Similar Magnetic Enhancement Mechanisms Between Chinese Loess and Alluvial Sediments From the Teruel Basin, NE Spain, and Paleoclimate Implications

Abstract

The Pliocene is considered an analog for future climate. Insolation is found the dominant forcing for Asian precipitation over the late Pliocene, evidenced by magnetic enhancement of Chinese loess caused by formation of nanometer-scale ferrimagnetic grains during pedogenesis corresponding to high precipitation. However, lack of European loess limits understanding of Pliocene European climate. We identified likely similar magnetic enhancement mechanism between Pliocene alluvial sediments from Spain and Chinese loess despite different depositional settings. This provides an opportunity to improve understanding of Pliocene climate in Europe. Spectral analysis shows that European wet-dry variations during the early Pliocene were forced by insolation and during the late Pliocene by both insolation and ice sheets development. During the Quaternary, in contrast, the forcing was dominantly from high latitude. These results demonstrate the importance of insolation during warm climates and the growing importance of ice sheets with global cooling in controlling Northern Hemisphere precipitation changes.