Morphology, architecture, and evolutionary processes of the Zhongjian Canyon between two carbonate platforms, South China Sea

2018 ◽  
Vol 6 (4) ◽  
pp. SO1-SO15 ◽  
Author(s):  
Yintao Lu ◽  
Wei Li ◽  
Shiguo Wu ◽  
Bryan T. Cronin ◽  
Fuliang Lyu ◽  
...  
Keyword(s):  
Seismic Data ◽  
Large Scale ◽  
Middle Miocene ◽  
Sedimentary Environment ◽  
Submarine Canyon ◽  
High Amplitude ◽  
Seismic Facies ◽  
Coarse Grained ◽  
Carbonate Platforms ◽  
Depositional Processes

Two isolated Neogene carbonate platforms (Xisha and Guangle carbonate platforms) have developed in the rifted uplifts since the Early Miocene. A large-scale submarine canyon system, the Zhongjian Canyon (ZJC), has developed in the tectonic depression between the two platforms since the Middle Miocene. High-resolution bathymetry data and 2D and 3D seismic data reveal the existence of the ZJC on the present seafloor, as well as in Neogene intervals. It exhibits typical characteristics of deepwater canyons that cut the surrounding rocks and indicate strong erosional features. The ZJC resulted from northwest–southeast strike-slip fault activities during synrift and postrift stages, and it periodically grew during the development of carbonate platforms since the Middle Miocene. We identified four cycles of parallel to subparallel high amplitude and dim reflectors in seismic data, which we interpreted as alternating canyon fill, based on the interpretation of seismic facies. Thus, the sedimentary evolution of the ZJC can be divided into four typical stages, which were in the Middle Miocene, Late Miocene, Early Pliocene, and Pleistocene. Considering the tectonic background of the carbonate platforms, as well as the on-going igneous activities, the sediment filling the canyon could be derived from a mixture of carbonate clasts, igneous clasts, mud, and silt. The laminar high-amplitude reflectors and dim-reflector package represented a fining-upward sedimentary cycle. The coarse-grained sediment in canyon fillings could be turbidites, carbonate debrites, and even igneous clasts. In contrast, the fine-grained sediment is likely to be dominated by pelagic to hemipelagic mud, and silt. This case study describes a deepwater canyon under a carbonate-dominated sedimentary environment and has significant implications for improving our knowledge of periplatform slope depositional processes. Furthermore, the insight gained into periplatform slope depositional processes can be applied globally.

scholarly journals Eustatic, Climatic, and Oceanographic Influences on Geomorphology and Architecture of Isolated Carbonate Platforms: Miocene, Northwest Shelf, Australia

Lithosphere ◽  
2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Eugene C. Rankey
Keyword(s):  
Seismic Data ◽  
Middle Miocene ◽  
Seismic Facies ◽  
Global Changes ◽  
Carbonate Platforms ◽  
Stratigraphic Subdivision ◽  
Complex Architecture ◽  
Stacking Patterns ◽  
3D Seismic Data

Abstract The Miocene represents an interval of marked global change, and this evolution is reflected in carbonate platforms from this epoch. Seismic stratigraphic characterization of high-resolution (ca 60 Hz) 3D seismic data from the Browse Basin, offshore Australia, reveals a middle to upper Miocene three-part seismic stratigraphic subdivision. Each unit consists of several seismic sequence sets and their component sequences. Seismic stratal geometries and seismic facies define a prograding shelf (Langhian and older), a barrier-reef complex with scattered platforms (upper Langhian–early Tortonian), and aggrading and prograding isolated platforms (early Tortonian–Messinian). The data permit description and interpretation of high-fidelity stratigraphic details of the initiation, expansion, termination, and geomorphology of over 100 platforms in this interval. The results reveal that the isolated platforms initiated following the Middle Miocene Climatic Optimum. The succession includes major seismic stratigraphic boundaries and overall patterns of platform growth and demise that correspond roughly with periods of pronounced eustatic change associated with initiation of eastern Antarctic ice sheets. Although invoking a eustatic control for coarse trends may be tempting, mismatch between the numbers and ages of sequences, as well as the variable stacking patterns among contemporaneous platforms regionally, precludes such an interpretation; conversely, some globally recognized eustatic changes do not have a pronounced manifestation in this area. Thus, it appears that the eustatic signal combined with dynamic physical regional processes such as waves, currents, and variable subsidence creates the complex architecture and geomorphology of platforms. These results illustrate how global changes can interact with local controls to create diverse patterns of birth, growth, and demise of carbonate platforms and drive local stratal heterogeneity.

scholarly journals Seismic characterisation of carbonate platforms and reservoirs: an introduction and review

2021 ◽  
pp. SP509-2021-51
Author(s):  
J. Hendry ◽  
P. Burgess ◽  
D. Hunt ◽  
X. Janson ◽  
V. Zampetti
Keyword(s):  
Seismic Data ◽  
Large Scale ◽  
Carbonate Platform ◽  
Energy Transition ◽  
Carbonate Platforms ◽  
Seismic Attribute ◽  
Sequence Stratigraphic ◽  
3D Data ◽  
Diagenetic Facies ◽  
Central Atlantic

AbstractImproved seismic data quality in the last 10–15 years, innovative use of seismic attribute combinations, extraction of geomorphological data, and new quantitative techniques, have significantly enhanced understanding of ancient carbonate platforms and processes. 3D data have become a fundamental toolkit for mapping carbonate depositional and diagenetic facies and associated flow units and barriers, giving a unique perspective how their relationships changed through time in response to tectonic, oceanographic and climatic forcing. Sophisticated predictions of lithology and porosity are being made from seismic data in reservoirs with good borehole log and core calibration for detailed integration with structural, paleoenvironmental and sequence stratigraphic interpretations. Geologists can now characterise entire carbonate platform systems and their large-scale evolution in time and space, including systems with few outcrop analogues such as the Lower Cretaceous Central Atlantic “Pre-Salt” carbonates. The papers introduced in this review illustrate opportunities, workflows, and potential pitfalls of modern carbonate seismic interpretation. They demonstrate advances in knowledge of carbonate systems achieved when geologists and geophysicists collaborate and innovate to maximise the value of seismic data from acquisition, through processing to interpretation. Future trends and developments, including machine learning and the significance of the energy transition, are briefly discussed.

Characteristics and origins of ridges and troughs on the top of the Middle Miocene strata in the Beijiao sag of the Qiongdongnan basin, northern South China Sea

2020 ◽  
pp. 1-57
Author(s):  
Yufeng Li ◽  
Renhai Pu ◽  
Gongcheng Zhang ◽  
Hongjun Qu
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Middle Miocene ◽  
Northern South China Sea ◽  
Qiongdongnan Basin ◽  
Coarse Grained ◽  
Bottom Currents ◽  
Fine Grained ◽  
Sediment Waves ◽  
History Of

Sedimentary structures generated by bottom currents are poorly understood worldwide. Ridges and troughs are imaged for the first time by 3D high-resolution seismic data and drilled by a well, YL19-1-1, in the Beijiao sag of Qiongdongnan basin (QDNB). Combined with 2D high resolution seismic data, they are analyzed in detail. The results show that ridges and troughs occur on the top of the Middle Miocene, dominantly present a wave-shaped structure. Their magnitudes are larger on the middle (regional) slope than on the upper and lower slope. They extend for tens of kilometers, dominantly parallel to one another, evenly spaced and nearly E-W directed distribution, some of which locally merge and bifurcate. They are aligned oblique to the regional slope. Both internal mounded reflections and parallel underlying-strata reflections, occur within ridges. The presence of polygonal faults and weak-to-moderate amplitudes within the ridges and troughs, suggests that they consist of fine-grained mudstones, as confirmed by well YL19-1-1. High amplitudes filled within troughs are probably composed of coarse-grained turbidite sandstones where polygonal faults are inhibited. Truncated reflections and onlaps occur along the thalweg of a trough, and are also clearly observed on the sides of ridges and troughs. We conclude the troughs are a product of erosion of bottom currents, and ridges are remnant underlying (sediment waves) strata as a result of this erosion. Besides, troughs are filled by turbidite sandstones with high amplitudes in the southwestern part of the study area, where ridges and troughs a combined result of early erosion by bottom currents and later reworking by turbidity flows. Conceptual schematic models are proposed to show the evolutionary history of ridges and troughs. This study provides new insights into further understanding of erosion and deposition of bottom currents.

A statistical methodology for deriving reservoir properties from seismic data

Geophysics ◽  
1995 ◽  
Vol 60 (5) ◽  
pp. 1437-1450 ◽  
Author(s):  
Frédérique Fournier ◽  
Jean‐François Derain
Keyword(s):  
Seismic Data ◽  
Large Scale ◽  
Seismic Attributes ◽  
Seismic Facies ◽  
Reservoir Properties ◽  
Data Set ◽  
Analysis Technique ◽  
Seismic Facies Analysis ◽  
Statistical Relationships

The use of seismic data to better constrain the reservoir model between wells has become an important goal for seismic interpretation. We propose a methodology for deriving soft geologic information from seismic data and discuss its application through a case study in offshore Congo. The methodology combines seismic facies analysis and statistical calibration techniques applied to seismic attributes characterizing the traces at the reservoir level. We built statistical relationships between seismic attributes and reservoir properties from a calibration population consisting of wells and their adjacent traces. The correlation studies are based on the canonical correlation analysis technique, while the statistical model comes from a multivariate regression between the canonical seismic variables and the reservoir properties, whenever they are predictable. In the case study, we predicted estimates and associated uncertainties on the lithofacies thicknesses cumulated over the reservoir interval from the seismic information. We carried out a seismic facies identification and compared the geological prediction results in the cases of a calibration on the whole data set and a calibration done independently on the traces (and wells) related to each seismic facies. The later approach produces a significant improvement in the geological estimation from the seismic information, mainly because the large scale geological variations (and associated seismic ones) over the field can be accounted for.

Sedimentary Processes on a Mixed Turbidite-Contourite System - Northern Campos Basin, SE Brazil

2021 ◽  
Author(s):  
Bruna Teixeira Pandolpho ◽  
Antonio Henrique da Fontoura Klein ◽  
Isadora Dutra ◽  
Michel M. Mahiques ◽  
Adriano R. Viana ◽  
...  
Keyword(s):  
Intermediate Stage ◽  
High Amplitude ◽  
Seismic Facies ◽  
Seismic Unit ◽  
Sediment Waves ◽  
Depositional Processes ◽  
Campos Basin ◽  
Low Amplitude ◽  
Rms Amplitude ◽  
Mixed Systems

<p>A new mixed turbidite-contourite system is described in the northern Campos Basin, southeastern Brazilian margin. This system is developed in a middle slope setting and was formed through non-synchronous interaction between the turbidity current and a contour current in the same stratigraphic interval (Miocene). Different depositional cycles were accounted based on their diagnostic seismic features. Seismic attributes, seismic facies, and isochron maps were used to identify alternating cycles of downslope and alongslope processes in the study area, along with the intermediate stage with features from both processes (mixed system). Seismic units were then associated with the dominant type of current. Depositional processes resulted from alongslope current activity can be distinguished from the downslope current activity, based on the acoustic characteristics (root-mean-square (RMS) amplitude values), internal architecture, and external geometry pattern. While alongslope currents deposits consist of mainly low RMS amplitude values clinoforms with an alongslope trend; the downslope gravity deposits present high-amplitude or chaotic seismic facies, usually higher values of RMS amplitude, channel or channel-lobe features, erosive surfaces, and a basinward depositional trend. The first and oldest seismic unit (S1) was interpreted as a dominantly alongslope system, with aggrading sigmoidal clinoforms and high-frequency, low-amplitude reflections commonly associated with fine-grained sedimentary deposits, typical of a plastered drift. Basinward mass transport deposit derived from previous drift instability are often identified. Seismic unit S2 represents the intermediate stage where both gravity-driven and along-slope currents act asynchronously. It is referred to as a mixed turbidite-contourite sequence that shows high-amplitude sediment waves migrating upslope and a moat feature carved in its upslope front. The interfingering between high- and low-amplitude reflectors, distal chaotic facies, together with sediment waves and a channel moat, points to a sand-rich deposit reworked by northward-flowing contour currents. Seismic units S3 and S4 show downslope features with chaotic facies (S3) and paleochannels with coarse basal lag deposits interpreted after the high RMS amplitude values (S4). In S4, a series of long-lived submarine channels formed. The last seismic unit, S5, referred to as the second plastered drift sequence, is marked by low-amplitude clinoforms that thin basinward. Important information on the paleocurrents' direction was also made based on the final deposits display (e.g. terraces, sediment waves, paleochannels), where a northward-flowing bottom current was assumed. Research on alternating dominant processes and transitional stages or mixed depositional systems may provide a better understanding of deep-water depositional processes. Because these processes do not always fit previous depositional models that are mainly described for synchronous systems, new insights on cyclic non-synchronous mixed systems can improve our understanding of how mixed systems are organized through time and space. We can also determine which were the dominant processes that controlled the sedimentation by indicating periods where the margin was mostly submitted to sediment transfer from continent to the basin and periods where the oceanic currents prevailed by redistributing sediments along the isobaths and replacing the axis of downslope transfer conduits. Setting new models on cyclic deposits and intermediate stages can have a future economic impact on potential hydrocarbon reservoir architecture.</p>

Geochronology and sedimentary environment at the Udu-dong archeological site, Chuncheon, South Korea

The Holocene ◽  
2018 ◽  
Vol 28 (9) ◽  
pp. 1512-1522
Author(s):  
Seungwon Shin ◽  
Yong-Hee Park ◽  
Jeong-Heon Choi ◽  
Hyoun Soo Lim ◽  
Sook-Chung Shin ◽  
...  
Keyword(s):  
South Korea ◽  
Large Scale ◽  
Sedimentary Environment ◽  
Sedimentary Facies ◽  
Human Settlement ◽  
Depositional Processes ◽  
Settlement Site ◽  
Archeomagnetic Dating ◽  
Geochronological Dating ◽  
Archeological Site

The Udu-dong archeological site in Chuncheon, South Korea, dates back to the Proto–Three Kingdoms Period (approximately 100 BC to AD 350). Many artifacts, including some earthenware, have been excavated in these ancient dwelling sites. We applied three geochronological dating methods (radiocarbon, optically stimulated luminescence (OSL), and archeomagnetic dating) to the archeological remains of this large-scale human settlement and reconstructed the history of depositional processes prior to human settlement. The timing of the ancient community’s settlement was investigated by radiocarbon dating of the charcoal fragments collected from old furnaces. Archeomagnetic dating allowed us to constrain the time period of the settlement’s abandonment by dating the last use of fire. The timing and development of fluvial deposits underlying the settlement site were reconstructed by OSL dating combined with sedimentary facies analysis. Our results show that, following the deposition of coarse sediments starting 10,000 years ago, the region formed a stable floodplain environment starting around 3000 years ago; people began to form clustered settlements approximately 50 years later. For the subsequent 150 years or so, the area was heavily used as a settlement site, with people evenly distributed across it, before eventual abandonment of the site around AD 200–250. Because the sedimentary deposits do not show any significant facies change during this period, we conclude that any catastrophic events were not the main reason for settlement abandonment. This study suggests that combining scientific and archeological analyses have significant benefits for studies of such archeological sites. Therefore, continuous collection of such data can provide important information for the excavation and protection of prehistoric or historic sites.

Seismic lithostratigraphy of deep subsalt Permo‐Carboniferous gas reservoirs, Northwest German Basin

Geophysics ◽  
1990 ◽  
Vol 55 (10) ◽  
pp. 1357-1365 ◽  
Author(s):  
M. E. Mathisen ◽  
M. Budny
Keyword(s):  
Seismic Data ◽  
High Amplitude ◽  
Seismic Facies ◽  
Gas Reservoirs ◽  
Upper Carboniferous ◽  
Reservoir Sandstones ◽  
Low Amplitude ◽  
Coal Measures ◽  
Zero Phase ◽  
German Basin

Recent improvements in land seismic data quality have made it possible to initiate lithostratigraphic interpretations of deep (4000–5500 m; 2.2–2.8 s) subsalt Permo‐Carboniferous gas reservoirs in the Northwest German Basin. The first modeling and interpretation results indicate that the reflection character of Permian reservoir dolomites and sandstones can be interpreted to predict lithology and porosity variations using reflection character analysis. These formations are commonly thick enough to be resolved (>20 m) and typically have velocities 1000 to 2000 m/s slower than overlying and underlying nonreservoir rocks. Deeper Upper Carboniferous reservoir sandstones occur within a discontinuous low‐amplitude seismic facies which can be clearly differentiated from a continuous high‐amplitude facies formed by the less prospective Upper Carboniferous coal measures. The accuracy of Permian reflection character interpretations is dependent on the availability of high‐frequency, zero‐phase, relative amplitude seismic data. New 3-D data are appropriate but of limited availability. To provide suitable 2-D data, wavelet processing of selected variable vintage lines was completed. More routine use of wavelet processing and lithostratigraphic interpretation methods should help to better define reservoir facies and stratigraphic traps, lower prospect risk, and increase success ratios.

Deepwater debrites and linked megaturbidites in confined basins: An example from the Onnuri Basin, East Sea of Korea

2021 ◽  
Vol 91 (1) ◽  
pp. 1-20
Author(s):  
Deniz Cukur ◽  
In-Kwon Um ◽  
Jong-Hwa Chun ◽  
Gwang-Soo Lee ◽  
Gee-Soo Kong ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Slope Failure ◽  
Sedimentary Facies ◽  
High Amplitude ◽  
Seismic Facies ◽  
East Sea ◽  
Turbidity Currents ◽  
Radiocarbon Dates ◽  
Depositional Processes

ABSTRACT We analyzed data from seven piston cores, multi-channel seismic-reflection (MCS) and chirp profiles, and multibeam echosounder (MBES) data to study the distribution, emplacement time, sedimentary facies, and depositional processes of sediment-gravity-flow deposits in the Onnuri Basin, a confined basin in the East Sea. These data reveal that debris flows have traveled ca. 30 km downslope, forming a seismic facies consisting of stacked, wedge-shaped, transparent units separated by high-amplitude continuous reflectors. Analysis of piston cores shows three distinct sedimentary units, throughout the basin. The lowest unit, I, is a debrite containing numerous mud clasts of varying size and color distributed in a mud-rich matrix; it is absent over elevated basinal highs or ridges, such as the Onnuri Ridge, suggesting that local topography controls its distribution. The debrite forms a recognizable acoustically transparent layer on subbottom chirp profiles (av. 7 m thick), covers approximately 500 km2, and has an estimated volume of ∼ 3.5 km3. The overlying unit, II, contains normally graded beds composed of massive sand, laminated and cross-laminated sand and silt, and a thick cap of structureless mud. This unit is interpreted to be a megaturbidite deposited from turbidity currents that originated from the flow transformation of debris flows on the upper continental slope. The megaturbidite covers the entire basin (at least 650 km2), and has an average thickness of 2.8 m (maximum thickness of 4.35 m), and comprises a volume of 1.8 km3. Variations in grain size and sedimentary structures suggest that the megaturbidite was deposited by progressively waning flows that reflected off basin flanks and ridges. The thick (up to 3.65 m) structureless mud cap further indicates deposition in a confined basin. The sharp basal contact, together with the lack of hemipelagic sediments between debrite and overlying megaturbidite, suggest that both were deposited during the same flow event, likely to have originated from a single catastrophic slope failure. Collapsing slide material evolved into a debris flow, from which a turbidite formed by dilution of the debris flow. Radiocarbon dates suggest that the slope failure occurred about 13–11 ka, a time when sea level was ca. 50 m lower than at the present day. Hemipelagic sediments in the topmost unit, III-2, above the megaturbidite indicate that the basin has been stable since ca. 11 ka. We provide robust evidence that submarine slope failures evolve downslope into slides, debris flows, and finally, thick megaturbidites. This contribution highlights the importance of seafloor morphology on the distribution and stratigraphy of submarine flows in confined basins.

scholarly journals Submarine mass failures as tsunami sources: their climate control

2010 ◽  
Vol 368 (1919) ◽  
pp. 2417-2434 ◽  
Author(s):  
D. R. Tappin
Keyword(s):  
Submarine Canyon ◽  
Coarse Grained ◽  
Sediment Type ◽  
Potential Hazard ◽  
Convergent Margins ◽  
Climate Control ◽  
River Deltas ◽  
Storm Waves ◽  
Depositional Processes ◽  
Climate Controls

Recent research on submarine mass failures (SMFs) shows that they are a source of hazardous tsunamis, with the tsunami magnitude mainly dependent on water depth of failure, SMF volume and failure mechanism, cohesive slump or fragmental landslide. A major control on the mechanism of SMFs is the sediment type, together with its post-depositional alteration. The type of sediment, fine- or coarse-grained, its rate of deposition together with post-depositional processes may all be influenced by climate. Post-depositional processes, termed sediment ‘preconditioning’, are known to promote instability and failure. Climate may also control the triggering of SMFs, for example through earthquake loading or cyclic loading from storm waves or tides. Instantaneous triggering by other mechanisms such as fluid overpressuring and hydrate instability is controversial, but is here considered unlikely. However, these mechanisms are known to promote sediment instability. SMFs occur in numerous environments, including the open continental shelf, submarine canyon/fan systems, fjords, active river deltas and convergent margins. In all these environments there is a latitudinal variation in the scale of SMFs. The database is limited, but the greatest climate influence appears to be in high latitudes where glacial/interglacial cyclicity has considerable control on sedimentation, preconditioning and triggering. Consideration of the different types of SMFs in the context of their climate controls provides additional insight into their potential hazard in sourcing tsunamis. For example, in the Atlantic, where SMFs are common, the tsunami hazard under the present-day climate may not be as great as their common occurrence suggests.

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