Ice-related Landfoms in Danielson Crater, Arabia Terra region, Mars

This paper describe the ice-related landforms investigated within Danielson crater, a Martian deep crater which is centered at about 7°W and 8°N, in the region of southwestern Arabia Terra about 775 km south of Becquerel crater. A morphological and morphometric survey of the study area through an integrated analysis of the available Mars images was carried out. The morphological features of the landforms were analyzed through an integrated analysis of Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) data. In addition, a DTM of the study area within the Danielson crater was built using two stereo pair HiRISE images. Different landforms interpreted as due to ice-related processes was observed in the study area. The landforms investigated resemble similarly ice-related landforms that can be observed both in the cold region on the Earth, and in other region of Mars. The analysis carried out seem to indicate the presence of landforms attributed to the presence of ground ice and ice-melting processes which can reflect significantly climatic changes and different climatic conditions than those existing now. Moreover, they appear to display young erosional age, suggesting that are quite young, probably of middle-late Amazonian age

Evolutionary Models of the Cenozoic Basins of Central-Western Mediterranean Area: A Review of Methodological Approaches

In the last 40 years, several models based on very different methodological approaches have been proposed to interpret the complex geodynamic evolution of the central-western Mediterranean area and, in particular, of the Cenozoic basins. The persistence of numerous interpretations and still-open problems resulted in the proliferation of very different models. The reconstructions presented are highly influenced by difficulties often encountered in considering constraints introduced by models built by means of completely different methodological approaches. For example, major difficulties can arise in integrating data from individual classical disciplines (i.e., geology, stratigraphy, geophysics, tectonics, magmatology and plate kinematics) with those resulting from the use of modern technologies (i.e., digital processing, uses of software, field observations using drones, etc.) and generally aimed to support specific topics. These considerations lead researchers to believe that a multidisciplinary approach would always be auspicious for these studies, because a greater control of the reconstruction of geologic and geodynamic events, and, therefore, for resulting models, would be ensured. After some considerations about different types of literature models based on specific investigation methodologies, the updating of a recently presented evolutionary model is proposed by attempting to integrate as much data as possible about the Cenozoic basins of the central-western Mediterranean area.Research supported by: grants from the University of Urbino Carlo Bo (F. Guerrera and M. Tramontana); Research Project CGL2016-75679-P, Spanish Ministry of Education and Science; Research Groups, Projects of the Generalitat Valenciana, Alicante University (CTMA-IGA)

Tectono-Sedimentary Evolution of the Cenozoic Basins in the Eastern External Betic Zone (SE Spain)

Four main unconformities (1–4) were recognized in the sedimentary record of the Cenozoic basins of the eastern External Betic Zone (SE, Spain). They are located at different stratigraphic levels, as follows: (1) Cretaceous-Paleogene boundary, even if this unconformity was also recorded at the early Paleocene (Murcia sector) and early Eocene (Alicante sector), (2) Eocene-Oligocene boundary, quite synchronous, in the whole considered area, (3) early Burdigalian, quite synchronous (recognized in the Murcia sector) and (4) Middle Tortonian (recognized in Murcia and Alicante sectors). These unconformities correspond to stratigraphic gaps of different temporal extensions and with different controls (tectonic or eustatic), which allowed recognizing minor sedimentary cycles in the Paleocene–Miocene time span. The Cenozoic marine sedimentation started over the oldest unconformity (i.e., the principal one), above the Mesozoic marine deposits. Paleocene-Eocene sedimentation shows numerous tectofacies (such as: turbidites, slumps, olistostromes, mega-olistostromes and pillow-beds) interpreted as related to an early, blind and deep-seated tectonic activity, acting in the more internal subdomains of the External Betic Zone as a result of the geodynamic processes related to the evolution of the westernmost branch of the Tethys. The second unconformity resulted from an Oligocene to Aquitanian sedimentary evolution in the Murcia Sector from marine realms to continental environments. This last time interval is characterized as the previous one by a gentle tectonic activity. On the other hand, the Miocene sedimentation was totally controlled by the development of superficial thrusts and/or strike-slip faults zones, both related to the regional geodynamic evolutionary framework linked to the Mediterranean opening. These strike-slip faults zones created subsidence areas (pull-apart basin-type) and affected the sedimentation lying above the third unconformity. By contrast, the subsidence areas were bounded by structural highs affected by thrusts and folds. After the third unconformity, the Burdigalian-Serravallian sedimentation occurred mainly in shallow- to deep-water marine environments (Tap Fm). During the Late Miocene, after the fourth unconformity, the activation of the strike-slip faults zones caused a shallow marine environment sedimentation in the Murcia sector and a continental (lacustrine and fluvial) deposition in the Alicante sector represented the latter, resulting in alluvial fan deposits. Furthermore, the location of these fans changed over time according to the activation of faults responsible for the tectonic rising of Triassic salt deposits, which fed the fan themselves.Research supported by: Research Project CGL2016-75679-P, Spanish Ministry of Education and Science; Research Groups, Projects of the Generalitat Valenciana, Alicante University (CTMA-IGA); University of Urbino Carlo Bo (funds to M. Tramontana)

Geodynamic Implications of the Latest Chattian-Langhian Central-Western Peri-Mediterranean Volcano-Sedimentary Event: A Review

High amounts of Chattian-Langhian orogenic magmatism have generated volcaniclastic deposits that are interbedded within the penecontemporaneous sedimentary marine successions in several central-western peri-Mediterranean chains. These deposits are widespread in at least 41 units of different basins located in different geotectonic provinces: (1) the Africa-Adria continental margins (external units), (2) the basinal units resting on oceanic or thinned continental crust of the different branches of the western Tethys, (3) the European Margin (external units), and (4) the Western Sardinia zone (Sardinia Trough units). The emplacement of volcaniclastic material in marine basins was controlled by gravity flows (mainly turbidites; epiclastites) and fallout (pyroclastites). A third type comprises volcaniclastic grains mixed with marine deposits (mixed pyroclastic-epiclastic). Calc-alkaline magmatic activity is characterized by a medium- to high-potassium andesite-dacite-rhyolite suite and is linked to complex geodynamic processes that affected the central-western Mediterranean area in the ∼26 to 15 My range. The space/time distribution of volcaniclastites, together with a paleogeographic reconstructions, provide keys and constraints for a better reconstruction of some geodynamic events. Previous models of the central-western Mediterranean area were examined to compare their compatibility with main paleotectonic and paleogeographic constraints presented by the main results of the study. Despite the complexity of the topic, a preliminary evolutionary model based on the distribution of volcaniclastites and active volcanic systems is proposed.Research was supported by grants from the University of Urbino to F. Guerrera and M. Tramontana; by the CGL2016-75679-P research project (Spanish Ministry of Education and Science); and by research groups and projects of the Generalitat Valenciana from Alicante University

Karst landforms Within Noctis Labyrinthus, Mars

Noctis Labyrinthus is an intricate system of Late Hesperian and Early Amazonian linear troughs and rounded pits connecting the Tharsis volcanic rise and western Valles Marineris next to Martian equator. This study was focused on three light-toned deposits (LTDs) located within a trough located in the western part of Noctis Labyrinthus, centered at −6.8°N, 261.1°E, approximately 60 x 50 km in dimension and with a depth of 5 km below the adjacent plateau. These LTDs located on the floor in the central region of this trough display spectral signature of gypsum and are characterised by the widespread presence of shallow depression morphologies. We performed a morphologic and morphometric analysis of the surfaces of these LTDs through an integrated study of images available through the Reconnaissance Mars Orbiter High-Resolution Imaging Science Experiment with the aim to describe, for the first time, these landforms, and to discuss their possible origins and lithological and paleo-climatic significance. Analysis, on the basis of the characteristics of the investigated landforms and the similarities of features on Earth and Mars, and after discarding other possible origins, revealed that the examined Martian landforms have karst origin. The landform features appear to reflect water-related processes, probably due to ice melting formed during periods of ice-snow-rich deposition from the atmosphere as the result of changes in the obliquity of Mars, which could have driven the processes of dissolution or collapse on the evaporite rock. Thus, the observed karst landforms suggest a climate change and the presence of liquid water due to ice melting during the Late Amazonian age.Key words: karst, gypsum, shallow depressions, climate change, Noctis Labyrinthus, Mars

Volcaniclastites as a key for geodynamic constraints in the evolution of the central-western Mediterranean region: an overview

In the central-western peri-Mediterranean chains, a consistent latest Chattian-Langhian orogenic calc-alkaline magmatism generated a high amount of volcaniclastites interbedded within penecontemporaneous marine successions. Emplacement of volcaniclastites is due mainly to epiclastic processes, implying paleogeographic constraints that instead do not control the distribution of fall-out pyroclastic deposits. Current knowledge does not allow direct correlations to be established between specific volcanic events and related secondary products; thus, reconstructions are based on field and analytic data. The volcanic activity occurred: (i) in the Adria Plate (during continental collision between the Mesomediterranean Microplate and the Adria-Africa Plate); (ii) along active subduction margins with different volcanic arc systems ("Mesomediterranean Microplate" Margin); (iii) back-arc basins (Apennine-Maghrebian-Betic systems; southwestern Corsica Margin and Sardinia Trough) due to rollback of the subductional slab; (iv) rifting (SE European Margin; e.g. Valencia and Provençal Basins) and (v) basins related to a strike-slip fault zone (Subbetic Basin). In this context it bears noting the scarcity at present of potential source areas consisting of primary products, suggesting that explosive volcanic arcs were quickly effaced during subduction. Instead, in rifting zones in the back arc areas the volcanic activity continues also in successive times and is testified to by several primary volcanic products. Paleogeographic and depositional constraints indicate multiple volcanic sources (arcs) located in different contexts but always near sedimentary basins. The study helps elucidate the evolution of interconnected geodynamic events in an original paleogeographic-paleotectonic framework.All this research was supported by Urbino University grants to F. Guerrera and M. Tramontana; CGL2012-32169 and CGL2016-75679-P research project (Spanish Ministry of Education and Science), by Research Groups and projects of the Generalitat Valenciana from Alicante University (CTMA-IGA)

The Early Miocene “Bisciaro volcaniclastic event” (northern Apennines, Italy): a key study for the geodynamic evolution of the central-western Mediterranean

The Early Miocene Bisciaro Fm., a marly limestone succession cropping out widely in the Umbria–Romagna–Marche Apennines, is characterized by a high amount of volcaniclastic content, characterizing this unit as a peculiar event of the Adria Plate margin. Because of this volcaniclastic event, also recognizable in different sectors of the central-western Mediterranean chains, this formation is proposed as a “marker” for the geodynamic evolution of the area. In the Bisciaro Fm., the volcaniclastic supply starts with the “Raffaello” bed (Earliest Aquitanian) that marks the base of the formation and ends in the lower portion of the Schlier Fm. (Late Burdigalian–Langhian p.p.). Forty-one studied successions allowed the recognition of three main petrofacies: (1) Pyroclastic Deposits (volcanic materials more than 90 %) including the sub-petrofacies 1A, Vitroclastic/crystallo-vitroclastic tuffs; 1B, Bentonitic deposits; and 1C, Ocraceous and blackish layers; (2) Resedimented Syn-Eruptive Volcanogenic Deposits (volcanic material 30–90 %) including the sub-petrofacies 2A, High-density volcanogenic turbidites; 2B, Low-density volcanogenic turbidites; 2C, Crystal-rich volcanogenic deposits; and 2D, Glauconitic-rich volcaniclastites; (3) Mixing of Volcaniclastic Sediments with Marine Deposits (volcanic material 5–30 %, mixed with marine sediments: marls, calcareous marls, and marly limestones). Coeval volcaniclastic deposits recognizable in different tectonic units of the Apennines, Maghrebian, and Betic Chains show petrofacies and chemical–geochemical features related to a similar calc-alkaline magmatism. The characterization of this event led to the hypothesis of a co-genetic relationship between volcanic activity centres (primary volcanic systems) and depositional basins (depositional processes) in the Early Miocene palaeogeographic and palaeotectonic evolution of the central-western Mediterranean region. The results support the proposal of a geodynamic model of this area that considers previously proposed interpretations.This research was supported by Urbino University funds (responsibles F. Guerrera and M. Tramontana); by CGL2011-30153-CO2-02 and CGL2012-32169 Research Project (Spanish Ministry of Education and Science); and by Research Groups and projects of the Generalitat Valenciana and Alicante University (CTMA-IGA)

The Historic Centre of Urbino, UNESCO World Heritage (Marche Region, Italy): an Urban‑Geological Itinerary Across the Building and Ornamental Stones.

The local and extra-regional (national and transnational) stones mainly used as building and ornamental materials in the historic centre of Urbino (UNESCO World Heritage List) were unravelled through a detailed geological and petrographic study. The types of building stones used in the past for the development of an urban centre were mostly affected by the availability of suitable geomaterials in the surrounding areas. For this reason, the stones found in the historical buildings of Urbino generally come from the local sedimentary formations (mostly limestones) belonging to the Umbria–Marche–Romagna Succession Auct., which crops out in the Northern Marche Apennines. Only some ornamental highly prized stones used for monuments and decorations come from both extra-regional Italian areas (Alps, other sectors of the Northern Apennines) and foreign countries (France, Egypt). A brief description of the Northern Marche geology was also reported to exactly match the local provenance of the stones, so highlighting the relationship between the territory and the architecture of Urbino. Because of obvious conservation reasons, no samples were collected from buildings or monuments and only autoptic observations, together with a detailed historical and bibliographic research, were carried out to identify the different materials and the provenance areas. Besides the availability of the local sedimentary rocks, we emphasised how the choice of the building and ornamental stones could have been also influenced by the historic period and artistic style, aesthetic features, economic and social importance of the building and/or monument and the relationship to some distinguished personality (e.g., Pope Clemente XI). An open-air stone itinerary across significant places (10 stops and additional sites and monuments in the urban area) is finally proposed for the best fruition of the geological and cultural heritage of Urbino, also aimed at geotourism development

Cenozoic tectono-sedimentary evolution of the onshore-offshore Tunisian Tell: Implications for oil-gas research

A review of the paleogeographic and tectonic reconstruction of the onshore and offshore Tunisian margin during the Cenozoic is discussed. Five unconformities (A to E) and associated stratigraphic gaps of various vertical extents allow subdivision of the stratigraphic record into depositional units in the following time intervals: (i) Paleocene-Oligocene, (ii) Oligocene-early Aquitanian, (iii) early Aquitanian-Burdigalian, (iv) late Burdigalian-Langhian and (v) Langhian-late Miocene. These intervals can in turn be grouped into four main sedimentary cycles (SC1–SC4) dated to the (1) Paleocene-Oligocene, (2) Oligocene–Burdigalian, (3) Burdigalian-Langhian and (4) Langhian-late Miocene. The oldest depositional unit reflects Eo-Alpine tectonics in the Maghrebian Flysch Basin (MFB); the others are related to the Neo-Alpine syn- and late orogenic tectonic deformation affecting the MFB. The uppermost unit represents post-orogenic deposition. Early Miocene synsedimentary tectonism led to (1) deposition of thick successions owing to a large sediment supply and (2) the occurrence of various tectofacies (unconformities, slumps, mega-turbidites, olistostromes, growth folds, chaotic intervals and heterogenous lithofacies), that all, together with the occurrence of lateral change of facies, clearly indicate non-cyclical sedimentation. During the middle Miocene the Tunisian Tell underwent polyphase thrust tectonism, followed by late Miocene strike-slip deformation with contemporaneous rejuvenation of halokinetics and magmatism (the La Galite Archipelago) that may be traced as far as the Algerian Tell. The margin experienced deep-seated compressional tectonism during the Paleogene, a foreland basin during the early Miocene, and nappe stacking during the middle Miocene, with the occurrence of wedge-top sub-basins. The evolution of the region makes the existence of petroleum resources within either the thrust belt, the foredeep and/or the foreland systems plausible. Oil and/or gas may have been trapped in either i) deep buried allochthonous thrust wedges that are located below the Numidian Nappes, and/or in ii) the imbricate Medjerda Valley domain of the Tell foredeep. The offshore area between northern Tunisia and the La Galite Archipelago may also hold potential for large oil/gas fields, as has been confirmed by exploration of the same overthrust belt in other areas such as in Sicily and the Southern Apennines.Research supported by Research Project PID2020-114381 GB-I00, Spanish Ministry of Education and Science; Research Groups and Projects from M. Martín-Martín, Alicante University (CTMA-IGA)