetheless, it is always been possible to define a stratigraphic series that would represent the examined deposit by subdividing it into units after stratigraphical and sedimentological observations.