scholarly journals THE LOWER SILURIAN TERRIGENOUS DEPOSITS OF THE LAOELING-GRODEKOVO TERRANE (SOUTH PRIMORYE): MATERIAL COMPOSITION AND FORMATION SETTINGS

Author(s):  
A.I. Malinovsky ◽  
◽  
V.V. Golozubov ◽  

This paper studies the original results of the material composition analysis of the Early Silurian terrigenous deposits of the Kordonka formation of the Paleozoic – Early Mesozoic Laoeling-Grodekovo terrane of the South Primorye. The research is aimed at reconstructing paleogeodynamic setting of the deposition of sediments of the formation, and determining the type and mother rock composition of the feed sources based on the complex genetic interpretation of the material composition of rocks. It was established that mineralogically and geochemically formation of the rocks correspond to the typical graywackes and represent petrogenic or “first cycle” rocks formed mainly through the source rock failure. They are characterized by a low maturity, low lithodynamic recycling rate of mother rocks and their rapid burial. The interpretation of the results of the complex study of the material composition of the rocks was carried out on the basis of its comparison with the compositions of ancient rocks and modern sediments formed in the well-known geodynamic settings. The obtained data indicate that deposits of the Kordonka formation accumulated in a sedimentary basin connected with an oceanic island arc. Being built by basic and intermediate volcanic rocks as well as by igneous and sedimentary rocks that constituted its base, this island arc was the source area that supplied clastic material to the aforementioned sedimentary basin.

1982 ◽  
Vol 19 (6) ◽  
pp. 1275-1294 ◽  
Author(s):  
B. D. Ricketts ◽  
Michael J. Ware ◽  
J. Allan Donaldson

The Middle Precambrian Flaherty Formation consists of a thick sequence of volcanic rocks of both effusive and explosive origin, derived from a source area west of the Belcher Islands. The effusive volcanic facies are made up of thick, massive lava flows, some of which are compound, that are intercalated with thick lenticular units of pillowed lava. Facies of explosive origin, the volcaniclastic rocks, are a product of phreatic and phreatomagmatic eruptions. A variety of volcaniclastic facies are recognized on the basis of bed geometry, sedimentary structures, and textural characteristics, and include: thinly bedded tuffs and lapillistones that were deposited by fallout from vertical ash columns (some tuffs contain accretionary lapilli and hence originated from subaerial eruption columns); pillow talus deposits (hyaloclastites) resulting from the rapid quenching of lava in water; volcaniclastic turbidites representing relatively deep-water resedimented tephra; and a single massive pyroclastic flow that was emplaced during a single depositional event, and may have been derived from a Plinian eruption or series of Surtseyan eruptions. Systematic variations in these volcaniclastic facies, for example an increase in the proportion of turbidite units towards eastern Belcher Islands, indicate that water depth increased eastward.Based on physical volcanological aspects, the Flaherty Formation is compared with some modern and ancient analogues. The style of volcanism envisaged for the Flaherty is similar to that of Iceland, or possibly to an immature stage of island arc development. From a tectonic viewpoint, the comparison with Iceland is problematical because it is part of an oceanic regime, whereas the Flaherty Formation is more closely related to an ensialic regime. Direct comparison with an island arc also is difficult because little is known about volcanic facies relationships in the early growth stages of such arcs.


Author(s):  
А.И. МАЛИНОВСКИЙ

Рассматриваются результаты изучения вещественного состава палеозойских–раннемезозойских терригенных отложений Лаоелин-Гродековского террейна (юго-западное Приморье). Цель исследования – палеогео­динамическая реконструкция обстановок формирования отложений изученных свит, а также определение типов и породных составов их источников питания. Установлено, что отложения свит существенно различаются по вещественному составу, следовательно, они формировались в различных палеогеодинамических обстановках. Отложения кордонкинской свиты накапливались в бассейне, связанном с океанической островной дугой, при этом областью их питания была сама дуга, сложенная основными и средними вулканитами, а также магматическими и осадочными образованиями, входившими в состав ее фундамента. Накопление решетниковской свиты происходило в бассейнах, расположенных на пассивной континентальной окраине. Источниками вещества служили участвовавшие в строении этой окраины кратоны и краевые части рифтов, сложенные гранитоидами, метаморфическими и осадочными породами. Тальминская свита формировалась на активной континентальной окраине в бассейнах рифтогенного происхождения. Источниками кластического материала были краевые части этих рифтов, сложенные кислыми и средними изверженными, а также метаморфическими породами. Полученные результаты позволяют рассматривать Лаоелин-Гродековский террейн как аккреционную призму, сложенную силурийскими, пермскими и триасовыми образованиями, сформировавшимися в различных палеогеодинамических обстановках. Results of material composition study of Paleozoic–Early Mesozoic terrigenous deposits of Laoeling-Grodekovo terrane (South-West Primorye) are collected. The purpose of the study was to reconstruct paleogeodynamic setting of deposits of studied formations, as well as to determine the types and rock compositions of their power sources. It was established that the deposits differ significantly in their material composition and, accordingly, were formed in different paleogeodynamic settings. Deposits of the Kordonka formation accumulated in the basin associated with the oceanic island arc, while the source area was the arc itself, composed of basic and intermediate volcanic rocks, as well as igneous and sedimentary formations that were part of its foundation. The accumulation of the Reshetnikovka formation took place in basin located on the passive continental margin. The sources of the matter were the cratons and marginal parts of rifts participating in the structure of this margin, composed of granitoids, metamorphic, and sedimentary rocks. The accumulation of the Tal’mi formation took place on the active continental margin in the basins of riftogenic origin. The sources of the clastic material were the marginal parts of these rifts, composed of acidic and intermediate igneous Laoeling-Grodekovo terrane as an accreationary prism formed by Silurian, Permian and Triassic deposits, which were formed in various paleogeodynamic settings.


2018 ◽  
Vol 37 (2) ◽  
pp. 607-625 ◽  
Author(s):  
Haitao Sun ◽  
Dakang Zhong ◽  
Weijia Zhan

To explain the strong spatial heterogeneity of volcanic reservoirs porosity in the Songliao Basin and provide new ideas for predicting good volcanic reservoirs in other similar basins, the relationship between the pore evolution process and lithology of volcanic reservoirs has been described in this article. With the description and interpretation of core, thin section, scanning electron microscope, and the results of mercury injection experiment, this article clarifies the lithology, pore types, and pore structure features of the volcanic reservoirs in the Songliao Basin. The rocks of volcanic reservoirs in study area contain pyroclastic rock and volcanic lavas. The most common lithologies are rhyolite, volcanic breccia, and volcanic tuff. The pore size, morphology, and structure vary greatly between these three lithologies, the reason of which we think is the different volcanic eruption process as well as rock composition and its structure. The digenetic evolution of rhyolite includes gas dissipation of magmatic condensation; vesicles fulfilling by hydrothermal fluid; kaolinization and sericitization of feldspar phenocrysts; carbonation, devitrification, and recrystallization of felsic matrix; and finally, the dissolution of feldspar phenocrysts and felsic matrix. As for volcanic breccia, it usually go through the compaction, quartz and calcite filling the original pores between volcanic breccias, and dissolution of mineral debris together with tuff matrix. Similar with the rhyolite, volcanic tuff also undergoes the carbonation and kaolinization of felsic matrix, the dissolution of feldspar and felsic matrix, and compaction. Due to these comprehensive processes, a comprehensive analysis of volcanic rock lithology, which can indicate lithology distribution vertically and horizontally, is very necessary during volcanic reservoirs evaluation and prediction. These detailed analyses will help explorers to find potential reservoirs by distinguishing the diagenetic evolution and pore characteristic of volcanic reservoirs.


Lithos ◽  
2017 ◽  
Vol 290-291 ◽  
pp. 228-252 ◽  
Author(s):  
Yamirka Rojas-Agramonte ◽  
Ian S. Williams ◽  
Richard Arculus ◽  
Alfred Kröner ◽  
Antonio García-Casco ◽  
...  

2019 ◽  
Vol 27 (1) ◽  
pp. 57-78
Author(s):  
D. V. Alexeiev ◽  
Yu. S. Biske ◽  
A. V. Djenchuraeva ◽  
B. Wang ◽  
O. L. Kossovaya ◽  
...  

The field revision of the Carboniferous and Lower Permian stratigraphy of the northern Bogdashan (South Junggar, Northwest China) shows that the Lower to Middle Carboniferous island arc volcanic rocks, widely developed in this region, are overlapped everywhere by carbonate and terrigenous-carbonate sediments, containing occasional lava flows and overlain up the section by thick terrigenous series practically devoid of volcanic rocks. The deposition of limestone occurred at the stage of dying off of a volcanic arc, and the question of their age is of fundamental importance for dating this event. Carbonates are represented by facies of lagoons, shoals, and bioherms that formed on the leveled surface of the arc and on the slopes of the last active volcanoes. Bioherms are Waulsortian mounds and are mainly composed of algal limestones and carbonate mud. There are no framestones composed of corals and sponges (chaetetids) typical of the tropical zone. The facies of shallow crinoid-fusulinid limestones typical of the adjacent territories of the Southern Tien Shan and Tarim are poorly represented. Paleogeographically, the position of bioherms corresponds to the northern boundary of the realm of Pennsylvanian reefs. On the basis of foraminifers, brachiopods, and corals, the age of carbonates is early Moscovian (ca. 315–310 Ma). Cessation of island-arc volcanism, followed by the accumulation of limestone in Bogdashan, occurred sub-synchronously with formation of the West Junggar (Bayingou) suture and may reflect docking of the Bogdashan arc to the Yili active margin of the Kazakhstan continent. Further subsidence of Bogdashan and adjacent regions of the Junggar and Turfan basins, which was somewhat slower at the end of the Carboniferous and more intense in the Early and Middle Permian, may reflect the development of the foreland basin that formed along the northern flank of the Tien Shan orogen. Marine facies were locally preserved in this basin until the Artinskian (ca. 285 Ma), and later the Junggar and Turfan basins lost connection to the ocean and developed in continental environments.


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