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Neotectonics of the northern Mojave Desert

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Diagram showing the impact of sediment texture and water infiltration factors

Understanding surficial materials: Fundamental field science observations are critical to understanding geology-ecology interactions and relationships. For example, This diagram illustrates the types of surface soil characteristics on mapable (observable on the ground in large areas) geologic units. In this case, unit Qya3 represents relatively young alluvial fan surfaces (not active stream channels), and unit Qia3 is characteristic of older, typically elevated stream terraces deposits that have not been subjected to stream channel modification for many thousands of years. Older surfaces in the desert environment typically have pebble-covered surfaces (pavement) overlying a frothy mineral-rich undersoil (Av horizon). The interplay of weathering factors (precipitation, climate, biology, sediment type, etc.) over time produce these desert soil characteristics. These properties, in turn, affect how moisture infiltrates the ground, and how plants can utilize both the water and mineral nutrients available. Because these Qya and Qia surfaces are visible and mapable on a regional scale, they can be combined with satellite imagery, biological mapping, and other data to evaluate resources and model ecosystem characteristics, and possibly help predict the impacts of climate change.
graphic provided by David Miller

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