No abstract

No abstract

Through time, the wide area between southeastern Tuscany, northeastern Latium, and western Umbria has been revealed as a crucial area for understanding the evolution of Neogene basins in northern Apennine. In this study, the results of twenty years of research on the marine early Pleistocene deposits are summarized, and the biological and physical events are presented and discussed in order to propose an integrated stratigraphic scheme. The proposed reconstruction is also included in a wider context, taking into account both the local and regional geological evolution.

No abstract

Ambergrisichnus alleronae igen. et isp. nov. from early Pleistocene clay marine deposits of Umbria, central Italy is here described, and attributed to cololites (evisceralites) of sperm whales. This interpretation is supported by the following characteristics that are frequently identified in modern ambergris including: internal organization of concentric structures, external shape with converging striae and bulges (rognons), and inclusions of squid beaks. These cololites were deposited in a relatively deep (100-150 m) marine environment, and the large number of structures in a restricted area is plausibly ascribed to multiple death events of sperm whales. The description of A. alleronae igen. et isp. nov. is held by analysis of the taphonomic processes that took place after the sperm whale carcasses reached the seabed and led to fossilization. The analysis of benthic micro-and macrofauna found close to the studied structures provides supplementary data, which support the reconstruction of palaeoecological and palaeoenvironmental conditions comparable with those of the whale fall communities. This work increases knowledge of vertebrate coprolites. Moreover, this new information provides the data about the frequency of sperm whales in the Tyrrhenian Sea during the early Pleistocene, and raises new questions about the causes of this anomalous accumulation.

No abstract

Characterization, correlation and provenance determination of tephra samples in sedimentary sections (tephrochronological studies) are powerful tools for establishing ages of depositional events, volcanic eruptions, and tephra dispersion. Despite the large literature and the advancements in this research field, the univocal attribution of tephra deposits to specific volcanic sources remains too often elusive. In this contribution, we test the application of a machine learning technique named Support Vector Machine to attempt shedding new light upon tephra deposits related to one of the most complex and debated volcanic regions on Earth: the Pliocene-Pleistocene magmatism in Italy. The machine learning algorithm was trained using one of the most comprehensive global petrological databases (GEOROC); 17 chemical elements including major (SiO O 5 ) and selected trace (Sr, Ba, Rb, Zr, Nb, La, Ce) elements were chosen as input parameters. We first show the ability of support vector machines in discriminating among different Pliocene-Pleistocene volcanic provinces in Italy and then apply the same methodology to determine the volcanic source of tephra samples occurring in the Caio outcrop, an Early Pleistocene sedimentary section located in Central Italy. Our results show that: 1) support vector machines can successfully resolve high-dimensional tephrochronological problems overcoming the intrinsic limitation of two-and three-dimensional discrimination diagrams; 2) support vector machines can discriminate among different volcanic provinces in complex magmatic regions; 3) in the specific case study, support vector machines indicate that the most probable source for the investigated tephra samples is the so-called Roman Magmatic Province. These results have strong geochronological and geodynamical implications suggesting new age constraints (1.4 Ma instead of 0.8 Ma) for the starting of the volcanic activity in the Roman Magmatic Province.

No abstract