New sequence stratigraphic framework on a ‘passive’ margin: Implications for post-breakup depositional environment and onset of glaciomarine conditions in Northeast Greenland

2020 ◽  
pp. jgs2020-128
Author(s):  
Thomas G. Petersen
Keyword(s):  
Late Eocene ◽  
Passive Margin ◽  
Tectonic Activity ◽  
Sequence Stratigraphic ◽  
Submarine Fans ◽  
The North ◽  
Tectonic Forces ◽  
Stratigraphic Evolution ◽  
Erosional Event ◽  
The Impact

Detailed sequence stratigraphic frameworks have been produced for most of the Cenozoic deposits around the North Atlantic and Greenland Sea. However, the sequence stratigraphic evolution of the Northeast Greenland shelf, a significant part of the Atlantic Ocean margin, has so far never been interpreted. This study provides for the first time, a detailed sequence stratigraphic interpretation of the Northeast Greenland shelf since the late Eocene. Tectonic evolution, eustatic sea level change and the impact of glaciations are integrated into a consistent geological history. Based on the identification of pronounced unconformities and their correlative conformities, 10 stratigraphic sequences are identified. The onset of deposition is defined by a pronounced erosional event, where late Palaeocene tectonic activity caused mass wasting of the uplifted footwall of the Danmarkshavn Ridge along ca. 200 km section of the ridge. During the mid Miocene, a second pronounced unconformity developed across the margin, which caused forced regressive submarine fans to prograde across the margin. The following tectonic quiet period is overlain by glaciomarine deposits, with evidence of ice deformation reaching the present day shelf break. Finally, unknown superregional plate tectonic forces are suggested as a driver of sequence formation based on correlation with the Canadian Arctic.

THE MIDDLE CRETACEOUS TO RECENT SEQUENCE STRATIGRAPHIC EVOLUTION OF THE EXMOUTH-BARROW MARGIN, WESTERN AUSTRALIA

2001 ◽  
Vol 41 (1) ◽  
pp. 381 ◽  
Author(s):  
H.C. Young ◽  
N.M. Lemon ◽  
J.N.F Hull
Keyword(s):  
Passive Margin ◽  
Outer Shelf ◽  
Early Miocene ◽  
Early Pliocene ◽  
North West ◽  
Sequence Stratigraphic ◽  
The North ◽  
Stratigraphic Model ◽  
Sequence Boundaries ◽  
Stratigraphic Evolution

Five supersequences have been revealed by a regional sequence stratigraphic study conducted in the Albian (109 Ma) to Recent section of the Exmouth-Barrow passive margin. The interpretation utilises a new sequence stratigraphic model developed for mixed siliciclasticcarbonate lithofacies. A high degree of resolution is brought to the study by identification of 37 regional sequence boundaries controlled by biostratigraphic, wireline and seismic data. Ditch cutting analysis, integrated into the new chronostratigraphic framework, provided detailed lithofacies maps.The five supersequences, named the Gallic, Senonian, Palaeogene, Middle Neogene and Pliocene, are based upon regional lowstand, transgressive and highstand phases. The Gallic Supersequence (late Tithonian–latest Cenomanian) represents a marine incursion of siliciclastic sediments coincident with the rifting and accelerated movement of India away from Australia. A Senonian Supersequence (latest Cenomanian–middle Maastrichtian) truncates the previous supersequence with incised canyons developed on the outer shelf. The evolution of the Senonian section corresponds to the Australian separation from Antarctica and the first appearance of carbonates.The Palaeogene Supersequence (middle Maastrichtian– late Early Miocene) dominates much of the Tertiary and is identified by a basinward shift of facies following a Maastrichtian–Paleocene sea level fall. Enhanced subsidence on the outer shelf during the Eocene created a forced transgression with carbonate mudstonesiltstone deposition. A highstand during the Oligocene– Early Miocene formed the distinctive prograding carbonate shelf recognised throughout the North West Shelf.A Middle Neogene Supersequence (late Early Miocene– Early Pliocene) is identified by an erosive base and the development of a thin lowstand fan on the outer shelf. The supersequence is largely characterised by backstepping reefs following a Middle Miocene transgression. A Late Miocene eustatic stillstand restricted reef development to the inner shelf, generating coarsegrained carbonate progrades from highstand-shedding. The final Pliocene Supersequence (Pliocene–Recent) was initiated by a eustatic fall during the Early Pliocene and was followed by the development of a transgressive, aggrading shelf.

scholarly journals U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland

Solid Earth ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 2539-2551
Author(s):  
Luca Smeraglia ◽  
Nathan Looser ◽  
Olivier Fabbri ◽  
Flavien Choulet ◽  
Marcel Guillong ◽  
...  
Keyword(s):  
Middle Eocene ◽  
Regional Scale ◽  
Earthquake Hazard ◽  
Late Eocene ◽  
Passive Margin ◽  
Tectonic Activity ◽  
Thrust Belt ◽  
Fold And Thrust Belt ◽  
Earthquake Hazard Assessment ◽  
Alpine Foreland

Abstract. Foreland fold-and-thrust belts (FTBs) record long-lived tectono-sedimentary activity, from passive margin sedimentation, flexuring, and further evolution into wedge accretion ahead of an advancing orogen. Therefore, dating fault activity is fundamental for plate movement reconstruction, resource exploration, and earthquake hazard assessment. Here, we report U–Pb ages of syn-tectonic calcite mineralizations from four thrusts and three tear faults sampled at the regional scale across the Jura fold-and-thrust belt in the northwestern Alpine foreland (eastern France). Three regional tectonic phases are recognized in the middle Eocene–Pliocene interval: (1) pre-orogenic faulting at 48.4±1.5 and 44.7±2.6 Ma associated with the far-field effect of the Alpine or Pyrenean compression, (2) syn-orogenic thrusting at 11.4±1.1, 10.6±0.5, 9.7±1.4, 9.6±0.3, and 7.5±1.1 Ma associated with the formation of the Jura fold-and-thrust belt with possible in-sequence thrust propagation, and (3) syn-orogenic tear faulting at 10.5±0.4, 9.1±6.5, 5.7±4.7, and at 4.8±1.7 Ma including the reactivation of a pre-orogenic fault at 3.9±2.9 Ma. Previously unknown faulting events at 48.4±1.5 and 44.7±2.6 Ma predate the reported late Eocene age for tectonic activity onset in the Alpine foreland by ∼10 Myr. In addition, we date the previously inferred reactivation of pre-orogenic strike-slip faults as tear faults during Jura imbrication. The U–Pb ages document a minimal time frame for the evolution of the Jura FTB wedge by possible in-sequence thrust imbrication above the low-friction basal decollement consisting of evaporites.

First sedimentary record of the pre-obduction convergence in New Caledonia: formation of an Early Eocene accretionary complex in the north of Grande Terre and emplacement of the ‘Montagnes Blanches’ nappe

2011 ◽  
Vol 182 (6) ◽  
pp. 479-491 ◽  
Author(s):  
Pierre Maurizot
Keyword(s):  
Late Cretaceous ◽  
New Caledonia ◽  
Sedimentary Cover ◽  
Planktonic Foraminifera ◽  
Foreland Basin ◽  
Late Eocene ◽  
Passive Margin ◽  
Early Eocene ◽  
Accretionary Complex ◽  
The North

Abstract New Caledonia lies at the northern tip of the Norfolk ridge, a continental fragment separated from the east Gondwana margin during the Late Cretaceous. Stratigraphic data for constraining the convergence that led to ophiolitic nappes being obducted over Grande Terre during the Eocene are both few and inaccurate. To try and fill this gap and determine the onset of the convergence, we investigated the lithology, sedimentology, biostratigraphy and geodynamic context of the Late Cretaceous – Palaeogene sedimentary cover-rock succession of northern New Caledonia. We were able to establish new stratigraphic correlations between the sedimentary units, which display large southwest-verging overfolds detached along a basal argillite series, and reinterpret their interrelationships. The sediments from the Cretaceous-Paleocene interval were deposited in a post-rift pelagic environment and are mainly biogenic with minimal terrigenous input. From the base up, they comprise black organic-rich sulphide-bearing argillite, black chert (silicified equivalent of the argillite), micritic with chert, and micrite rich in planktonic foraminifera. These passive-margin deposits are found regionally on the Norfolk Ridge down to New Zealand, and on the Lord Howe Rise, and were controlled primarily by regional or global environmental factors. The overlying Eocene deposits mark a change to an active-margin regime with distal calciturbidite and proximal breccia representing the earliest Paleogene flysch-type deposits in New Caledonia. The change from an extensional to a compressive regime marks the beginning of the pre-obduction convergence and can be assigned fairly accurately in the Koumac–Gomen area to the end of the Early Eocene (Late Ypresian, Biozone E7) at c 50 Ma. From this period on, the post-Late Cretaceous cover in northern New Caledonia was caught up and recycled in a southwest-verging accretionary complex ahead of which flysch was deposited in a flexural foreland basin. The system prograded southwards until the Late Eocene collisional stage, when the continental Norfolk ridge entered the convergence zone and blocked it. At this point the autochthonous and parautochthonous sedimentary cover and overlying flysch of northern New Caledonia was thrust over the younger flysch to the south to form a newly defined allochthonous unit, the ‘Montagnes Blanches’ nappe, that is systematically intercalated between the flysch and the obducted ophiolite units throughout Grande Terre.

SEQUENCE STRATIGRAPHIC INTERPRETATION OF CARBONATE WIRELINE LOG MOTIFS: AN EXAMPLE FROM THE NORTH WEST SHELF OF AUSTRALIA

1998 ◽  
Vol 38 (1) ◽  
pp. 188 ◽  
Author(s):  
J.N.F. Hull ◽  
S.A. Smith ◽  
H.C. Young
Keyword(s):  
Sharp Increase ◽  
Passive Margin ◽  
Log Analysis ◽  
North West ◽  
Sequence Stratigraphic ◽  
Carbonate Sedimentation ◽  
The North ◽  
Wireline Logs ◽  
Definition Of ◽  
Sequence Boundaries

An integrated biostratigraphic, wireline and seismic sequence stratigraphic study has been conducted to constrain the timing and evolution of Late Cretaceous to Tertiary depocentres along the North West Shelf of Australia. During this study a model for the sequence stratigraphic interpretation of wireline logs in this carbonate-dominated regime has been developed.A series of readily identifiable, lowstand clastic deposits interspersed within the predominantly carbonate passive margin section of the North West Shelf provide well-defined correctable events with which to divide the section. Biostratigraphic data have indicated the presence of missing section at the base of these clastic deposits and their shelfal equivalents. These events have been correlated to define sequence boundaries that are represented on wireline log data by a sharp increase in the gamma signature. Lowstand systems tracts exhibit an irregular sonic and upwardly increasing gamma signature. Transgressive systems tracts show characteristically upward-decreasing gamma and sonic profiles. Maximum flooding surfaces have been identified as the point of cleanest carbonate sedimentation represented by gamma minima on wireline logs. Log motifs exhibiting little character have been interpreted as highstand systems tracts. On seismic these sequence stratigraphic events are represented by stratal geometries that would be expected for these systems tracts.The model has enabled the definition of a higher resolution chronostratigraphic framework for the Mid Cretaceous to Recent section of the North West Shelf than has previously been possible. Forty basin-wide events have been identified from the biostratigraphic and wireline log analysis, thirty of which can be tied throughout the Barrow, Dampier and Roebuck basins.

scholarly journals U-Pb dating of middle Eocene-middle Pleistocene multiple tectonic pulses in the Alpine foreland

2021 ◽  
Author(s):  
Luca Smeraglia ◽  
Nathan Looser ◽  
Olivier Fabbri ◽  
Flavien Choulet ◽  
Marcel Guillong ◽  
...  
Keyword(s):  
Middle Eocene ◽  
Regional Scale ◽  
Plate Boundary ◽  
Late Eocene ◽  
Passive Margin ◽  
Tectonic Activity ◽  
Middle Pleistocene ◽  
Earthquake Hazard Assessment ◽  
Alpine Foreland ◽  
Tear Fault

Abstract. Foreland fold-and-thrust belts record long-lived tectonic-sedimentary activity, from passive margin sedimentation, flexuring, and further involvement into wedge accretion ahead of an advancing orogen. Therefore, dating fault activity is fundamental for plate movement reconstruction, resource exploration, or earthquake hazard assessment. Here, we report U-Pb ages of syntectonic calcite mineralizations from four thrusts and three tear faults sampled, at the regional scale, across the Jura fold-and-thrust belt in the northwestern Alpine foreland (eastern France). Four regional tectonic phases are recognized in the middle Eocene-middle Pleistocene interval: (1) pre-orogenic faulting at 44.7 ± 2.6 and 48.4 ± 1.5 Ma associated to the uplift of the Alpine forebulge, (2) syn-orogenic thrusting at 11.4 ± 1.1, 10.6 ± 0.5, 9.7 ± 1.4, 9.6 ± 0.3, and 7.5 ± 1.1 Ma associated to possible in-sequence thrust propagation, and (3) syn-orogenic tear faulting at 10.5 ± 0.4, 9.1 ± 6.5, 7.3 ± 1.9, 5.7 ± 4.7, 4.8 ± 1.7, and at 0.7 ± 4.2 Ma including the reactivation of a pre-orogenic fault as tear fault at 3.9 ± 2.9 Ma. Previously unknown faulting events at 44.7 ± 2.6 and 48.4 ± 1.5 Ma predate by ~ 10 Ma the accepted late Eocene age for tectonic activity onset in the Alpine foreland. In addition, we dated the previously inferred strike-slip faults re-activation as tear fault. The U-Pb ages demonstrate the long-lived tectonic history at the plate boundary between European and African plates and that the deformation observed in the foreland is directly linked to continental collision.

Segmentation and structural style evolution during continental breakup: observations from the Northern Bay of Biscay passive margin (offshore France)

2020 ◽  
Author(s):  
Julie Tugend ◽  
Emmanuel Masini ◽  
Sylvie Leroy ◽  
Laurent Jolivet
Keyword(s):  
North Atlantic Ocean ◽  
Passive Margin ◽  
Distal Margin ◽  
Bay Of Biscay ◽  
Progressive Change ◽  
Continental Breakup ◽  
Passive Margins ◽  
The North ◽  
Structural Style ◽  
The Impact

<p>The extension and thinning of the continental lithosphere during rifting may eventually lead to continental breakup. Related mechanisms are recorded within the Continent-Ocean Transitions (COT) of distal passive margins, showing different, often complex, tectono-magmatic interactions as revealed by the variability of basement architectures imaged by seismic data. Different extensional structures are interpreted in the COT, including high-angle or low-angle extensional faults dipping either oceanward or continentward. This variability appears mainly controlled by the initial rheological stratification of the lithosphere and its evolution during rifting. As a result, the relative influence between lower crustal ductility, crustal embrittlement, and serpentinization of the underlying mantle are the main parameters considered to explain the structural variability observed in the COT.</p><p>In this contribution, we document the tectonic evolution of the northern Bay of Biscay passive margin and show the impact of passive margin segmentation in controlling along strike changes in structural style during rifting and continental breakup. The Bay of Biscay is a V-shaped oceanic basin, which opened during the northward propagation of the North Atlantic Ocean. Its bordering magma-poor passive margins formed subsequently to a Late Jurassic to Early Cretaceous oblique rifting and Aptian-Albian oceanic spreading onset. A large number of studies already focused on this margin revealing a first-order along strike segmentation, but the structures accommodating the passage from one to the other segment remained poorly constrained.</p><p>We used a series of reflection seismic sections and complementary marine data sets such as dredges and drilling results from the Deep Sea Drilling Project to map the structural pattern and stratigraphic evolution related to this segment transition. Our seismic interpretations and mapping of the main rift structures define a relatively loose segment transition marked by a progressive change in structural style expressed differently between the COT and the rest of the passive margin. The differences observed between the proximal and distal parts of the margin can be explained by an evolution of the nature and depth of the main fault décollement level; crustal embrittlement and serpentinization becoming important controlling parameters oceanward. However, the progressive change in structural style observed in the distal margin from west to east from oceanward dipping to mainly continentward dipping faults is more likely to be related a different accommodation of extensional deformation across the transfer zone. This segmentation occurs near major pre-existing structures identified further continentward, suggesting a key role of inheritance.</p><p>Results of this work reveal the impact of margin segmentation in controlling changes in structural style at the end of rifting. If this soft transfer zones do not seem to be observed as far as the first oceanic crust, further work is required to determine how far it can control different interplay between tectonic and magmatic processes further oceanward in the COT.</p>

Seismic stratigraphy of the Vendean-Armorican platform of the French Atlantic shelf: new insights into the history of the North Atlantic ocean

2010 ◽  
Vol 181 (1) ◽  
pp. 37-50
Author(s):  
Pedro Huerta ◽  
Jean-Noël Proust ◽  
Pol Guennoc ◽  
Isabelle Thinon
Keyword(s):  
High Resolution ◽  
Atlantic Ocean ◽  
Sea Level ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Passive Margin ◽  
Tectonic Activity ◽  
Marine Deposits ◽  
The North ◽  
The North Atlantic

Abstract The evolution of the North-Atlantic Ocean from its rifting stage during the Upper Jurassic until the present-day passive margin is recorded by the sedimentary wedge of eastern French-Atlantic platform. The study of a dense network of high resolution seismic profiles on the Vendean-Armorican platform (VAP) obtained during INSU-CNRS cruise “Geovend”, led to the characterization of the architecture of the sediment wedge preserved between the coast and Armorican margin shelf edge. This sediment wedge lies on a substratum composed of metamorphic and magmatic rocks of Palaeozoic age (Ub). The sediment wedge comprises six seismic units (U1-U6) bounded by regional unconformities: Jurassic marine succession (U1), Upper Cretaceous marine rocks (U2), Eocene-Oligocene marine deposits of the incipient VAP (U3), Miocene (U4) and Plio-Quaternary (U5) marine deposits overlain by the last sea-level rise ravinement deposits (U6). Above the basal unconformity at the top of Ub, the units are bounded by angular unconformities (top of U1, U2, U3), truncation with channel incision (top U4) or planar marine ravinement (top of U5) surfaces. Most of these unconformities are due to the tectonic activity of the bay of Biscay during the Mesozoic including (1) the North Atlantic rifting during the Jurassic to Early Cretaceous, (2) the propagation of the ocean crust and counterclockwise rotation of the Iberian block during the Aptian-Albian to Coniacian (magnetic anomaly 33–34) producing troughs at the top of U1 filled by downlapping U2 sediment wedges, (3) the Alpine compression at the origin of folding and faulting and the unconformable deposition of U3, and (4) the late compressive deformation during the Miocene that affected U4. The VAP acquires its actual configuration during U4. Sedimentation on the platform was then affected by climatically-controlled relative sea-level changes (U5 to U6) that forced U5 shelf margin sediment deposition above an incised unconformity and subsequently overlain by U6 transgressive sediment blanketing. One of the main interest of the VAP area is the existence of pre- to post-rift units that helps to decipher with high resolution seismics the long-lived evolution of the Armorican margin. Such units are preserved because of the specific characters of this area located on the flank of the former Aquitaine basin (near the “celtaquitaine” flexure) and the presence of the Rochebonne basement high. The VAP thus displays most of the tectonosedimentary evolution of the West Atlantic margins. This paper would however constitute a basis for comparisons to other examples around the Atlantic ocean and then contribute to strengthen the running models of passive margin evolution.

scholarly journals Fluvial sedimentation and its reservoir potential at foreland basin margins: A case study of the Puig-reig anticline (South-eastern Pyrenees)

2021 ◽  
Author(s):  
Xiaolong Sun ◽  
Juan Alcalde ◽  
Enrique Gomez-Rivas ◽  
Amanda Owen ◽  
Albert Griera ◽  
...  
Keyword(s):  
Foreland Basin ◽  
Late Eocene ◽  
Fluvial Deposits ◽  
The North ◽  
Early Oligocene ◽  
Depositional Processes ◽  
Clay Deposits ◽  
Matrix Porosity ◽  
Reservoir Potential ◽  
The Impact

Fluvial fans represent one of the dominant sedimentary systems at the active margins of non-marine foreland basins. The Puig-reig anticline at the north-eastern margin of the Ebro Foreland Basin (SE Pyrenees, Spain) exposes continuous outcrops of late Eocene-early Oligocene fluvial deposits, from proximal to medial fluvial fan environments. The proximal deposits, located in the northern limb of the anticline, especially in the northwest zone, are characterised by conglomerates with minor interbedded sandstones, which present thick and wide sheet-like geometries with unscoured or scoured basal surfaces. These are interpreted to be the deposits of unconfined flash floods and wide-shallow channel streams. The medial deposits, covering the rest of the anticline, consist of interbedded beds of conglomerates, sandstones and claystones, deposited from braided channel streams and overbanks. Distal deposits are found towards the south, beyond the anticline, and are characterised by sandstone and clay deposits of terminal lobes or lacustrine deltas and interdistributary bays. This study assesses the impact of the primary depositional characteristics, diagenesis and deformation of the most heterolithic portion of the system, with implications for the understanding of folded fluvial reservoirs. Diagenetic processes, mainly mechanical compaction and calcite cementation, resulted in overall low matrix porosity, with limited relatively higher porosity developed in sandstone lithofacies in the medial deposits. Deformation associated with thrusting and fold growth resulted in the formation of abundant fractures, with relatively higher fracture intensities observed in sandstone lithofacies in the anticline crest. This study shows that post depositional processes can both improve and diminish the reservoir potential of basin proximal fluvial deposits, by the development of open fracture networks and by compaction-cementation, respectively. The comparison of the Puig-reig anticline with other similar settings worldwide shows that foreland basin margin locations can be potential areas for effective reservoirs, even in the case of low matrix porosity.

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