SEISMIC FACIES OF SHELFEDGE DEPOSITS, U.S. PACIFIC CONTINENTAL MARGIN

1983 ◽  
pp. 299-313 ◽  
Author(s):  
MICHAEL E. FIELD ◽  
PAUL R. CARLSON ◽  
ROBERT K. HALL
Keyword(s):  
Continental Margin ◽  
Seismic Facies

Seismic stratigraphy and tectono-sedimentary framework of the Pliocene to recent Taixinan foreland basin in the northeastern continental margin, South China Sea

2016 ◽  
Vol 4 (3) ◽  
pp. SP21-SP32 ◽  
Author(s):  
Shaoru Yin ◽  
Guangfa Zhong ◽  
Yiqun Guo ◽  
Liaoliang Wang
Keyword(s):  
South China Sea ◽  
Continental Margin ◽  
South China ◽  
Late Quaternary ◽  
Foreland Basin ◽  
Transport Processes ◽  
Passive Margin ◽  
Seismic Facies ◽  
China Sea ◽  
Taixinan Basin

The Pliocene to recent Taixinan basin is a unique foreland basin built on the northeastern part of the northern passive margin of the South China Sea (SCS). We have used multichannel seismic profiles tied to well controls from ODP Leg 184 to investigate the tectonic and sedimentary characteristics of the foreland basin. We defined three seismic sequences, dated respectively to the Pliocene (5.33–2.5 Ma), early Quaternary (2.5–1.0 Ma), and late Quaternary (1.0 Ma–present). They represent three stages of evolution of the foreland basin. We have recognized seven types of seismic facies, which are parallel-to-subparallel, progradational, fill-type, divergent mounded, wavy, lenticular, and chaotic facies, and are interpreted as hemipelagic deposits, deltas, submarine canyon fills, levees, sediment waves, submarine fans, and mass transport deposits, respectively. Seismic facies analysis indicates that sedimentation within the foreland basin has been dominated by turbidity currents and the other gravity transport processes. Tectonically, the foreland basin consists of three structural zones: an eastern wedge-top, a central foredeep, and a western forebulge zones. Different from a typical foreland basin, however, the basin extends in the northeast–southwest direction, which is oblique to the north–south-striking Taiwan orogenic zone, but parallel to the northern SCS passive margin, where the basin is hosted, suggesting that the foreland basin is significantly influenced by the development of the passive margin. In addition, the basin displays a distinctive inverted-triangle-shaped downstream-converging sediment dispersal system instead of ideal transverse or longitudinal drainage systems common in a typical foreland basin. We have suggested that the Pliocene to recent Taixinan basin is an atypical foreland basin, which was formed as a flexural response of tectonic loading by the Taiwan orogenic wedge, but strongly affected by its passive continental margin background.

Subsurface basement, structure, stratigraphy, and timing of regional tectonic events affecting the Guajira margin of northern Colombia

2020 ◽  
Vol 8 (4) ◽  
pp. ST69-ST105
Author(s):  
Eleine Vence ◽  
Paul Mann
Keyword(s):  
Continental Margin ◽  
Late Eocene ◽  
Seismic Facies ◽  
Tectonic Events ◽  
Regional Tectonic ◽  
Basin Formation ◽  
The Caribbean ◽  
Basement High ◽  
Marine Seismic ◽  
Sea Fan

We have combined previous data from Mesozoic-Cenozoic outcrops in the Guajira Peninsula of northern Colombia with regional gravity, bathymetric, and seismic interpretations to demonstrate the existence of a 280 km long western extension of the Great Arc of the Caribbean (GAC) along the continental margin of Colombia. Seismic data reveal an 80–100 km wide domal-shaped basement high that exhibits internal chaotic seismic facies. This elongate and domal-shaped structure extends 1800 km from the Aves Ridge in the Caribbean Sea to the study area in offshore Colombia. The western extension of the GAC in Colombia and western Venezuela is buried by 700–3000 m of continental margin sedimentary rocks as a result of the GAC colliding earlier with the Colombian margin (Cretaceous-early Paleogene collision) than its subaerially exposed eastern extension along the Leeward Antilles ridge (late Paleogene-Neogene). Our compilation of geologic information from the entire GAC reveals that GAC magmatism occurred from 128 to 74 Ma with magmatism ages progressively younger toward the east. Six upper Eocene to recent marine seismic sequences overlying the domal basement high of the GAC have been mapped by our analysis of 2400 km of seismic lines and 12 well logs. Based on subsurface mapping correlated with well-log information and onland geology in the Guajira Peninsula, these six sequences record four major deformational events: (1) late Eocene rifting in an east–west direction produced half-grabens in the northern part of the area, (2) Oligocene transtension in the southern part of the area expressed by right-lateral Oligocene strike-slip faulting and extensional basin formation, (3) early-middle Miocene transtension, and (4) late Miocene-early Pliocene Andean uplift accompanied by rapid erosion and clastic infilling of offshore basins by the Magdalena delta and deep-sea fan. The significance of this basin framework is discussed for known and inferred hydrocarbon systems.

scholarly journals PALEOCENE SEISMIC FACIES IN THE CONTINENTAL MARGIN OF URUGUAY (SOUTH AMERICA)

2019 ◽  
Vol 4 (3) ◽  
pp. 263-275 ◽  
Author(s):  
Matías Soto ◽  
Belén Viera ◽  
Ethel Morales ◽  
Bruno Conti ◽  
Francisco Javier Hernández-Molina
Keyword(s):  
South America ◽  
Continental Margin ◽  
Source Rocks ◽  
Seismic Facies ◽  
Bottom Currents ◽  
Different Characteristics

In this contribution seismic facies of the Paleocene sequence are characterized in offshore basins of Uruguay through the study of a 2D seismic database. Seven seismic horizons were identified, limiting six sedimentary intervals with different characteristics. Hence, the complexity of the Paleocene sequence is greater than suggested by other studies. Seismic facies located in the basis of the sequence can be interpreted as sandy deposits related to the action of both turbidity and bottom currents. The identification of these deposits agrees with the expected Cretaceous source rocks, in addition to the importance of the overlying Paleocene shales as a regional seal. The results of this work open interesting exploratory perspectives in the continental margin of Uruguay. FACIES SÍSMICAS DO PALEOCENE NA MARGEM CONTINENTAL DO URUGUAI (AMÉRICA DO SUL) ResumoNesta contribuição, as fácies sísmicas da sequência do Paleoceno são caracterizadas em bacias offshore do Uruguai através do estudo de uma base de dados sísmica 2D. Foram identificados sete horizontes sísmicos, limitando seis intervalos sedimentares com diferentes características. Neste estudo verifica-se que a complexidade da seqüência do Paleoceno é maior do que a sugerida por outros estudos. A fácies sísmicas localizadas na base da sequência podem ser interpretadas como sendo depósitos arenosos resultantes da ação de correntes de turbidez e de fundo. Estes depósitos correspondem a rochas-fonte cretáceas, estando cobertas regionalmente por importantes rochas selantes correspondentes a folhelhos do Paleoceno. Os resultados deste trabalho abrem interessantes perspectivas exploratórias na margem continental do Uruguai.Palavras-chave: Paleoceno. Facies Sísmicas. Margem Continental do Uruguai.

Late Quaternary Tectonics vs Sedimentation history of the offshore Termini in a seismically active segment of the Northern Sicily Continental margin (Southern Tyrrhenian Sea)

2020 ◽  
Author(s):  
Elisabetta Zizzo ◽  
Attilio Sulli ◽  
Daniele Spatola ◽  
Christian Gorini ◽  
Maurizio Gasparo Morticelli
Keyword(s):  
High Resolution ◽  
Continental Margin ◽  
Late Quaternary ◽  
Mass Movement ◽  
Strike Slip ◽  
Seismic Facies ◽  
Tyrrhenian Sea ◽  
Depositional Sequence ◽  
Coastal Belt ◽  
Southern Tyrrhenian Sea

<p>We investigate the tectonically active Northern Sicily Continental margin focusing on the neotectonics affecting the Offshore of Termini (Southern Tyrrhenian Sea) by using high-resolution seismic and multibeam data. The sedimentary succession along the North Sicilian Continental Margin (NSCM) represents the marine prolongation of those outcropping along the Northern Sicily coastal belt. The NSCM has been originated as a consequence of a complex interaction of compressional events, crustal thinning, and strike-slip faulting. E–W, NW–SE, and NE–SW trending, both extensional and compressional faults, with a local strike-slip component, exerted control on the morphology of the present-day shelf and coastal areas during the Pleistocene. During the Quaternary,  the tectonic as well as depositional events have strongly shaped the margin forming the actual complex geomorphic setting of the margin. We present the main results of a high resolution survey that allow to identify several features (e.g. Mass Transport Deposits and pockmarks) linked to gravitational mass movement and fluids escape processes strongly controlled by the tectonics affecting the NSCM. All over the study area, we mapped inside the Late Quaternary depositional sequence repeated and variously distributed MTDs, characterised by transparent/chaotic seismic facies, interbedded to hemipelagic deposits, with seismic facies showing subparallel seismic reflectors of the transgressive and high stand systems tracts. We infer that this MTDs have been seismically induced by earthquakes.  We estimate the recurrence times of earthquakes, by using an elaborate age-model that considers a constant sedimentation rate for the last 11.5 My, between 680 and 2200 years.</p>

scholarly journals SEISMIC STRATIGRAPHY OF THE EOCENE–LOWER OLIGOCENE IN THE URUGUAYAN CONTINENTAL MARGIN / ESTRATIGRAFIA SÍSMICA DO EOCENO AO OLIGOCENO INFERIOR NA MARGEM CONTINENTAL URUGUAIA

2018 ◽  
Vol 3 (4) ◽  
pp. 290-306 ◽  
Author(s):  
Belén Viera Honegger ◽  
Ethel Morales ◽  
Matias Soto ◽  
Bruno Conti
Keyword(s):  
Continental Margin ◽  
Sedimentary Basins ◽  
Seismic Facies ◽  
Depositional Sequences ◽  
Normal Regression ◽  
Depositional Systems ◽  
Seismic Sections ◽  
Pelotas Basin ◽  
Definition Of ◽  
Stacking Patterns

The Uruguayan continental margin was generated following the fragmentation of the Gondwana supercontinent and the subsequent opening of South Atlantic Ocean. It constitutes an extensive sedimentation area in which three sedimentary basins can be found: the Punta del Este Basin, the southernmost portion of the Pelotas Basin, and the poorly defined Oriental del Plata Basin. The aim of this work was the identification and characterization of the different seismic units (seismic facies, systems tracts, depositional sequences) for the sedimentary interval assigned to the Eocene in the Uruguayan continental margin. Sequence stratigraphy was used as a basin analysis method for this purpose, using a database that consisted of approximately 10,000 kilometers of 2D seismic sections, acquired in exploratory surveys in 2007 and 2008. The workflow included the recognition of stacking patterns and/or stratal terminations, the definition of genetically significant stratigraphic surfaces and, based on these, the identification of systems tracts and depositional sequences. Three depositional sequences were identified in the studied sedimentary interval. The basal sequence is composed of four depositional systems tracts, including falling stage, normal regression (lowstand and highstand) and transgressive deposits. The intermediate sequence only preserves lowstand normal regression deposits. The third sequence is composed by three depositional systems tracts, including lowstand, transgressive and falling stage deposits. ResumoA margem continental uruguaia foi gerada após a fragmentação do supercontinente Gondwana e a subsequente abertura do Oceano Atlântico Sul. Constitui uma extensa área de sedimentação em três bacias sedimentares: a bacia de Punta del Este, a porção mais ao sul da Bacia de Pelotas e a Bacia Oriental del Plata, pouco definida. O objetivo deste trabalho foi a identificação e caracterização das diferentes unidades sísmicas (fácies sísmicas, tratos de sistemas, seqüências deposicionais) para o intervalo sedimentar atribuído ao Eoceno na margem continental uruguaia. Com este objetivo, utilizou-se a estratigrafia de seqüencias como método de análise de bacias, tendo-se utilizado um banco de dados constituído por aproximadamente 10.000 km de seções sísmicas 2D, adquiridas em pesquisas exploratórias em 2007 e 2008. O trabalho incluiu o reconhecimento de padrões de empilhamento e/ou terminações estratais, a definição de superfícies estratigráficas geneticamente significativas, tendo-se efetuado com base nelas, a identificação de tratos de sistemas e seqüências deposicionais. Três seqüências deposicionais foram identificadas no intervalo sedimentar estudado. A seqüência basal é composta por quatro tratos de sistemas deposicionais, incluindo a fase de abaixamento do nível do mar, a regressão normal e depósitos transgressivos. A sequência intermediária apenas preserva os depósitos de regressão normais de nível de mar baixo. A terceira seqüência é composta por três tratos de sistemas deposicionais, incluindo depósitos de nível de mar baixo, transgressivos e de abaixamento do nível do mar.

scholarly journals A NEW GEOLOGICAL MODEL BASED ON A SEISMIC-STRATIGRAPHIC ANALYSIS OF THE EASTERN INHAMBÚ OIL FIELD, ONSHORE ESPÍRITO SANTO BASIN, BRAZIL

2018 ◽  
Vol 36 (3) ◽  
pp. 1
Author(s):  
Igor de A. Neves ◽  
Wagner M. Lupinacci ◽  
Cleverson G. Silva
Keyword(s):  
Continental Margin ◽  
Oil Production ◽  
Oil Field ◽  
Seismic Facies ◽  
Geological Model ◽  
Espírito Santo ◽  
Stratigraphic Analysis ◽  
Geophysical Logs ◽  
Espirito Santo ◽  
Regressive Events

ABSTRACT. The Espírito Santo onshore basin is an important hydrocarbon province on the eastern Brazilian continental margin that accounts for almost 9% of Brazil’s onshore oil production. This study aims to understand the stratigraphy and geologic evolution of the eastern Inhambú onshore oil field from the post-rift section (Cricaré Formation, Mucuri Member) to the drift section (Rio Doce Formation). We interpret the main stratigraphic surfaces and seismic facies from the basement to the upper pre-Eocene unconformity to build a chronostratigraphic chart and identify the main transgressive and regressive events. Lithological and geophysical logs from new wells allowed the identification of six 3rd -order cycles, including four regressive and two transgressive events. Based on these results, a new conceptual geological model for the eastern Inhambú Oil Field is proposed. Keywords: Chronostratigraphic Chart, Seismic Facies, Canyon Fazenda Cedro, Espírito Santo Basin.RESUMO. A bacia terrestre do Espírito Santo é uma importante província produtora de hidrocarbonetos na margem leste do Brasil, respondendo por quase 9% da produção brasileira de petróleo em terra. O presente trabalho teve como objetivo entender a estratigrafia e a história evolutiva, desde a seção pós-rifte (Formação Cricaré, Membro Mucuri) até a seção drifte (Formação Rio Doce), de uma área a leste ao Campo de Inhambú e assim propor um novo modelo geológico para a área. Neste estudo, foram interpretadas as principais superfícies estratigráficas e identificadas as principais sismofácies desde o embasamento até a discordância do pré-Eoceno Superior, criando-se uma carta cronoestratigráfica de eventos. A interpretação de dados litológicos e geofísicos de poços permitiu o reconhecimento de seis ciclos de 3a ordem, onde foi possível identificar quatro eventos com caráter regressivo, e dois de caráter transgressivo. Como resultado final foi criado um novo modelo geológico conceitual para a área leste do campo petrolífero de Inhambú.Palavras-chave: Carta Cronoestratigráfica de Eventos, Sismofácies, Cânion de Fazenda Cedro, Bacia do Espírito Santo.

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