scholarly journals Geochemistry, petrogenesis, zircon U Pb geochronology and Sr Nd isotopic composition of Kuh-e-Shah volcanic rocks: Implications for an active continental margin along with eastern Iran during the Paleogene

Lithos ◽  
2020 ◽  
Vol 378-379 ◽  
pp. 105778
Author(s):  
Abbas Etemadi ◽  
Samaneh Nadermezerji ◽  
Mohammad Hassan Karimpour ◽  
Azadeh Malekzadeh Shafaroudi ◽  
José Francisco Santos ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Continental Margin ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Eastern Iran ◽  
Nd Isotopic Composition

Andesite Geochemistry Features of Late Triassic Tumugou Formation, in Zhongdian, Yunnan Province

2012 ◽  
Vol 524-527 ◽  
pp. 16-23
Author(s):  
Jian Guo Huang ◽  
Run Sheng Han ◽  
Ren Tao ◽  
Zhi Qiang Li
Keyword(s):  
Trace Element ◽  
Volcanic Rock ◽  
Continental Margin ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Distribution Patterns ◽  
Island Arc ◽  
Late Triassic ◽  
Magma Source ◽  
Volcanic Arc

The Late Triassic Tumugou Formation volcanic rocks which belongs to typical island arc volcanic rocks in southern end of Yidun island arc belt is located at the eastern of the Zhongdian ,NW Yunnan, SW China. The volcanic rocks can be divided into three categories:andesitic basalt, andesite, quartz andesite, etc. Through geochemical analysis the major elements, rare earth ele and trace element in volcanic rocks, SiO255.18-57.59×10-2,TiO21.16-1.45×10-2,Na2O+K2O5.11-8.05×10-2.consider it is calc-alkaline- alkaline Series of high-K andesite, volcanic may be controlled by the crystal fractionation of magma.Rb31.50-101×10-6,Ba1310-12300×10-6,Nb/Ta11.4-15.5,REE166.07-240.78×10-6,δEu0.74-1.00,REE distribution patterns show oblique to the HREE side and enrichment in LREE .Eu anomaly is not obvious. It is can see from the relevant figure about trace element, it is very similar in magmatic distribution patterns between volcanic rock and Volcanic-arc rock, indicating that the volcanic in this area may be formed in volcanic-arc environment. From east to west, Magma source depth have regular change with the really thickness of mainland shell. Explain that Tumugou Formation volcanic rock is subduction by Ganzi- Litang Ocean basin from east to west. Hongshan-Ousaila region of eastern edge of Zhongdian is the volcanic island arc system during the passive continental margin into an active continental margin.

scholarly journals Evidence from the Kyrenia Range, Cyprus, of the northerly active margin of the Southern Neotethys during Late Cretaceous–Early Cenozoic time

2011 ◽  
Vol 149 (2) ◽  
pp. 264-290 ◽  
Author(s):  
ALASTAIR H. F. ROBERTSON ◽  
KEMAL TASLI ◽  
NURDAN İNAN
Keyword(s):  
Continental Margin ◽  
Carbonate Platform ◽  
Middle Eocene ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Basaltic Rocks ◽  
Tectonic Model ◽  
The North ◽  
Basic Volcanic ◽  
Upper Maastrichtian

AbstractSedimentary geology and planktonic foraminiferal biostratigraphy have shed light on the geological development of the northern, active continental margin of the Southern Neotethys in the Kyrenia Range. Following regional Triassic rifting, a carbonate platform developed during Jurassic–Cretaceous time, followed by its regional burial, deformation and greenschist-facies metamorphism. The platform was exhumed by Late Maastrichtian time and unconformably overlain by locally derived carbonate breccias, passing upwards into Upper Maastrichtian pelagic carbonates. In places, the pelagic carbonates are interbedded with sandstone turbidites derived from mixed continental, basic volcanic, neritic carbonate and pelagic lithologies. In addition, two contrasting volcanogenic sequences are exposed in the western-central Kyrenia Range, separated by a low-angle tectonic contact. The first is a thickening-upward sequence of Campanian–Lower Maastrichtian(?) pelagic carbonates, silicic tuffs, silicic lava debris flows and thick-bedded to massive rhyolitic lava flows. The second sequence comprises two intervals of basaltic extrusive rocks interbedded with pelagic carbonates. The basaltic rocks unconformably overlie the metamorphosed carbonate platform whereas no base to the silicic volcanic rocks is exposed. Additional basaltic lavas are exposed throughout the Kyrenia Range where they are dated as Late Maastrichtian and Late Paleocene–Middle Eocene in age. In our proposed tectonic model, related to northward subduction of the Southern Neotethys, the Kyrenia platform was thrust beneath a larger Tauride microcontinental unit to the north and then was rapidly exhumed prior to Late Maastrichtian time. Pelagic carbonates and sandstone turbidites of mixed, largely continental provenance then accumulated along a deeply submerged continental borderland during Late Maastrichtian time. The silicic and basaltic volcanogenic rocks erupted in adjacent areas and were later tectonically juxtaposed. The Campanian–Early Maastrichtian(?) silicic volcanism reflects continental margin-type arc magmatism. In contrast, the Upper Maastrichtian and Paleocene–Middle Eocene basaltic volcanic rocks erupted in an extensional (or transtensional) setting likely to relate to the anticlockwise rotation of the Troodos microplate.

scholarly journals Shrimp U-Pb age and Sr-Nd isotopes of the Morro do Baú mafic intrusion: implications for the evolution of the Arenópolis volcano-sedimentary sequence, Goiás Magmatic Arc

2003 ◽  
Vol 75 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Márcio M. Pimentel ◽  
Maria Helena B. M. Hollanda ◽  
Richard Armstrong
Keyword(s):  
Isotopic Composition ◽  
Volcanic Rocks ◽  
Sedimentary Sequence ◽  
Calc Alkaline ◽  
Nd Isotopes ◽  
Magmatic Arc ◽  
Minimum Age ◽  
The Mean ◽  
Age Limit ◽  
Nd Isotopic Composition

The Arenópolis volcano-sedimentary sequence is located in the southern part of the Goiás Magmatic Arc and includes a ca. 900 Ma calc-alkaline arc sequence made of volcanic rocks ranging in composition from basalts to rhyolites, metamorphosed under greenschist to amphibolite facies. Small calc-alkaline gabbro to granite sub-volcanic bodies are also recognized. The Morro do Baú intrusion is the largest of these intrusions, and is made of gabbros and diorites. Zircon grains separated from one gabbro sample and analyzed by SHRIMP I yielded the mean 206Pb/238U age of 890 +/- 8 Ma, indicating that the intrusion is roughly coeval or only slightly younger than the Arenópolis volcanics. Contrary to the metavolcanics, which are juvenile, the Nd isotopic composition of the Morro do Baú gabbro indicates strong contamination with archean sialic material (T DM of 2.8 Ga and EpsilonNd(T) of -9.7), represented in the area by an allochthonous sliver of archean/paleoproterozoic gneisses (Ribeirão gneiss) which are the country-rocks for the gabbro/dioritic intrusion. The emplacement age of ca. 890 Ma represents a minimum age limit for the tectonic accretion of the gneiss sliver to the younger rocks of the Arenópolis sequence. The data suggest that this happened early in the evolution of the Goiás Magmatic Arc, between ca. 920 and 890 Ma.

scholarly journals Tataan Tektonika Batuan Gunung Api di Komplek Adang Kabupaten Mamuju Provinsi Sulawesi Barat

EKSPLORIUM ◽  
2015 ◽  
Vol 36 (1) ◽  
pp. 31
Author(s):  
I Gde Sukadana ◽  
Agung Harijoko ◽  
Lucas Donny Setijadji
Keyword(s):  
Volcanic Rock ◽  
Continental Margin ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Radiation Dose Rate ◽  
X Ray ◽  
Complex Process ◽  
Radioactive Mineral ◽  
Tectonic Settings

Kompleks batuan gunung api Adang di daerah Kabupaten Mamuju, Sulawesi Barat secara lebih detail dapat dikelompokkan menjadi tujuh, yaitu kompleks Tapalang, Ampalas, Adang, Malunda, Karampuang, Sumare, dan Labuan Rano. Komplek Adang merupakan salah satu komplek gunungapi utama yang masih dapat diidentifikasi bentukan morfologinya dengan baik. Komplek ini  tersusunatas batuan gunung api basa hingga intermediet yang memiliki nilai laju dosis radiasi cukup tinggi yang disebabkan oleh kandungan mineral radioaktif di dalamnya. Keterdapatan mineral radioaktif pada batuan basaltik-andesitik belum pernah dijumpai di Indonesia sehingga hal ini menjadi sangat menarik untuk dilakukan penelitian terutama tataan tektonika pembentukan batuan komplek gunung api tersebut. Tujuan penelitian ini adalah untuk menentukan tipologi magmatik yang terkait dengantataan tektonikanya dengan pendekatan  geokimia batuan gunung api menggunakan analisis X-Ray Fluorescence (XRF). Batuan gunung api Adang merupakan hasil dari proses vulkanisme suatu komplekgunung api yang memiliki pusat erupsi dan beberapa kubah lava. Batuan tersebut tersusun atas batuan trachyte-phonolite, dengan afinitas magmatiknya ultrapotasik, Dari data tersebut dapat diinterpretasi bahwa tataan tektonika magmatologinya adalah active continental margin(ACM). Magma asal yang membentuknya dari aktivitas gunung apinya dipengaruhi oleh kerak benua mikro barat daya (South West/SW) Sulawesi. Adang volcanic complexlocated in Mamuju Region, West Sulawesi can be grouped more detail into seven complexes that are Tapalang, Ampalas, Adang, Malunda, Karampuang, Sumare, and Labuan Rano. Adang complex is one of the main volcanic complexes that still can be identified with good morphological formations. This complex is composed of alkaline volcanic rocks with basic to intermediates composition that have high value of radiation dose rate caused by their radioactive mineral content. Radioactive mineral occurrences on the basaltic-andesitic rocks has never been found in Indonesia, so it becomes very interesting to do research mainly tectonic settings of the volcanic rock complex formation. The purpose of this study is to determine magmatiic typology related with the tectonic setting based on volcanic rock  geochemistry using X-Ray Fluorences (XRF) analysis. Adang volcanic rock is the result of a complex process of volcanism having a volcanic center and several lava domes. They are composed of phonolite to dacite rock, with ultrapotassic affinity, interpretation of data concluded that tectonic setting of magmatism formed in active continental margin (ACM). Magmatism source from vulcanic activities influenced by South WestSulawesi micro-continental crust.

Eocene development of the northerly active continental margin of the Southern Neotethys in the Kyrenia Range, north Cyprus

2013 ◽  
Vol 151 (4) ◽  
pp. 692-731 ◽  
Author(s):  
ALASTAIR H.F. ROBERTSON ◽  
GILLIAN A. McCAY ◽  
KEMAL TASLI ◽  
AŞEGÜL YILDIZ
Keyword(s):  
Debris Flow ◽  
Subduction Zone ◽  
Continental Margin ◽  
Middle Eocene ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Late Eocene ◽  
Calcareous Nannofossils ◽  
The North ◽  
Thrust Sheets

AbstractWe focus on an active continental margin related to northwards subduction during the Eocene in which sedimentary melange (‘olistostromes’) forms a key component. Maastrichtian – Early Eocene deep-marine carbonates and volcanic rocks pass gradationally upwards into a thick succession (<800 m) of gravity deposits, exposed in several thrust sheets. The lowest levels are mainly siliciclastic turbidites and debris-flow deposits. Interbedded marls contain Middle Eocene planktonic/benthic foraminifera and calcareous nannofossils. Sandstones include abundant ophiolite-derived grains. The higher levels are chaotic debris-flow deposits that include exotic blocks of Late Palaeozoic – Mesozoic neritic limestone and dismembered ophiolite-related rocks. A thinner sequence (<200 m) in one area contains abundant redeposited Paleogene pelagic limestone and basalt. Chemical analysis of basaltic clasts shows that some are subduction influenced. Basaltic clasts from unconformably overlying alluvial conglomerates (Late Eocene – Oligocene) indicate derivation from a supra-subduction zone ophiolite, including boninites. Taking account of regional comparisons, the sedimentary melange is interpreted to have formed within a flexurally controlled foredeep, floored by continental crust. Gravity flows including large limestone blocks, multiple debris flows and turbidites were emplaced, followed by southwards thrust imbrication. The emplacement was possibly triggered by the final closure of an oceanic basin to the north (Alanya Ocean). Further convergence between the African and Eurasian plates was accommodated by northwards subduction beneath the Kyrenia active continental margin. Subduction zone rollback may have triggered collapse of the active continental margin. Non-marine to shallow-marine alluvial fans prograded southwards during Late Eocene – Oligocene time, marking the base of a renewed depositional cycle that lasted until latest Miocene time.

Transition from a passive to active continental margin setting for the NE Asian continental margin during the Mesozoic: Insights from the sedimentary formations and paleogeography of the eastern Jiamusi Massif, NE China

2021 ◽  
Author(s):  
Yini Wang ◽  
Wenliang Xu ◽  
Feng Wang
Keyword(s):  
Continental Margin ◽  
Lower Cretaceous ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Lower Jurassic ◽  
Pacific Plate ◽  
Upper Triassic ◽  
Passive Continental Margin ◽  
Ne China ◽  
Margin Setting

The Mesozoic tectonic evolution of the NE Asian continental margin has received much attention in recent years. However, previous studies focused mainly on the petrogenesis of igneous rocks and their relationship with Mesozoic tectonics, and there have been few studies of the Mesozoic sedimentary formations of the NE Asian continental margin. We combined zircon U-Pb ages with Hf isotopic and biostratigraphic data to reconstruct the Mesozoic paleogeography of the NE Asian continental margin. The results indicate that Mesozoic strata of the eastern Jiamusi Massif, NE China, include the Upper Triassic Nanshuangyashan Formation (Norian), Lower Jurassic volcanic rocks, and Lower Cretaceous Longzhaogou Group. The Upper Triassic Nanshuangyashan Formation consists of a suite of alternating marine and terrestrial sedimentary rocks with abundant fossils that formed in a passive continental margin setting. The Lower Jurassic strata comprise a suite of calc-alkaline volcanic rocks that include basaltic andesites, andesites, and rhyolites that formed in an active continental margin setting related to initial subduction of the Paleo-Pacific Plate beneath Eurasia. The Lower Cretaceous Longzhaogou Group belong to alternating marine and terrestrial sedimentary formations that formed in an active continental margin setting related to subduction of the Paleo-Pacific Plate. Here, we integrate these data to reconstruct the Mesozoic tectonic history of the NE Asian continental margin, which comprises a Late Triassic passive continental margin, the initiation of subduction of the Paleo-Pacific Plate in the Early Jurassic, and westward subduction and rollback of the Paleo-Pacific Plate in the Early Cretaceous.

scholarly journals Paleozoic and Early Mesozoic terrigenous deposits of the South-West Primorye: material composition and origin

2020 ◽  
Author(s):  
А.И. МАЛИНОВСКИЙ
Keyword(s):  
Continental Margin ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Source Area ◽  
Material Composition ◽  
Clastic Material ◽  
Power Sources ◽  
Early Mesozoic ◽  
South West

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.

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