Rocking Mantle Group, NJU
The Rocking Mantle Group in Nanjing University and in Northwest University (Xi'an) is mainly engaged in the research of Igneous Petrology and Mantle Geochemistry.
Based on the field investigation, petrographic observation and geochemical study utilizing integrated tracer of elements, radiogenic isotopes (e.g.,Sr, Nd, Pb, Hf), and non-traditional stable isotopes (e.g. Mg, Fe, Zn and Ca) of mantle-derived volcanic rocks , we are aiming to study: (1) the chemical composition and evolution of mantle, especially the deep mantle, (2) the melting process occurred in the different part of the mantle, and (3) the evolution of magma or melts at different depth.
For the past years, our research primarily focused on the Intraplate Magmatism, including Cenozoic basalt in eastern China and oceanic island basalt (OIB) on the Pacific Plate.
1, Cenozoic basalts in northeastern China
The Cenozoic basalts in eastern China are mostly located in the northeast of China (Fig. 1). Recently, we have transferred our study area from northern and southern China to northeastern China. The type of Cenozoic magmatism in northeastern China is various, which varies from monogenetic volcanoes (mainly alkaline basalts) to small-scale flood basalts (mainly tholeiites) and from sodic to potassic, even ultra-potassic in chemical compositions. These rocks provide a window to understand the composition of the mantle, and their genetic link to the so-called 'Big Mantle Wedge'.
Figure 1. The distribution diagram of the Cenozoic basalts in northeastern China
2, Oceanic basalts
Through the participation in International Ocean Discovery Project (IODP), we commenced researches on source compositions and deep processes of OIB samples which from Hawaii Islands, Louisville seamount chain and South China Sea seamounts (Fig. 2). Furthermore, based on these oceanic samples, the study of magnesium (Mg) isotopic geochemistry has been undertaken.
Figure 2. The distribution diagram of our oceanic samples