The Neogene and Quaternary deposits of the Barcelona city through the high-speed train line

Abstract

A total of 208 boreholes with continuous core sampling, drilled for the construction of the high-speed train line through the city of Barcelona and other nearby infrastructures, were studied. The correlation of the lithologic logs of these boreholes allows identifying five main depositional sequences bounded by sharp erosional surfaces: i) lower Miocene, of alluvial origin; ii) middle Miocene, of deltaic-lacustrine origin; iii) lower Pliocene, of beach-shelf origin; iv) Pleistocene, of alluvial origin and v) Holocene, of deltaic origin. The erosive surfaces that separate these sequences represent important erosive hiatus linked to prolonged sea level falls at regional scale, which eliminated the upper part of each one. Sedimentation took place during decreasing intensity of extensional tectonic activity that mainly affected the Miocene deposits. The Plio-Quaternary units show their original structure apparently without tectonic alterations. Some new biostratigraphic data based on foraminifer assemblages allowed making accurate estimate of the age of the deposits.

A K-Nearest Neighbors Algorithm in Python for Visualizing the 3D Stratigraphic Architecture of the Llobregat River Delta in NE Spain

“…The created interactive 3D HTML model for visualizing the 3D stratigraphic architecture (coarse lithosomes and the basement top surface) of the LRD is included in Supplementary Materials (3D_Lithosomes_ LRD.html (accessed on 12 July 2022)). In general, the results reproduce well the complex sedimentary structure of the LRD reported in recent scientific publications [20,[37][38][39]55,56], thus proving the suitability of the open-source KNN algorithm and Python libraries for visualizing the 3D stratigraphic structure of sedimentary basins. Other proves of the 3D model reliability are as follows.…”

“…When the sub-square raised and sunken sectors structure of the basement is compared with the geological sketch map from Figure 1, a clear correlation between the horst-graben boundaries and the main Tibidabo, Llobregat, and Morrot fault families and their associated minor-order faults is observed. These results reproduce well the complex sedimentary structure of the onshore LRD reported in recent scientific publications [20,[37][38][39]55,56].…”