Central Iranian playas: The first 3D near-surface model

Abstract

Playas are a valuable tool for studying the climate of the past. In recent years, several studies have been conducted on Iranian playas, but there is a lack for subsurface models of playas. The aim of this research was to model the subsurface of playa to reconstruct the past climate. We employed the drilling cores of wells drilled in the two large playas in central part of Iran and created 3D models from near-surface structures. We obtained 3 models: an eight-layer model and a 4- layer model and a 2-layer models in 3 different parts. Based on the models, we have proposed a scenario for the evolution of central Iran playas. The 3D models show that the overlaying of the layers not only follows the morphology of the bedrock, but also that the mud layers sit exactly in the wet basins. In other words, layers of mud have formed in wetter-than-present surfaces. The 8-layers model suggest at least four periods of severe climate change had occurred in central Iran. Our 3D models are consistent with the reality of the climate change during Quaternary time scale in arid environment of central Iran.