scholarly journals Evolução Tectono-Estratigráfica e Paleoclimática da Formação Maricá (Escudo Sul-Rio-Grandense, Brasil): um Exercício de Geologia Histórica e Análise Integrada de uma Bacia Sedimentar Neoproterozóica

2007 ◽  
Vol 34 (2) ◽  
pp. 57 ◽  
Author(s):  
ANDRÉ DE BORBA ◽  
ANDERSON MARASCHIN ◽  
ANA MARIA MIZUSAKI
Keyword(s):  
Foreland Basin ◽  
Global Scale ◽  
Source Rocks ◽  
Integrated Analysis ◽  
Santa Barbara ◽  
Volcanic Event ◽  
Nd Isotope ◽  
Shrimp Geochronology ◽  
Step Heating ◽  
Depositional Evolution

Significant improvement in the knowledge concerning the Neoproterozoic Maricá Formation of the Sul-riograndense Shield, southern Brazil, was obtained in the latest years. This contribution synthesizes recent data obtained though an integrated analysis of the lowermost unit of the “Camaquã Basin”. Stratigraphic and paleocurrent analyses, petrography, Sr and Nd isotope geology, U-Pb SHRIMP geochronology and Ar-Ar dating were applied to the sedimentary and volcanogenic record of the Maricá Formation in order to better constrain its depositional evolution. The Maricá Formation was deposited within a coastal to shallow marine setting, its detrital load being derived from the weathering of granite-gneissic, paleoproterozoic (1.76 to 2.37 Ga) source rocks, possibly located in the western La Plata craton. A syn-depositional, partially explosive, volcanic event was recognized and dated by U-Pb SHRIMP at 630.2 ± 3.4 Ma, positioning the inception of the “Camaquã Basin” at the end of the Cryogenian. Thus, the deposition of the Maricá Formation post-dates the global-scale Marinoan glaciation (660-635 Ma), possibly recording greenhouse paleoclimatic conditions. Field, petrographic and isotopic evidence supports this interpretation. The evolution of the Maricá Formation started during the collisional climax of the Brasiliano II orogenic system (Dom Feliciano orogen), thus the analyzed sedimentation could represent the infilling of a foreland basin. It is possible that correlative portions of the foreland system may be preserved in other sedimentary or metamorphic successions of the Mantiqueira Province, such as the Fuente del Puma (Lavalleja), Porongos, Brusque, Abapã (Itaiacoca), Cerro da Árvore and Passo da Capela units. The 507.3 ± 1.8 and 506.7 ± 1.4 Ma Ar-Ar step-heating ages obtained in K-feldspars from volcanogenic samples of the Maricá Formation are most likely associated with uplift and cooling below ca. 200ºC, possibly during the inception of the rift where the Camaquã Group (Santa Bárbara and Guaritas formations) accumulated.

The Yenisei-Khatanga Composite Tectono-Sedimentary Element, Northern Siberia

2021 ◽  
pp. M57-2021-15
Author(s):  
E. V. Deev ◽  
G. G. Shemin ◽  
V. A. Vernikovsky ◽  
O. I. Bostrikov ◽  
P. A. Glazyrin ◽  
...  
Keyword(s):  
Siberian Craton ◽  
Middle Triassic ◽  
Foreland Basin ◽  
Early Carboniferous ◽  
Source Rocks ◽  
Total Thickness ◽  
Petroleum Potential ◽  
Early Paleocene ◽  
Middle Carboniferous ◽  
Severnaya Zemlya

AbstractThe Yenisei-Khatanga Composite Tectono-Sedimentary Element (YKh CTSE) is located between the Siberian Craton and the Taimyr-Severnaya Zemlya fold-and-thrust belt. The total thickness of the Mesoproterozoic-Cenozoic sediments of YKh CTSE reaches 20 to 25 km. They are divided into four tectono-sedimentary elements (TSE): (i) Mesoproterozoic-early Carboniferous Siberian Craton continental margin, (ii) middle Carboniferous-Middle Triassic syn-orogenic Taimyr foreland basin, (iii) late Permian-Early Triassic syn-rift, and (iv) Triassic-Early Paleocene post-rift. The last one is the most important in terms of its petroleum potential and is the most drilled part of the CTSE. Its thickness accounts for half of the total thickness of YKh CTSE. The margins of the post-rift TSE and the inner system of inversion swells and adjacent troughs and depressions were shaped by three tectonic events: (i) middle Carboniferous-Middle Triassic Taimyr orogeny, (ii) Late Jurassic-Early Cretaceous Verkhoyansk orogeny, (iii) Late Cenozoic uplift. These processes led to more intense migration of hydrocarbons, the trap formation and their infill with hydrocarbons. Triassic, Jurassic, and Lower Cretaceous source rocks are mostly gas-prone, and among 20 discovered fields in Jurassic and Cretaceous plays, 17 are gas or mixed-type fields.

Nd and Pb isotope mapping of crustal domains within the Makkovik Province, Labrador

2018 ◽  
Vol 156 (5) ◽  
pp. 833-848 ◽  
Author(s):  
R. M. MOUMBLOW ◽  
G. A. ARCURI ◽  
A. P. DICKIN ◽  
C. F. GOWER
Keyword(s):  
Early Stage ◽  
Foreland Basin ◽  
Mobile Belt ◽  
South American ◽  
Pb Isotope ◽  
Volcanic Arc ◽  
Nd Isotope ◽  
North American Cordillera ◽  
Tectonic Model ◽  
Isotope Data

AbstractThe Makkovik Province of eastern Labrador represents part of an accretionary orogen active during an early stage in the development of the Palaeoproterozoic southern Laurentian continental margin. New Nd isotope data for the eastern Makkovik Province suggest that accreted juvenile Makkovik crust was generated in the Cape Harrison domain during a single crust-forming event at c. 2.0 Ga. Pb isotope data support this model, and show a strong similarity to radiogenic crustal signatures in the juvenile Palaeoproterozoic crust of the Ketilidian mobile belt of southern Greenland. As previously proposed, an arc accretion event at c. 1.9 Ga triggered subduction-zone reversal and the development of an ensialic arc on the composite margin. After the subduction flip, a temporary release of compressive stress at c. 1.87 Ga led to the development of a retro-arc foreland basin on the downloaded Archean continental edge, forming the Aillik Group. Unlike previous models, a second arc is not envisaged. Instead, a compressive regime at c. 1.82 Ga is attributed to continued ensialic arc plutonism on the existing margin. The tectonic model for the Makkovikian orogeny proposed here is similar to that for the Ketilidian orogeny. Major- and trace-element analyses suggest that much of the magmatism in the Makkovik orogen results from post-accretionary ensialic arc activity, and that few vestiges remain of the original accreted volcanic arc. This pattern of arc accretion and intense post-accretion reworking is common to many accretionary orogens, such as the South American Andes and North American Cordillera.

Anabar-Lena Composite Tectono-Sedimentary Element, Northern East Siberia

2021 ◽  
pp. M57-2021-29
Author(s):  
A.K. Khudoley ◽  
S.V. Frolov ◽  
G.G. Akhmanov ◽  
E.A. Bakay ◽  
S.S. Drachev ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Oil And Gas ◽  
Foreland Basin ◽  
Early Carboniferous ◽  
Passive Margin ◽  
Source Rocks ◽  
East Siberia ◽  
Lena River ◽  
Petroleum Systems ◽  
Intracratonic Basin

AbstractAnabar-Lena Composite Tectono-Sedimentary Element (AL CTSE) is located in the northern East Siberia extending for c. 700 km along the Laptev Sea coast between the Khatanga Bay and Lena River delta. AL CTSE consists of rocks from Mesoproterozoic to Late Cretaceous in age with total thickness reaching 14 km. It evolved through the following tectonic settings: (1) Meso-Early Neoproterozoic intracratonic basin, (2) Ediacaran - Early Devonian passive margin, (3) Middle Devonian - Early Carboniferous rift, (4) late Early Carboniferous - latest Jurassic passive margin, (5) Permian foreland basin, (6) Triassic to Jurassic continental platform basin and (7) latest Jurassic - earliest Late Cretaceous foreland basin. Proterozoic and lower-middle Paleozoic successions are composed mainly by carbonate rocks while siliciclastic rocks dominate upper Paleozoic and Mesozoic sections. Several petroleum systems are assumed in the AL CTSE. Permian source rocks and Triassic sandstone reservoirs are the most important play elements. Presence of several mature source rock units and abundant oil- and gas-shows (both in wells and in outcrops), including a giant Olenek Bitumen Field, suggest that further exploration in this area may result in economic discoveries.

Late Permian mafic rocks identified within the Doba basin of southern Chad and their relationship to the boundary of the Saharan Metacraton

2015 ◽  
Vol 152 (6) ◽  
pp. 1073-1084 ◽  
Author(s):  
J. GREGORY SHELLNUTT ◽  
TUNG-YI LEE ◽  
CHIH-CHENG YANG ◽  
SHIN-TAI HU ◽  
JONG-CHANG WU ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Central Africa ◽  
Late Permian ◽  
Southern Boundary ◽  
North Central ◽  
Nd Isotope ◽  
Mantle Sources ◽  
Basaltic Melt ◽  
Step Heating ◽  
Trace Elemental

AbstractThe Doba gabbro was collected from an exploration well through the Cretaceous Doba basin of southern Chad. The gabbro is composed mostly of plagioclase, clinopyroxene and Fe–Ti oxide minerals and displays cumulus mineral textures. Whole-rock40Ar–39Ar step-heating geochronology yielded a Late Permian plateau age of 257 ± 1 Ma. The major and trace elemental geochemistry shows that the gabbro is tholeiitic in composition and has trace element ratios (i.e. La/YbN> 7; Sm/YbPM> 3.4; Nb/Y > 1; Zr/Y > 5) indicative of a basaltic melt derived from a garnet-bearing mantle source. The moderately enriched Sr–Nd isotopes (i.e. ISr= 0.70495 to 0.70839; ɛNd(T)= −1.0 to −1.3) fall within the mantle array (i.e. OIB-like) and are similar to other Late Permian plutonic rocks of North-Central Africa (i.e. ISr= 0.7040 to 0.7070). The enriched isotopic composition of the Doba gabbro contrasts with the more depleted compositions of the spatially associated Neoproterozoic post-Pan-African within-plate granites. The contrasting Nd isotope composition between the older within-plate granites and the younger Doba gabbro indicates that different mantle sources produced the rocks and thus may mark the southern boundary of the Saharan Metacraton.

Age of source rocks of the Late Precambrian metaterrigenous sediments of the South Ulutau mountains, Central Kazakhstan: U-Pb and Sm-Nd isotope data

2015 ◽  
Vol 463 (1) ◽  
pp. 715-718 ◽  
Author(s):  
N. V. Dmitriev ◽  
E. F. Letnikova ◽  
K. E. Degtyarev ◽  
A. A. Trertyakov ◽  
H. Geng
Keyword(s):  
Source Rocks ◽  
The South ◽  
Nd Isotope ◽  
Late Precambrian ◽  
Isotope Data

scholarly journals The Natih Petroleum System of North Oman

GeoArabia ◽  
1999 ◽  
Vol 4 (2) ◽  
pp. 157-180 ◽  
Author(s):  
Jos M.J. Terken
Keyword(s):  
Foreland Basin ◽  
Petroleum System ◽  
Source Rocks ◽  
Trapping Efficiency ◽  
Structural Deformation ◽  
Hydrocarbon Potential ◽  
Lateral Migration ◽  
Efficient System ◽  
Giant Fields ◽  
And Migration

ABSTRACT The Cretaceous Natih petroleum system is one of the smaller petroleum systems in Oman, measuring only some 20,000 square kilometers in areal extent. Resource volumes of oil initially in-place, however, are significant and amount to 1.3x109 cubic meters (equivalent to 8.2 billion barrels). Most of the recoverable oil is concentrated in two giant fields that were discovered in the early 1960s. Since that prolific time no new major discoveries have been made, except some marginally economic accumulations in the early 1980s. To evaluate the remaining hydrocarbon potential of the system, the oil kitchen was mapped and its generation and migration histories modeled and integrated with the regional setting to outline the geographical and stratigraphical extent of the petroleum system. The volume of liquid hydrocarbons generated by Natih source rocks was calculated and compared to the estimated oil-in-place to determine the generation-trapping efficiency of the petroleum system. Some 100x109 cubic meters of source rock is currently mature and produced a cumulative volume of 14x109 cubic meters (88 billion barrels) oil. Of this volume 9% has actually been discovered and 0.25x109 cubic meters (1.57 billion barrels) are currently booked as recoverable reserves, equivalent to 1.8% of the total generated volume. Both percentages classify the Natih petroleum system as the most efficient system in Oman. This extreme efficiency results from several factors, such as: (1) modest structural deformation in the foreland basin, which permits lateral migration to remain the dominant style; (2) abundant and uninterrupted access to oil charge from an active kitchen in the foreland basin; and (3) excellent intra-formational source rocks, which is retained by thick Fiqa shales. Most structural prospects have been tested in four decades of exploration. The remaining hydrocarbon potential is anticipated to exist mainly in stratigraphic traps in Fiqa turbidites in the foreland basin, and truncation traps across the northern flank of the peripheral bulge.

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