Late Cretaceous paleosols as paleoclimate proxies of high-latitude Southern Hemisphere: Mata Amarilla Formation, Patagonia, Argentina

VARELA, AUGUSTO N.; RAIGEMBORN, M. SOL; RICHIANO, SEBASTIÁN; WHITE, TIM; POIRÉ, DANIEL G.; LIZZOLI, SABRINA

SEDIMENTARY GEOLOGY

ELSEVIER SCIENCE BV

Año: 2018 vol. 363 p. 83 - 95

0037-0738

Although there is general consensus that a global greenhouse climate characterized the mid-Cretaceous, detailsof the climate state of the mid-Cretaceous Southern Hemisphere are less clearly understood. In particular, continentalpaleoclimate reconstructions are scarce and exclusively derived from paleontological records. Usingpaleosol-derived climofunction studies of the mid- to Upper Cretaceous Mata Amarilla Formation, southernPatagonia, Argentina, we present a reconstruction of the mid-Cretaceous climate of southern South America.Our results indicate that at ~60° south paleolatitude during the Cenomanian?Santonian stages, the climate wassubtropical temperate?warm(12 °C±2.1 °C) and humid (1404±108mm/yr)with marked rainfall seasonality.These results are consistent with both previous estimations fromthe fossil floras of theMata Amarilla Formationand other units of the Southern Hemisphere, and with the previous observations of the displacement of tropicaland subtropical floras towards the poles in both hemispheres. The data presented here show a more marked seasonalityand slightly lower mean annual precipitation and mean annual temperature values than those recordedat the same paleolatitudes in the Northern Hemisphere.