Xu Homepage | The Department of Geoscience | The University of Wisconsin-Madison

Huifang Xu - Research Activities


Current Research in Mineral Science


 

Fig. 4Left: Hematite enhances aragonite nucleation: TEM image showing an aragonite crystal (A) nucleates on hematite (H) surface.

♦ Effect of non-carbonate minerals on nucleation and growth of carbonate minerals: Carbonate minerals and their crystallization processes have been an important subject of earth sciences for the past quarter centuries because of the minerals’ wide occurrence and high reactivity. The objective of this project is to examine the interfacial effect (both surface chemistry and structure) of common rock-forming oxide and silicate minerals on carbonate polymorphic composition during carbonate mineralization in model solution and simulated groundwater. This project is supported by Office of Basic Energy Science, U. S. Department of Energy.


 

fig. 5Left: Platy magnetite (left) and zincite (right) formed in organic-bearing solutions (Nature Materials, 2003)

♦ Minerals as biosignatures: The minerals formed through bioorganic- and enzyme-involved systems will display unique shape, chemistry, and architecture. Features such as these in Fe-sulfides, Fe-oxides, and carbonates / dolomite minerals may be used as potential biosignatures preserved in early earth sediments and Martian rocks. We also investigate the roles of lithotrophic bacteria on mineral transformations in Fe-oxides, Fe-hydroxides, and carbonate minerals in surface and subsurface environments. This is project is supported by NASA Astrobiology Institute.

 


 

Fig. 6Left: An Achaean BIF nearby Underground Mine State Park, Soudan, Minnesota

♦ BIF minerals and their formation environments: The research focuses on micro- and nano-phase minerals and their textures preserved in banded iron formation (BIF) to understand their formation conditions and mechanisms of formation. By combining mineralogical study and geochemical modeling, we try to understand mechanism for genesis of BIFs, and to constrain the Earth environment during the BIF formation period. BIF formation requires Fe-Si-rich geological fluids. Such fluids can be generated by hydrothermal alteration of komatiites, the low-Al oceanic rocks generated by deep mantle plumes on early earth. This research is supported by NASA Astrobiology Institute.

 

 

 

 


 

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