Global major events in Miocene and its significance: Revelation from data mining

The GEOROC (Geochemistry of Rocks of the Ocean-sand Continents) database is a comprehensive global petrological database and it is constantly updated and available online to users around the world. Based on this database, we analyze the age data of the global Cenozoic igneous rocks including convergent margin andesite and basalt, continental rift andesite and basalt, ocean island andesite and basalt, adakite, and so on. Statistical analysis reveals that the global magmatism either became active in the Miocene or peaked in the Miocene. Magmatic rocks formed in different tectonic settings represent different geological effects: convergent margin magmatic rock suggests the speed up of subduction; the huge eruption of rift andesite and basalt indicates the occurrence of plate extension; the sharp increase of ocean island andesite and basalt indicates an abnormally active lower mantle, which brings materials from the lower mantle into the crust; a large scale of medium-acid magmatic rock represents the lower crust at high temperature and the asthenosphere mantle strongly upwelling, which leads to the crust intensely reforming; adakite is usually related to strongly tectonic pressing and results in crustal thickening in these areas. In addition, there was a series of significant events in the Miocene. For instance, the Tibetan Plateau rapidly uplifted in the middle Miocene, leading to the formation of the Loess Plateau; the Andean Mountains rose abruptly probably during 8–3 Ma; Tethys dried up from 20–5 Ma, which may have been a cause of the global desertification; the development of the western Pacific marginal sea basins mainly occurred during the late Oligocene to early Miocene. We tried to explain the connection among all of these events as follows. Generally, magmatism usually goes with tectonic activities, and their interaction may change the paleogeography, paleoclimate, and paleoenvironment. The accelerated motion of the Pacific Plate in the Miocene could have thickened or raised the crust, resulting in the formation of the Andean mountains. The interaction between the Indian plate and Eurasian plate in the Miocene induced the speedy uplifting of the Tibetan Plateau. The new mountain and plateau reformed the original landscape and landform, which made these areas easily suffer weathering and erosion, and the resulting sediments were taken into global ocean basalts with ocean currents. As a result, the accumulation rate of oceanic sediments would have risen quickly. Furthermore, the upraising of the Andean and Tibetan Plateaus also influenced the general atmospheric circulation, which ultimately changed the environment; this might be an important reason why primitive man originated from the Miocene. In addition, as for China, the strike-slip fault in the Red River, the expansion of the South China Sea, and the formation of the Taklimakan Desert may be more or less related to the magmatism in the Miocene. There remain a number of problems to explore. Therefore, studying the interrelationship among magmatism, tectonic activity, climate, and environment in the Miocene should be a priority for geoscience workers in the present and future. Besides, scientific research is gradually entering the big data era, and geological science is no exception. The primary characteristic of big data research is not how big the data is but how creative the thought is. In this study, we took advantage of all available data to investigate the relationship among the data sets. The findings reveal that data mining with a global database can provide new insights and new lines of inquiry for scientific research in the future.