![]() RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 8, ES3004, doi:10.2205/2006ES000205, 2006
The geologic structure of the Akkermanovka fragment of the Khabarny Massif ophiolite association (South Ural)A. A. Razumovskiy Geological Institute, Russian Academy of Sciences, Moscow, RussiaAbstract
[1] Using the results of geological mapping, including the petrostructural and petrochemical data,
available, as well as the results of the previous researchers, a composite characteristic is offered for the
geologic structure of the Akkermanovka fragment of the ophiolite sequence of the Khabarny Massif (South
Ural). The position of this fragment in the enclosing structure is shown, and the structure of its paleooceanic
crust rocks is discussed. The plutonic rock complex is distinguished by the unified layering from the
olivine pyroxenite-wehrlite to olivine gabbro - gabbronorite. The linear banding folds show the NW strike
and predominant gentle and intermediate dip angles of their limbs. The general bedding is violated by late
gabbronorite and pyroxenite veins. The composition of the gabbro-"pegmatites" (the latest rocks)
correlates with the composition of the enclosing rocks. The root zone of the dike complex is almost
completely absent. The screen distribution shows the discrete distribution of the layered rock complex in
the mantle tectonites. The sheeted dike complex is characterized by acid magmatism, expressed in the
presence of veins and stocks of different sizes and also by the granitoid material filling the matrix of the
magmatic breccias. These rock complexes seem to have been formed under the conditions of a
supra-subduction marginal-sea basin. Spreading took place under the conditions of a deficient magma
budget and was marked by the existence of numerous totally or partly synchronous extension axes, both
differing in the direction of the spreading block vector. The upper age limit of this process is assumed
to be Famennian (366
Received 25 May 2006; revised 18 June 2006; accepted 2 August 2006; published 20 August 2006. Keywords: Ophiolites, oceanic crust, spreading, layered rocks, sheeted dikes, Khabarny Massif, Akkermanovka rock association, South Ural. Index Terms: 1021 Geochemistry: Composition of the oceanic crust; 1036 Geochemistry: Magma chamber processes; 3042 Marine Geology and Geophysics: Ophiolites; 3643 Mineralogy and Petrology: Layered magma chambers. ![]() Citation: (2006), The geologic structure of the Akkermanovka fragment of the Khabarny Massif ophiolite association (South Ural), Russ. J. Earth Sci., 8, ES3004, doi:10.2205/2006ES000205. Copyright 2006 by the Russian Journal of Earth SciencesPowered by TeXWeb (Win32, v.2.0). |