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MICHIHEI HOSHINO THE HISTORYOFMICRO-EXPANDING EARTH -History of the Earth from viewpoint of Sea Level Rise-  Published by E. G. Service Press, Sapporo, Japan. 2014. 234p. press@egs.co.jp. ISBN 978-4-9903950-5-6.Price: JY5,000 (about U$45) plus tax and shipping charges. Available only in hard copy format. Reviwed by Masahiro SHIBA The author, Michihei HOSHINO, Emeritus Professor of Tokai University and Ocean University of China, is now 91 years old. This book is his life work, which compiled into this book all the fruits of many years of his geotectonic study from viewpoint of sea level rise. First, he studied the sediments of the continental shelf around Japan, and showed clearly that the sea level of the last glacial epoch was about 100 m lower than the present. Next, he hypothesized that submarine canyons originated by the submergence caused by a 2,000 m sea level rise after the late Miocene. This hypothesis was proved by the discovery of Messinian Evaporates in the western Mediterranean basins. In early 1970s he commented that the oceanic trench is not the place of crustal depression but is an abandoned furrow left behind on the uplifting of ocean side crust. Since the summit depth of guyots which have the coral reef of the middle Cretaceous in trenches are 4,000 m, he presumed that the sea level of the mid Cretaceous was 4,000 m lower than the present. He explains that by extensive uplift of crust including ocean floor and sea level rise by the tholeiitic basalt activity of the asthenosphere origin after the Jurassic Period, the present continents and oceans have formed. In 1991, he reported that the Baikalian and Variscan remnant basins, which have ancient peneplain (sea level) basement, and the peneplains of the Baikalian remnant basins are about 11 km below the present sea level. And he divided the history of the Earth into three stages; the Granitic Stage (Archean), the Transitional Stage (Proterozoic and Paleozoic), and the Basaltic Stage (Mesozoic and Cenozoic). From these studies he now believes that “the fundamental problem of geology is the crustal uplifting (micro-expansion of the Earth)”, and that crustal “subsidence” is a fictitious phenomenon and the true process is crustal submergence by the rising sea level due to crustal uplift. For me it is considered to be a very reasonable view. In this book, the history of the crust and eustasy is shown from the Earth creation to the present. It is dominated by crustal uplifting and rising sea level by less than 50 km. Each time the crust was formed, the position on the Earth surface upheaved, and so did the Earth surface topography. This book tells in a dramatic way the history of micro-expansion of the Earth as follows: Eucrite chondorite gathered at the earliest stage of Earth’s birth, followed by enstatite chondorite, which formed the primeval Earth surface. The former formed the asthenosphere and the latter formed the uppermost part of the mantle (lower lithosphere). In the Granite Stage (Archean), the lower lithosphere differentiated into atmosphere, hydrosphere and granitic crust. The tectonic pattern of this stage consisted of domes of concentrically arranged granitoids and gneisses, which were surrounded by greenstone belts. The diameter of the domes attained 100 km to 800 km. In the Transitional Stage (Proterozoic and Paleozoic), the activities of the layered igneous body that had been produced by the mixing of the Mg-rich ultra-mafic and Ca-rich mafic magmas formed elevated plateaus. The high temperature atmosphere that contained carbon dioxide and water steams in the Proterozoic Era eroded the elevated plateau violently, and built the vast peneplains. Then, sediments filled the seas which were surrounded by the plateaus. As sea level rose, the plateau region became covered by shallow seas. The thick layers of Stromatolites deposited in the shallow seas, forming dolomite, and emitted a vast amount of oxygen into the atmosphere simultaneously. The seas between the plateaus were filled with thick sediments supplied from elevated plateaus, having become an incipient geosyncline. The bottom of many present-day geosynclinal belts is situated at a depth of about 50 km beneath the present sea level. Hoshino considers that this depth was at the sea bottom in the late Archean. In the latest Proterozoic (Baikalian Stage), one billion years before the present, sea level had risen to about 11 km below the present level, and then the peneplains had been formed everywhere on the Earth. The greater part of these peneplains constitute the present Moho surface under the ocean floor. In the case of wide geosynclinal basins, when the central plateau, a composite of old and young plateaus, was elevated, reverse faults in the shape of a bidirectional petal were produced. After that, as the reverse faults have remained active, geosynclinal rock formations were pushed out above the rims of the peneplanated plateaus (Moho surface under the ocean floor). The marginal sea (central plateau) - island arc (surrounding the geosynclinal-orogenic belt) - trench (compression zone) system was formed by this process. In the narrow geosynclinal basin without a central plateau, the elevation of the geosynclinal-orogenic belts has no extrusive rocks accompanied by reverse faults. The oceanic ridges consist of such geosynclinal-orogenic belts. The Basaltic Stage, the latest stage in the history of the Earth, from the Mesozoic Era to the present, is characterized by the activity of Ca-rich basaltic plutonic magmas. This resulted in the upheaval of land and ocean basins (epirogenic movement) with rising sea level. The basaltic plutonic rocks, mainly high-temperature and high-pressure magmas originated from the asthenosphere, increased in volume and produced linear deep faults along the weak belts of the lithosphere (Archean lineaments). They rose and intruded under the plateau basement by spreading horizontally. Magmas erupted on continents are plateau basalts, and those extruded on the sea floors covered the peneplanated upper Proterozoic basement and formed the present-day oceanic crust. The deformed and elevated sedimentary layers formed island arcs and ridges. Due to the rise of the ocean basin floors caused by the addition of ocean basaltic layers since the Mesozoic, sea level has risen by 6 km. The feature of the tectonics of the Basaltic Stage is characterized by fault blocks and tilting, and especially, it evolved in the last period of the Basaltic Stage into the period with distinctive characteristics, called the Neotectonic Period, and formed the geographical features as seen on the present surface of the Earth. Hoshino refers to the history of the Earth in this book; “The history of the Earth is neither an uniformitarian-cyclic-concept (Charles Lyell) nor dialectic evolutionary process (ZHANG Wenyou, 1984), but it may be the developmental process from birth to death. When shall the death of the Earth arrive? Is it the day of the ending of the driving force for an expanding Earth, or the day of out-burst of stable Si-combined crust? The story of the death day of the Earth is far future, because the half-life of 232Th is 14.1 billion years.” Zhang, W.J. 1984. An introduction to Fault-block tectonics. Petrol. Industr. Press, Beijing, 385p. I Origin of the Earth 1. Condensation of the solar nebula 2. Peridotite and basalt 3. Driving force for the development of the Earth II The Significance of sea water in geological science 1. Origin of sea water 2. Composition of sea water 3. Base level 4. Eustasy 5. Transgression and regression 6. Unconformity III The Granitic Stage 1. Formation of the upper Earth’s crust 2. Structural characteristics of the Granitic Stage IV The Transitional Stage 1. Uplift of platform 2. Remnant basin 3. Cap layers of the platforms 4. Geosyncline and orogeny 5. Rift valley 6. Aulacogen 7. Oceanic ridge and sea-mount chain 8. Ophiolite V The Basaltic Stage 1. What is the Basaltic Stage? 2. Distribution of the flood basalts 3. Petrology of the oceanic basalt 4. The granite in the Basaltic Stage 5. Crustal uplift in the Neotectonic Period 6. Oceanic trenches 7. Sea level rise in the Basaltic Stage 8. Land Bridges VI Concluding remarks |