The main fields of my research group are Igneous Petrology, Volcanology, and Isotope Geochemistry. I use isotopes, trace elements, and equations to investigate magma generation, transportation, and eruption processes. I further explore the relationship between magma generation and global geodynamic processes in order to ultimately understand how the Earth works. Because of the versatility of isotopes and equations, my research has naturally expanded to a broad spectrum of the geosciences, including paleoclimates and sediment provenances.
To solve geological problems, we measure U-series, Nd, Sr, Pb, Hf, and O isotopes in rocks and minerals using mass spectrometers, including thermal-ionization, secondary-ionization, and plasma-ionization mass spectrometers. These isotopes serve as geological clocks and tracers.
Our research investigations have been supported by US National Science Foundation (NSF) and National Science Foundation of China (NSFC), American Chemical Society Petroleum Research Fund (ACS-PRF), and National Aeronautics and Space Administration (NASA) Johnson Space Center. More specific research interests are given as follows.
(1) Active Volcanology
We study young volcanoes in China and the U.S. In an NSF-funded project, our work on Mount Changbai successfully dated very young (<10 thousand years) zircons with high accuracy and precision, and provides evidence for short magma storage times for the magmas. My NSF of China funded studies on Tengchong volcanoes represent the first successful application of shallow depth profiling dating of unpolished zircon surfaces using 238U-230Th disequilibrium isochrons. Magma and zircon 238U-230Th isotope disequilibrium, in spite of the analytical difficulty to measure 230Th isotope, is one of the primary strengths of my research group. Recently, we began extending our volcano research to pre-eruptive volatile compositions and contents preserved in magma inclusions in crystals.
(2) Magma Generation and Geodynamics.
Temporal and spatial distributions of diverse magmatic rocks and their variations of chemical and isotopic composition reflect deep geodynamic processes within the Earth. My work on mid-ocean ridge basalts from East Pacific Rise to constrain lateral magma transport was published in Science. Work on Cenozoic continental basaltic magmas from SE China has revealed two deep mantle domains beneath East Asia. A related paper in Chemical Geology has been cited more than 300 times. Isotope dating of ophiolites (ancient oceanic crust) from SE China demonstrated that Earth’s modern-style plate tectonics began at least 900 million years ago. U-series isotopes in basalts from NE China provide new insights into the stagnant subducted Pacific slab 400 km below East Asia. Isotope studies of igneous rocks from the Tarim basin provided constraints on the tectonic framework and evolution of the Tarim Block. A related paper in Gondwana Research is a top 1% highly cited paper in the geosciences according to ISI Web of Science.
(3) Geochemical Modeling
To quantify physical, chemical, geological, and biological processes is always an important goal in natural sciences. Quantitative modeling is another strength of my research group. Using differential equations and partition coefficients, I have developed quantitative geochemical models to describe the behavior of trace elements and uranium-series disequilibrium during mantle melting. These equations have been widely used by petrologists and geochemists for their research. Expanding from theoretical studies of partial melting to mass spectrometry, measurement calibration, error propagations, and data reduction, I wrote a highly-regarded single-authored book “Quantitative Geochemistry”. This book has been adopted in top geochemistry programs in the U.S. and abroad for their graduate course.
(4) Paleoclimates
Based on isotopic compositions of Fe-Al-rich inclusions in basalts, we propose that these unusual inclusions represent aluminous lateritic palaeosols formed at extraordinary hot and humid tropical greenhouse conditions 15-17 million years ago (Ma). These inclusions in basalts thus have preserved the evidence of global warming at 17-15 Ma that would otherwise have been lost by erosion of the palaeosols. In another project, based on U-Pb dating of zircons from the volcanic layers interbedded with glacial deposits within the Tarim basin, we provide constraints on the extent and timing of the Neoproterozoic Snowball Earth, a global cooling period during 740 to 550 Ma.
(5) Sandstone Provenance
In a newly funded ACS-PRF project, Zou and Dr. David King will investigate the provenance of Cretaceous sandstones of the Arkansas coastal plain. Petrology of these sandstones will establish their composition in the outcrop area, which will be useful as a comparison to down-dip subsurface reaches of the Arkansas, Louisiana, and Texas coastal plain where some of the sands in these units are hydrocarbon-bearing. By measuring the age distributions of detrital zircons from the Cretaceous sandstones, we will test a hypothesis that these Cretaceous sandstones from Arkansas were mostly derived from the Ouachita Mountains. This fundamental research on the outcrop Cretaceous sandstones is strongly related to petroleum exploration in Arkansas and adjacent areas of the Gulf basin.
I am a geologist with a high-level of expertise in mass spectrometry, applied mathematics, and trace metal clean lab chemistry. My approach to research is to combine accurate measurements by mass spectrometry with solid mathematical modeling. I pay special attention to quantitative models, innovative experimental methods, and bold/creative (sometimes a bit crazy) interpretations. A combined experimental and theoretical study can solve scientific problems more thoroughly and elegantly.