The petrogenesis and tectonic setting of lavas from the Baft Ophiolitic Mélange, southwest of Kerman, Iran

1994 ◽  
Vol 31 (5) ◽  
pp. 824-834 ◽  
Author(s):  
Mohsen Arvin ◽  
Paul T. Robinson
Keyword(s):  
Late Cretaceous ◽  
Tectonic Setting ◽  
Tholeiitic Basalt ◽  
Ocean Basin ◽  
Plate Motion ◽  
Geochemical Data ◽  
Ophiolite Complex ◽  
Ophiolitic Mélange ◽  
Lut Block ◽  
Mafic Lavas

A Late Cretaceous ophiolite complex in the Baft area, southwest of Kerman, Iran, is characteristic of the Central Iranian Ophiolitic Mélange Belt, which wraps around the Lut Block. Despite the extensive tectonic disruption of the Baft complex, most ophiolitic lithologies are present and many original igneous contacts are preserved. A lack of cumulate gabbros within the sequence suggests that a large and continuous magma chamber did not exist beneath the Baft spreading axis. Geochemical data confirm the presence of two distinct compositional groups in the mafic lavas: (1) tholeiitic basalt and (2) transitional tholeiitic basalt. The tholeiitic lavas are similar to typical mid-ocean-ridge basalt compositions, whereas the transitional tholeiites are similar to intraplate basalts. The available data suggest that the Baft ophiolite complex formed in a small ocean basin, possibly at or near a ridge–transform intersection. Emplacement may have occurred as a result of conversion of the transform fault to a subduction zone during a change in relative plate motion. A ridge–transform setting is compatible with the intraplate character of some of the transitional basalts, which probably represent off-axis (seamount) magmatism, marked by the absence of cumulate gabbros and the presence of a serpentinite mélange cut by basaltic dykes. The ridge–transform model suggests formation of the ophiolite in a narrow ocean basin separating the Sanandaj-Sirjan microcontinent from the Central Iran Block in Late Cretaceous time.

Cambrian to early Silurian ophiolite and accretionary processes in the Beishan collage, NW China: implications for the architecture of the Southern Altaids

2011 ◽  
Vol 149 (4) ◽  
pp. 606-625 ◽  
Author(s):  
S. J. AO ◽  
W. J. XIAO ◽  
C. M. HAN ◽  
X. H. LI ◽  
J. F. QU ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Island Arc ◽  
Passive Margin ◽  
Granitic Rocks ◽  
Geochemical Data ◽  
Weighted Mean ◽  
Ophiolite Complex ◽  
The North ◽  
Ophiolitic Mélange ◽  
Continental Growth

AbstractThe mechanism of continental growth of the Altaids is currently under debate between models invoking continuous subduction-accretion or punctuated accretion by closure of multiple ocean basins. We use the Yueyashan–Xichangjing ophiolite belt of the Beishan collage (southern Altaids) to constrain the earliest oceanic crust in the southern Palaeo-Asian Ocean. Five lithotectonic units were identified from S to N: the Huaniushan block, a sedimentary passive margin, the structurally incoherent Yueyashan–Xichangjing ophiolite complex, a coherent sedimentary package and the Mazongshan island arc with granitic rocks. We present a structural analysis of the accretionary complex, which is composed of the incoherent ophiolitic melange and coherent sedimentary rocks, to work out the tectonic polarity. A new weighted mean206Pb–238U age of 533 ± 1.7 Ma from a plagiogranite in the Yueyashan–Xichangjing ophiolite indicates that the ocean floor formed in early Cambrian time. Furthermore, we present new geochemical data to constrain the tectonic setting of the Yueyashan–Xichangjing ophiolite. The Yueyashan–Xichangjing ophiolite was emplaced as a result of northward subduction of an oceanic plate beneath the Mazongshan island arc to the north in late Ordovician to early Silurian time. Together with data from the literature, our work demonstrates that multiple overlapping periods of accretion existed in the Palaeozoic in the northern and southern Altaids. Therefore, a model of multiple accretion by closure of several ocean basins is most viable.

Peridotites and basaltic rocks within an ophiolitic mélange from the SW igneous province of Puerto Rico: relation to the evolution of the Caribbean Plate

2016 ◽  
Vol 154 (1) ◽  
pp. 96-118
Author(s):  
NADJA OMARA CINTRON FRANQUI ◽  
SUNG HI CHOI ◽  
DER-CHUEN LEE
Keyword(s):  
Puerto Rico ◽  
Tectonic Setting ◽  
Geochemical Data ◽  
Transform Fault ◽  
Caribbean Plate ◽  
Basaltic Rocks ◽  
The North ◽  
Ophiolitic Mélange ◽  
Igneous Province ◽  
The Caribbean

AbstractThe geology of Puerto Rico is divided into three regions: the north, central and SW igneous provinces. Characterized by its Jurassic ophiolitic mélange basement, lithology of the SW Igneous Province (SIP) is not related to either of the other two provinces. The ophiolitic mélange is exposed in three peridotite belts: Monte del Estado, Rio Guanajibo and Sierra Bermeja. We present geochemical data to identify the tectonic setting of the SIP peridotite formation and its relation to the evolution of the Caribbean Plate. Comparisons of spinel Cr no. (13–21), Mg no. (63.3–69.6) and TiO2suggest an abyssal peridotite origin; however, only Sierra Bermeja presents high TiO2characteristics of a mid-ocean-ridge-basalt- (MORB-) like melt reaction. Temperatures determined with two-pyroxene geothermometers indicated a cold thermal regime ofc. 800–1050°C, with characteristics of large-offset transform fault abyssal peridotites. The geochemistry and Sr–Nd–Hf–Pb isotopic compositions of basalts within the mélange were also analysed. Las Palmas amphibolites exhibited normal-MORB-like rare earth element (REE) and trace-element patterns, whereas metabasalts and Lower Cajul basalts exhibited island-arc tholeiitic-like patterns. Highly radiogenic Sr isotopes (0.70339–0.70562) of the basalts suggest seawater alteration; however, Pb–Pb and Nd–Hf isotope correlations represent the primary compositions of a Pacific/Atlantic MORB source for the amphibolites, metabasalts and Lower Cajul basalts. We propose that the SIP ophiolitic mélange was formed along a large-offset transform fault, which initiated subduction and preserved both proto-Pacific and proto-Caribbean lithospheric mantle. Younger Upper Cajul basalts exhibited enriched-MORB-like geochemical and isotopic signatures, which can be attributed to a tectonized Caribbean ocean plateau.

Has the Tibetan plateau risen in the Early/Mid–Miocene? Constraints from plate–motion reconstructions and seismicity of the Indian Ocean lithosphere

2021 ◽  
Author(s):  
Giampiero Iaffaldano
Keyword(s):  
Indian Ocean ◽  
Tibetan Plateau ◽  
Tectonic Setting ◽  
Plate Motion ◽  
Tibet Plateau ◽  
Geochemical Data ◽  
The Tibetan Plateau ◽  
Plate Motions ◽  
The Indian Ocean ◽  
Ocean Lithosphere

Summary Magnetisation records and seismic stratigraphy of the Indian Ocean lithosphere indicate that the Early/Mid–Miocene onset of diffuse contractional deformation coincided with slowdowns of the Indian and Capricorn plate motions. At present day such deformation is evidenced by the seismicity of the Indian ocean floor. Deformation onset and past plate–motion slowdowns have been interpreted as consequences of a sudden uplift of the Tibetan plateau by 1 to 2 km, as this – following previous estimates – would generate a tectonically–significant force between 4 · 1012 and 8 · 1012 N/m. However, this view remains at odds with paleo–altimetry estimates from geological and geochemical data, which indicate no increase in plateau altitude throughout the Miocene. Here I use well–established models of viscous/brittle dynamics in inverse mode in order to constrain the amount of force that should be delivered by the Tibetan region to the Indian tectonic setting in order to explain the observations above. Results constrain such a force within the range from 4.3 · 1011 to 3.5 · 1012 N/m. By comparison with previous estimates of the force associated with topography increase, these analyses suggest that the Early/Mid–Miocene onset of contractional deformation and plate–motion slowdowns within the Indian Ocean require minimal uplift of the Tibet plateau of a few hundred meters. The seemingly–contradicting inferences on Early/Mid–Miocene Tibetan uplift that come from geophysical and geological/geochemical observations can be reconciled by noting that the required uplift amount is less than what is resolvable by modern paleo–altimetry techniques.

scholarly journals Petrochemistry and tectonic setting of Lower Cretaceous tholeiites from Franz Josef Land, U.S.S.R.

1988 ◽  
Vol 37 ◽  
pp. 31-49
Author(s):  
J. C. Bailey ◽  
C. K. Brooks
Keyword(s):  
Mantle Source ◽  
Lower Cretaceous ◽  
Tectonic Setting ◽  
Mineral Chemistry ◽  
Tholeiitic Basalt ◽  
Ocean Basin ◽  
The Arctic ◽  
Franz Josef Land ◽  
Depleted Mantle ◽  
The Arctic Ocean

The whole-rock geochemistry and mineral chemistry of six samples of Lower Cretaceous tholeiitic basalt from Franz Josef Land, U.S.S.R., have been studied. Geochemical criteria indicate that the basalts are initial rifting tholeiites characterised by low contents of Ti and other H-elements, suggesting derivation from a depleted mantle source. These tholeiites formed during a Lower Cretaceous rifting stage in the formation of the Arctic Ocean basin, most likely the opening of the Canada Basin.

Dike swarms on Seward Peninsula, Alaska, and their implications for the kinematics of Cretaceous extension in the Bering Strait region

2003 ◽  
Vol 40 (6) ◽  
pp. 865-886 ◽  
Author(s):  
Jeffrey M Amato ◽  
Elizabeth L Miller ◽  
James E Wright ◽  
William C McIntosh
Keyword(s):  
Late Cretaceous ◽  
Tectonic Setting ◽  
Ductile Deformation ◽  
Geochemical Data ◽  
Normal Faults ◽  
Bering Strait ◽  
Shear Sense ◽  
Seward Peninsula ◽  
Dike Swarms ◽  
Shear Sense Indicators

Late Cretaceous dike swarms on Seward Peninsula, northwestern Alaska, represent the youngest local manifestation of a ~115–75 Ma magmatic event in the Bering Strait region. Magmatism accompanied and followed high-grade metamorphism and ductile deformation. A Late Cretaceous extensional tectonic setting for the region is suggested by the thickness and seismic-reflection characteristics of the crust, regional basin development, formation of high-strain tectonites with subhorizontal foliations, bimodal magmatism, and dike swarms. The orientation of the dike swarms is used to address the kinematics of extension. A diabase dike swarm in the Kigluaik Mountains consists of dikes that strike northeast (040°) and dip steeply. Phenocrysts include plagioclase, clinopyroxene, orthopyroxene, and hornblende. Geochemical data indicate that SiO2 ranges from 48% to 56%, and K2O from 1.2% to 4.0%. The dikes are geochemically similar to the mafic to intermediate root of the 90 Ma Kigluaik pluton. Sr- and Nd-isotope data show that initial 87Sr/86Sr ranges from 0.7070 to 0.7077 and initial εNd ranges from –0.85 to –2.90. Field relations and 40Ar/39Ar geochronology bracket the dike ages between 90 and 84 Ma. Diabase dikes in the York Mountains are associated with normal faults that strike east–west to east-northeast. Dikes in the Bendeleben Mountains are both mafic and felsic, but their orientations are unknown. Alkalic dikes in the Darby Mountains strike 030°–050°, similar to those in the Kigluaik Mountains. Regional relationships including the orientation of dikes, normal faults, mineral stretching lineations, and other shear-sense indicators suggest that between 110 and 90 Ma extension on Seward Peninsula was generally oriented north–south to north-northwest–south-southeast.

Detrital zircon constraints on the tectonic evolution of the Gravina belt, southeastern Alaska

1998 ◽  
Vol 35 (3) ◽  
pp. 253-268 ◽  
Author(s):  
Paul A Kapp ◽  
George E Gehrels
Keyword(s):  
Detrital Zircon ◽  
Tectonic Setting ◽  
Volcanic Rocks ◽  
Upper Jurassic ◽  
Ocean Basin ◽  
Detrital Zircons ◽  
Plate Motion ◽  
The West ◽  
Gravina Belt ◽  
Cordilleran Margin

Upper Jurassic - Lower Cretaceous marine clastic strata and mafic to intermediate volcanic rocks of the Gravina belt are part of a complex suture zone separating the Alexander and Wrangellia terranes on the west from the Yukon-Tanana and Stikine terranes to the east. U-Pb ages have been determined on 118 single detrital zircon grains from Gravina strata in an effort to determine the tectonic setting of the Gravina belt and the paleoposition of outboard terranes prior to their Late Cretaceous juxtaposition against inboard terranes. Samples from five stratigraphic units yield ages of 105-120 (n = 5), 140-165 (n = 56), 310-380 (n = 17), 400-450 (n = 19), 520-560 (n = 5), 920-1310 (n = 5), and 1755-1955 Ma (n = 5). The 105-120 and 140-165 Ma grains were shed primarily from arc-related plutons that lie outboard of the Gravina belt. The lack of 120-140 Ma ages coincides with a lull in magmatism in the outboard arc and in the western United States, which suggests that Gravina strata accumulated during major changes in plate motion along the Cordilleran margin. The 400-560 Ma zircons were derived from rocks of the Alexander terrane which also lie to the west. In contrast, the 310-380 and >900 Ma grains were apparently shed from inboard regions. Likely sources include the Yukon-Tanana and Stikine terranes in the northern Cordillera and assemblages in the northern California region which contain igneous rocks and detrital zircons of the appropriate ages. Our data accordingly support models in which the Gravina basin formed in narrow rift or transtensional basins, whereas the outboard Alexander and Wrangellia terranes were located along the California - Oregon - Washington - British Columbia - Alaska margin. Our data are less supportive of models in which the Gravina strata and underlying Alexander and Wrangellia terranes were separated from western North America by a large ocean basin, or were located along the coast of Mexico.

A review of the tectonics of the northern Middle East region

1984 ◽  
Vol 121 (6) ◽  
pp. 577-587 ◽  
Author(s):  
P. E. R. Lovelock
Keyword(s):  
Late Cretaceous ◽  
Kinematic Model ◽  
Continental Collision ◽  
Dead Sea ◽  
Plate Motion ◽  
Arabian Plate ◽  
Southern Boundary ◽  
The North ◽  
The Dead ◽  
Two Stages

AbstractThe structure of the northern part of the Arabian platform is reviewed in the light of hitherto unpublished exploration data and the presently accepted kinematic model of plate motion in the region. The Palmyra and Sinjar zones share a common history of development involving two stages of rifting, one in the Triassic–Jurassic and the other during late Cretaceous to early Tertiary times. Deformation of the Palmyra zone during the Mio-Pliocene is attributed to north–south compression on the eastern block of the Dead Sea transcurrent system which occurred after continental collision in the north in southeast Turkey. The asymmetry of the Palmyra zone is believed to result from northward underthrusting along the southern boundary facilitated by the presence of shallow Triassic evaporites. An important NW-SE cross-plate shear zone has been identified, which can be traced for 600 km and which controls the course of the River Euphrates over long distances in Syria and Iraq. Transcurrent motion along this zone resulted in the formation of narrow grabens during the late Cretaceous which were compressed during the Mio-Pliocene. To a large extent, present day structures in the region result from compressional reactivation of old lineaments within the Arabian plate by the transcurrent motion of the Dead Sea fault zone and subsequent continental collision.

Mesozoic Tectonic Setting of SE Sundaland After Magmatism and Suture Evidences in JS-1 Ridge Area

2021 ◽  
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Tectonic Setting ◽  
Plate Boundary ◽  
Early Jurassic ◽  
The South ◽  
Magmatic Arc ◽  
Plate Convergence ◽  
Ridge Area ◽  
Cretaceous Subduction

Mesozoic plate convergence in SE Sundaland has been a source of debate for decades. A determination of plate convergence boundaries and timing have been explained in many publications, but not all boundaries were associated with magmatism. Through integration of both plate configurations and magmatic deposits, the basement can be accurately characterized over time and areal extents. This paper will discuss Cretaceous subductions and magmatic arc trends in SE Sundaland area with additional evidence found in JS-1 Ridge. At least three subduction trends are captured during the Mesozoic in the study area: 1) Early Jurassic – Early Cretaceous trend of Meratus, 2) Early Cretaceous trend of Bantimala and 3) Late Cretaceous trend in the southernmost study area. The Early Jurassic – Early Cretaceous subduction occurred along the South and East boundary of Sundaland (SW Borneo terrane) and passes through the Meratus area. The Early Cretaceous subduction occurred along South and East boundary of Sundaland (SW Borneo and Paternoster terranes) and pass through the Bantimala area. The Late Cretaceous subduction occurred along South and East boundary of Sundaland (SW Borneo, Paternoster and SE Java – South Sulawesi terranes), but is slightly shifted to the South approaching the Oligocene – Recent subduction zone. Magmatic arc trends can also be generally grouped into three periods, with each period corresponds to the subduction processes at the time. The first magmatic arc (Early Jurassic – Early Cretaceous) is present in core of SW Borneo terrane and partly produces the Schwaner Magmatism. The second Cretaceous magmatic arc (Early Cretaceous) trend is present in the SW Borneo terrane but is slightly shifted southeastward It is responsible for magmatism in North Java offshore, northern JS-1 Ridge and Meratus areas. The third magmatic arc trend is formed by Late Cretaceous volcanic rocks in Luk Ulo, the southern JS-1 Ridge and the eastern Makassar Strait areas. These all occur during the same time within the Cretaceous magmatic arc. Though a mélange rock sample has not been found in JS-1 Ridge area, there is evidence of an accretionary prism in the area as evidenced by the geometry observed on a new 3D seismic dataset. Based on the structural trend of Meratus (NNE-SSW) coupled with the regional plate boundary understanding, this suggests that both Meratus & JS-1 Ridge are part of the same suture zone between SW Borneo and Paternoster terranes. The gradual age transition observed in the JS-1 Ridge area suggests a southward shift of the magmatic arc during Early Cretaceous to Late Cretaceous times.

scholarly journals Seismostratigraphic Interpretation of Upper Cretaceous Reservoir from the Carpathian Foreland, Southern Poland

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7776
Author(s):  
Andrzej Urbaniec ◽  
Anna Łaba-Biel ◽  
Anna Kwietniak ◽  
Imoleayo Fashagba
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
Tectonic Setting ◽  
Small Scale ◽  
Reservoir Properties ◽  
Southern Poland ◽  
Seismic Sequence Stratigraphy ◽  
First Results ◽  
Depositional Architecture ◽  
The Impact

The Upper Cretaceous complex in the central part of the Carpathian Foreland (southern Poland) is relatively poorly recognized and described. Its formations can be classified as unconventional reservoir due to poor reservoir properties as well as a low recovery factor. The main aim of the article is to expand knowledge with conclusions resulting from the analysis of the latest seismic data with the application of seismic sequence stratigraphy. Moreover, the seismic attributes analysis was utilized. The depositional architecture recognition based on both chronostratigraphic horizons and Wheeler diagram interpretations was of paramount importance. A further result was the possibility of using the chronostratigraphic image for tectonostratigraphic interpretation. Two distinguished tectonostratigraphic units corresponding to megasequences were recognized. A tectonic setting of the analyzed interval is associated with global processes noticed by other authors in other parts of the central European Late Cretaceous basin, but also locally accompanied by evidence of small-scale tectonics. This study fills the gap on the issue of paleogeography in the Late Cretaceous sedimentary basin of the Carpathian Foreland. It presents the first results of detailed reconstruction of the basin paleogeography and an attempt to determine the impact of both eustatic and tectonic factors on sedimentation processes.

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