The Pliocene-Quaternary boundary, approx. 2.6 million years ago (2.6 Ma), represents a time of rapid global climate change from warm and moist to cool and arid (i.e., glacial) conditions. The influence of this climate change on both sedimentation and tectonics is preserved in strata within the Qaidam Basin, China. Overall, climate-controlled basin aridification initiated 3.1 million years ago and caused the gradual change from more humid lacustrine sedimentation to evaporite conditions by 2.6 Ma. After 2.6 Ma, uplift above active structures combined with wind erosion of the basin sediments produced localized sediment traps that controlled sedimentation. This study provides isotopic (O and C), paleomagnetic, and sedimentologic data that distinguish the climatic versus tectonic controls on sedimentation and erosion within the northeastern Tibetan Plateau at this important time period.
Variation of climate and long-term erosion rates across a steep rainfall gradient on the Hawaiian island of Kauai
Ken L. Ferrier et al., Dept. of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, USA. Posted online 22 Feb. 2013; http://dx.doi.org/10.1130/B30726.1.
The erosion of volcanic ocean islands creates dramatic landscapes, modulates Earth's carbon cycle, and delivers sediment to coasts and reefs. Despite concerns that modern sediment fluxes to island coasts may exceed long-term fluxes, little is known about how erosion rates and processes vary across island interiors. This study by Ken L. Ferrier and colleagues presents new measurements of erosion rates over five-year to five-million-year time scales on the Hawaiian island of Kauai, which is home to one of Earth's steepest precipitation grad
|Contact: Kea Giles|
Geological Society of America