Sectoral tectonics of the Earth's eastern hemisphere and its crucial role in localization of giant ore deposits, prominent rift systems and large flood basalt provinces
Kochemasov, G. G.
published: Jan 1, 1998
ArtNo. ESP136000603007, Price: 19.00 €
A number of the solar system's planets and satellites (e.g. Venus, Mars, Earth, Moon, 10, Miranda) show a sectoral structure of their continental hemispheres (Kochemasov, 1993, 1994a). On the Earth this structure is well developed in its eastern hemisphere where intersection of two planetary weakness zones (seams) forms 4 sectors (fig.): two opposite differently uplifted (Afro-Mediterranean /7+8/ + +, Asian /3+4/ +) and separating them two opposite differently subsided ones (Eurasian /1 +2/ -, Indoceanic /5+6/, - -). An area of intersection of the seams roughly coincides with the Pamirs-Hindukush mountain massif (it is significant that antipodal to this massif is Easter lsl. - a prominent high on oceanic floor of the western hemisphere). This sectoral morphotectonic division is of fundamental nature because it has through character and can be traced down to the core-mantle boundary (CMB). Depressions (lows) of the CMB correspond to the uplifted sectors, bulges (highs) to the subsided ones, i.e., there is a mirror reflection (Morelli and Dziewonski, 1987). Geoid shape, depending on mantle density at several hundred kilometers depth, has a direct relation with the relief: positive geoid anomalies correspond to the uplifted sectors, negative ones to the subsided sectors. The mantle-crust boundary is raised in the subsided and dropped in the uplifted sectors. The upper mantle density is increased in the subsided sectors (gravimetry data). The largest geoid minimum - Indoceanic, -112 m - occurs in strongly subsided Indoceanic sector (- -). Peculiarities of magmatism and ore deposits directly depending on tectonics show correlation with the sectors.