Browsing by Author "Pinto, L."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Association of inflammatory and other immune markers with gallbladder cancer : Results from two independent case-control studies
    (2016) Pinto, L.; Koshiol, J.; Castro, F.; Kemp, T.; Gao, Y.; Roa Strauch, Juan Carlos Enrique; Wang, B.; Nogueira, L.; Araya, J.; Ferreccio Readi, Catterina; Rashid, A.; Hsing, A.; Hildesheim, A.; Shen, M.; Pfeiffer, R.
  • No Thumbnail Available
    Item
    Plio–Pleistocene stratigraphy of the Horcón Basin (central Chile, ∼33°S): Transgressive–regressive cycles and forearc deformation above the Juan Fernández Ridge
    (Elsevier B.V., 2025) Pinto, L.; San Juan M.; Villasenor T.; Rodriguez M.P.; Flores-Aqueveque V.; Naipauer M.; Le Roux J.P.; Cuevas R.
    © 2025 Elsevier B.V.This paper analyzes the marine and continental successions of the Neogene to Quaternary Horcón Basin (32°–33°S), a forearc basin of the Central Andes, based on sedimentological, stratigraphic, and U[sbnd]Pb detrital zircon geochronological data. The basin lies above the present-day projection of the Juan Fernández Ridge (JFR), which has been subducting beneath the South American Plate at a fixed piercing point over the past ∼10 million years. An initial transgressive episode (Late Pliocene) is recorded in successions that grade from middle transitional to deeper offshore settings. A prominent erosional surface overlying these deposits marks a subsequent regressive phase. This was followed by a second transgression (Early Pleistocene?), preserved in a deepening-upward sequence dominated by gravelly upper shoreface to foreshore facies. A later regression (Early to Middle Pleistocene?) is expressed by debris flow deposits and extensive alluvial braidplains progradationally advancing toward the coast. Detrital zircon U[sbnd]Pb ages and gravel composition indicate sediment sources from Jurassic and Cretaceous arc rocks of the Coastal Cordillera throughout the basin's evolution, with a significant contribution from the Principal Cordillera possibly linked to tectonic activity upstream of the Aconcagua River. We suggest that the first transgressive episode may reflect regional subsidence, whereas the subsequent regression could be associated with regional uplift of the South American margin at these latitudes. Additionally, the transgressive–regressive cycles documented in the Horcón Basin likely record localized vertical motions driven by coastal normal faulting, resulting in high-relief coastal blocks and embayments. While further evidence is needed, we propose that this complex deformation history, occurring within an overall compressive regime, may have been modulated by the subduction of JFR seamounts, contributing to localized subsidence and uplift along the margin of the overriding plate.
  • No Thumbnail Available
    Item
    The effects of differential shortening and competent blocks on the structural development of Andean fold-and-thrust belts at 32°-34°S: Insights from analogue models
    (2023) Jara, P.; Herrera, S.; Villarroel, M.; Pinto, L.; Yagupsky, D.; Guzman, C.; Gutiwrrez, M.
    Andean fold-and-thrust belts (FTBs) in the western border of South America show important along-strike variations in their structural style (thin- or thick-skinned) and shortening magnitudes, among others. These variations can arise from multiple factors, such as depth-to-detachment, geometry, and thickness of underlying basins, structural highs, the competence of the units involved in deformation, pre-orogenic structure of the basement, the rheological state of the upper crust or latitudinal gradients in shortening, among others. We carry out a set of new analogue models to understand how two of these factors affect the development and the geometry of the thrust systems within the Andean Principal Cordillera and adjacent fold-and-thrust belts at 32 & DEG;-34 & DEG;S (La Ramada and Aconcagua FTBs). In this contribution, we present the results of analogue modeling of doubly-vergent thrust systems with a built-in heterogeneity that allow us to evaluate the influence of differential shortening and presence of competent blocks (of relatively higher cohesion) in the generation, evolution, and structural setting of Andean FTBs. We highlight that despite the similar pattern of differential shortening in the models, the presence of the competent block has a significant influence on the structural configuration and leads to greater topographic uplift. Differential shortening plays a role in accommodating deformation, but when a competent block is present, the faults bounding the block control the deformation, producing a notable curvature of the FTBs. Summarizing, the presence of a competent block significantly influences the structural configuration within a doubly-vergent thrust system, emphasizing the role of inherited architecture in the orogenic growth of the Southern Central Andes.