Geological Processes in the Baikal Rift Zone: Possible Terrestrial Analogs for the Valles Marineris Region on Mars

Introduction: Recent researches are shedding new lights on the evolution of Valles Marineris and neighboring chaotic terrain and outflow channels. For example , Chapman and Tanaka [1] proposed a hypothesis with an emphasis on magma-ice interactions for the formation of chasmata, interior deposits, chaotic terrain , outflow channels, and surface materials. Terrestrial analog studies are useful in providing examples of processes that may have operated in this complex region on Mars. I here introduce some geological processes of the Baikal Rift Zone in southern Siberia, which could be compared with those in the Valles Marineris region. Many of the proposed geological activities of the Valles Marineris region have occurred also in the Baikal Rift Zone. Therefore, comparisons of these two unique regions on Earth and Mars could provide potentially very rich understanding of how elements such as rift volcanism and climate influence each other, and of the important role hydrology plays in forming landforms. Water in the Baikal Rift Zone: The Baikal Rift Zone including northern Mongolia is a vast land characterized by complex geological history (Figure 1). The geology of this region reflects continental formation processes based on interactions of cratons and arcs [2]. The basement rocks are comprised of ancient passive and active margin terrains as old as the Proterozoic and they were accreted over successively forming foldbelts of sedimentary-volcanic formations. These formations are usually extensively folded and underpinned by a variety of granitic plutons. The Cenozoic Baikal Rift with Lake Baikal occupying in the middle is as deep as 8-9 km with a thick accumulation of sediments filled in and it is one of the deepest active rifts on Earth. The main Baikal Rift is associated by many sub-parallel grabens with volcanism as young as the Holocene. The Tuva volcanic province is the westernmost lava field linked with the Baikal Rift System and the largest lava field in the province is the Azas Plateau. The Tuva volcanic province is related to the South Baikal Hot Spot that forced domal uplifting with the highest altitude above 3000 m a.s.l. at the triple junction of Hovsgol Basin, Tunka valley and Oka-Azas toughs (Figure 1). The compositions of Baikal Rift Zone vol-canics are trachybasalt and basanite [3]. The Azas lava plateau began to form from the Late Pliocene and its volcanism continued to the Holocene. The rift volcanism in the cold and wet climatic regime caused subice volcanism in Siberia. …