IRES: Assessing Dust Landscapes Across Time

This International Research Experiences for Students award will train U.S. undergraduates to study the texture and mineralogy of mineral dust, a critical component of the most fertile agricultural soils on Earth. mineral dust, which is carried by winds and trapped in soils, contains nutrients important for photosynthesis, and contributes to formation of a loamy texture. In some regions, mineral dust accumulates at such great rates that it forms relatively thick deposits called ‘loess.’ Loess deposits, in turn, record information about past climates and climate change.

This mineral dust, which is mainly silt, is commonly created by glacial erosion (pulverization) of rocks, and in desert conditions, for example by collisions of sand grains in windstorms, or deflation of dry lake beds. Thus, understanding the origin of the dust is important for understanding past climates and modern soils. The goal of this project is to test the hypothesis that dust formed by glacial and desert processes can be distinguished using the texture and chemistry of the dust deposits.

The study area for the project is the Balkans, where famous loess deposits derived from glacial processes in northern Europe occur within ancient agricultural regions of Serbia, and where dust mantles derived from desert and other regions occur on limestone formations along the coast of Croatia. A cohort of six undergraduates per each of the three years of the projects will join the research.

Student selection is by competitive application, but with a focus on students from underserved and from rural regions of the US Midwest. In addition to receiving scientific mentoring from US, Serbian, and Croatian scientists, these students develop a strong sense of place, and an appreciation of the deep interconnectedness manifested in the nexus of geology, climate, agriculture and society.

Dust and loess deposits host soils of superior quality, and thus form the backdrop for much of the world’s agriculture — including in the breadbaskets of the U.S. and southeastern Europe. The focus of this student-driven research is to characterize dust deposits that have accumulated in the Balkans in Quaternary and Permian times. We hypothesize that these dust deposits record varying influences of dust derived primarily from periglacial sources and processes (Quaternary loess in Serbia—year 1), and dusts derived primarily from peridesert sources and processes (Quaternary terra rossa mantles in Croatia—year 2).

We wish to use empirical methods to ground-truth and contrast textural and compositional aspects of these hypothesized ‘end-member’ types of dust deposits. Then, we will use results to examine a Permian-aged, inferred dust deposit in Serbia (year 3), to assess its possible origin and paleoclimatic significance. In addition to field descriptions and sampling, the students measure parameters such as magnetic susceptibility, particle size and shape, mineralogy, and geochemistry, and conduct limited detrital-zircon (provenance) analyses.

Part of our study design, therefore, is to recruit U.S. students from rural areas, prioritizing those who are first-generation college students or from other underserved groups. The role of dust additions to creating fertile soils speaks to the importance of dust in aspects of agriculture, history, and economics. These are auxiliary themes that are raised during the mentorship program, and woven into the student research, and re-emphasized by our Serbian and Croatian collaborators.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.