On the devil's tracks: unexpected news from the Foresta ichnosite (Roccamonfina volcano,central Italy)

The Foresta ichnosite is well known for preserving some of the oldest human fossil footprints recorded in Europe so far. This research aims to: i) describe new footprints that are larger than those already reported, some of which form a new trackway that moves in the opposite direction to all the others; ii) announce the discovery of some stone tools also in the surroundings of the Foresta ichnosite. The new results increase the total number of human fossil footprints to at least 81, specify the direction and the number of footprints of Trackway C, and identify three new directions of walking at the site. More compelling and complete estimates of the dimensional range of all ichnological evidence enables us, furthermore, to estimate the number of trackmakers walking on the trampled surface as a minimum of five, one of them likely being an adult male. The general shape of all the recorded footprints suggests that the Foresta trackmakers share some similarities with those at Sima de los Huesos, and belong to the same taxonomical group as the Ceprano skull. All the new evidence enables us to better understand the presence of hominin populations in the Roccamonfina volcano area during the Middle Pleistocene. © 2020 John Wiley & Sons, Ltd.     

New insights on pressure,temperature, and chemical stability of CsAlSi<Subscript>5</Subscript>O<Subscript>12</Subscript>, a potential host for nuclear waste

A Cs-bearing polyphase aggregate with composition (in wt%): 76(1)_CsAlSi5O12 + 7(1)_CsAlSi2O6 + 17(1)_amorphous, was obtained from a clinoptilolite-rich epiclastic rock after a beneficiation process of the starting material (aimed to increase the fraction of zeolite to 90 wt%), cation exchange and then thermal treatment. CsAlSi₅O₁₂ is an open-framework compound with CAS topology; CsAlSi₂O₆ is a pollucite-like material with ANA topology. The thermal stability of this polyphase material was investigated by in situ high-T X-ray powder diffraction, the combined P–T effects by a series of runs with a single-stage piston cylinder apparatus, and its chemical stability following the “availability test” (“AVA test”) protocol. A series of additional investigations were performed by WDS–electron microprobe analysis in order to describe the P–T-induced modification of the material texture, and to chemically characterize the starting material and the run products. The “AVA tests” of the polyphase aggregate show an extremely modest release of Cs⁺: 0.05 mg/g. In response to applied temperature and at room P, CsAlSi₅O₁₂ experiences an unquenchable and displacive Ama2-to-Amam phase transition at about 770 K, and the Amam polymorph is stable in its crystalline form up to 1600 K; a crystalline-to-amorphous phase transition occurs between 1600 and 1650 K. In response to the applied P = 0.5 GPa, the crystalline-to-amorphous transition of CsAlSi₅O₁₂ occurs between 1670 and 1770 K. This leads to a positive Clapeyron slope (i.e., dP/dT > 0) of the crystalline-to-amorphous transition. When the polyphase aggregate is subjected at P = 0.5 GPa and T > 1770 K, CsAlSi₅O₁₂ melts and only CsAlSi₂O₆ (pollucite-like; dominant) and Cs-rich glass (subordinate) are observed in the quenched sample. Based on its thermo-elastic behavior, P–T phase stability fields, and Cs⁺ retention capacity, CsAlSi₅O₁₂ is a possible candidate for use in the immobilization of radioactive isotopes of Cs, or as potential solid hosts for ¹³⁷Cs γ-radiation source in sterilization applications. More in general, even the CsAlSi₅O₁₂-rich aggregate obtained by a clinoptilolite-rich epiclastic rock appears to be suitable for this type of utilizations.     

Experimental assessment of the seismic performance of hospital cabinets using shake table testing

An experimental investigation of hospital building equipment is presented. Dynamic properties and seismic performance of typical ambulatory freestanding cabinets are assessed by unidirectional and bidirectional shake table tests, also considering the presence of internal partitions and cabinet contents. Vulnerability analysis is performed according to the most recent and reliable assessment methods, evaluating the influence of different parameters of the sample cabinets. The performance criteria referred within this research are the limit states reached by the specimens (ie, rocking and overturning) and by their contents (ie, overturning and breaking). Fragility curves are evaluated for the components and the contents, considering both acceleration and velocity intensity measures, and also using dimensionless intensity measures developed in recent studies. The outcomes of the present study confirm the findings of previous laboratory tests and numerical simulations carried out by the same authors and provide a further insight for the reliable seismic performance assessment of hospital cabinets and their contents.     

Controls on large boulder mobility in an ‘auto-naturalized’ constructed step-pool river: San Clemente Reroute and Dam Removal Project,Carmel River,California, USA

A 1200 m-long river segment of Carmel River (California) was constructed to bypass trapped reservoir sediment when San Clemente Dam was removed from the Carmel River in 2015. Hundreds of large boulders were used to construct 53 steps in an 800 m-long reach of the project. Nearly all the boulders were scattered to new locations in high flows of 2017, and have been relatively stable since that time. We analysed the causes of incipient motion and distance travelled for 226 randomly selected large boulders (0.5–1.8 m) impacted by a flood event in winter of 2019. Channel width, water depth, and isolation from neighbouring boulders were the main variables controlling individual large boulder incipient motion during a 10-year peak flow event in the ‘auto-naturalized’ constructed step-pool river in 2019. There is weak statistical evidence that a combination of shear stress and the presence of boulders located laterally downstream of the subject boulder controlled the distance the boulder moved. Frequentist statistics and Akaike information criterion model comparison determined that boulder size, boulder shape, boulder roundness, and local thalweg slope were not good predictors of large boulder incipient motion or distance transported. Average dimensionless critical shear value for the four largest mobilized boulders (1.5–1.6 m) was 0.014. We describe the geomorphic history of the site and use our results to discuss potential causes of unanticipated large boulder transport at the site that occurred in a <2-year peak flow of winter 2016 soon after step construction. © 2020 John Wiley & Sons, Ltd.     

Confronto fra i regimi pluviometrici di Genova e Savona

Riassunto L'esame dei giorni di ciascun anno dal 1886 al 1900 nei quali si sono avute precipitazioni apprezzabili tanto a Genova quanto a Savona (località distanti fra loro 35 km) viene istituito utilizzando l'indice di similitudineS recentemene introdotto daM. Bouët. La discussione dei risultati dimostra fra l'altro come le località marittime a ridosso di catene montuose siano più adatte a mettere in luce le variazioni nel tempo delle caratteristiche climatiche.

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Zusammenfassung Ausgehend von der Anzahl der gleichzeitigen Niederschlagstagen in Genua und Savona (Abstand 35 km) wurde der AehnlichkeitsindexS nachBouët für jedes Jahr der Periode 1886–1900 berechnet. Die Diskussion der Ergebnisse zeigt u.a., dass die maritimen Orte, die am Fusse einer Bergkette liegen, gewöhnlich besser als die kontinentalen geeignet sind die zeitlichen Veränderungen der klimatischen Verhältnisse darzustellen.

     

Seismic performance evaluation of plasterboard partitions via shake table tests

The damage of nonstructural components represents the largest contribution to the economic loss caused by an earthquake. Since nonstructural components are not amenable to traditional structural analysis, full-scale experimental testing is crucial to understand their behaviour under earthquake. For this reason, shaking table tests are performed to investigate the seismic behaviour of plasterboard partitions. A steel test frame is properly designed in order to simulate the seismic effects at a generic building storey. The tests are performed shaking the table simultaneously in both horizontal directions. To investigate a wide range of interstorey drift demand and seismic damage, the shakes are performed scaling the accelerograms at eleven different intensity levels. The tested plasterboard partitions from Siniat exhibit a good seismic behaviour, both in their own plane and out of plane, showing limited damage up to 1.1 % interstorey drift ratio. The correlation between the dynamic characteristics of the test setup and the recorded damage is evidenced. Finally, an interesting comparison between the experimental results and the analytical model is also performed.     

Post-eruptive processes in the Campanian Ignimbrite

Summary ¶This paper deals with the mineralogical features of the most important and widespread pyroclastic formation of Southern Italy: the Campanian Ignimbrite. This formation is characterized by four stratigraphic units, different in colour and mineralogical composition. The lowermost unit (USAF) is constituted by an incoherent, thin (few tens of cm) sequence of glass or feldspar-rich layers. The middle part of the succession is formed by two main units: a lower grey, welded unit (WGI) capped by a yellow and lithified unit (LYT) that differ in both volcanological features and mineralogical composition. Locally these units are found separately. An incoherent unit (max thickness about 2m) mainly represented by fresh glass, forms the upper part of the succession. A detailed analysis has been carried out on six sections representative of the entire succession. The WGI is feldspathized by authigenic mineralization processes, and the feldspar content ranges between 30 and 90%. The LYT has been deeply affected by zeolitization processes and the total zeolite content often reaches 60%. Based on a comparative examination of both volcanological and mineralogical data, it is hypothesized that these two units were involved in different secondary mineralization processes. The portion of the succession characterized by the highest emplacement temperatures suffered welding and feldspathization and the result of these processes gave rise to the WGI unit. In contrast, the overlying lower-temperature and incoherent portion of the deposit was affected by circulation of meteoric water, thus enhancing zeolitization and lithification. The product of this process gave rise to the LYT unit.Received July 4, 2002; revised version accepted April 23, 2003