Is there a pyrolitic lower mantle transition zone?

Yajie Zhao1, Zhongqing Wu1, Shangqin Hao1,2, Wenzhong Wang1,3, Xin Deng1 and Jian Song1, (1)University of Science and Technology of China, School of Earth and Space Sciences, Hefei, China, (2)University of California San Diego, La Jolla, CA, United States, (3)Carnegie Institution for Science, Earth and Planets Laboratory, Washington, DC, United States