Hypogene speleogenesis and paragenesis in the Dolomites

The Dolomites of northern Italy feature some the most intensively studied carbonate rocks worldwide. Yet, little is known about long karst history this mountain range dating back to Miocene. This study scrutinizes three caves (F10, Milchloch and Cioccherloch) in Fanes-Sennes-Prags Nature Park (Province South Tyrol) adjacent Fosses area Natural Ampezzo Belluno, Veneto). Paleo-phreatic passages these limestone mostly follow a NW-SE orientation, similar nearby Val Salata fault. A multi-method approach including cave morphological isotopic analyses wall-rock cores was applied reconstruct multi-stage speleogenetic cavities. Clastic sediments partly cemented walls paragenetic features such as ceiling channels solutional ramps are present all caves. F10 shows widespread laughöhle geometries, inverted cone chambers horizontal with trapezoid cross sections, characteristic slow water convection hypogene regime. Drill exhibit systematic depletion both oxygen carbon isotopes close wall. thickness isotopically altered zone ranges from few mm 4 cm alteration can sometimes also be macroscopically identified. amplitude shift 2.0 5.0‰ for ?13C 1.9 4.9‰ ?18O. One wall rock Cioccherloch thin halo, while no evidence found Milchloch. Our results provide strong geochemical driven by water-rock interaction at least two We propose an early phase, followed uplift denudation resulting opening cavities surface that allowed clastic sediment influx. infill combination abundant records second phase evolution. did not involve waters, indicated lack features. latest speleogenesis represented vadose morphologies speleothems locally 650 ka. demonstrates fingerprinting represents powerful decipher commonly complex