Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

• Load cast In the lower and middle sections of the outcrop load casts were observed. These structures have a semi-spherical shape with concave-upward geometry and vertical widening, featuring internal lamination that follows the structure's contours. Load casts are predominantly observed at points where upper stratigraphy penetrates lower layers, particularly between unit U5 and U4, as well as between U7 and U6 (Fig. 2d). They vary in size, with diameters ranging from 12 to 15 cm and heights from 10 to 30 cm, some acting independently and penetrating up to 20 cm into the sedimentary cover. • Flame structures In the middle part of the outcrop, flame structures have been identified, displaying a cusp- or wedge-shaped morphology that points upwards (Fig. 2d). These structures are consistently associated with load cast structures, albeit on a smaller scale. Comprising mudstone from stratigraphic unit 4 and intruding into claystone from stratigraphic unit 5, flame structures are also observed between the base of stratigraphic unit 7 and the top of stratigraphic unit 6. They vary in size, ranging from 3 cm in length to 4 cm in height. • Deformed lamination In the middle part of the outcrop, deformed laminations characterized by layers of folded, broken and wrinkled claystone have been identified. These structures extend throughout stratigraphic unit 5. These structures are surrounded by claystone at the top and bottom that are not deformed and are found in a localized part of the unit (Fig. 2e). The maximum thickness of these deformed beds is approximately 20 cm. • Pseudonodules Deformation structures resembling pseudonodules have been identified in the lower section of the outcrop. These structures appear as isolated sediment masses with diverse shapes, including conical, cigar-shaped, semicircular, and elliptical. Comprising claystone from the overlying stratigraphic unit 1, the cores of these structures are entirely detached from the surrounding sediment, precisely encapsulated at the base of stratigraphic unit 2. The pseudonodules vary in size from 5 to 10 cm and can extend up to 25 cm into the underlying bed (Fig. 2f). • Discussion / Deformation mechanics The deformation structures observed in the outcrop are interpreted to be the result of fluidization and liquefaction processes in non- lithified, water-saturated sedimentary layers, supporting previous research (Shanmugam, 2017). The formationof ball-and-pillow, load cast, flame-like structures and pseudonodules is attributed to gravity instabilities, where denser upper layers collapse and penetrate into less denseunderlying layers.Deformed lamination inpeliticdeposits is not linked to lithologic contrasts, suggesting deformation by liquefaction and shear stresses (Moretti & Sabato, 2007). Loop bedding is interpreted as deformations by stretching of unconsolidated pelitic sediments, evidencing contrasts in competence (Calvo et al., 1998).