Latest Pliensbachian–Toarcian eustatic calibration using shallow-marine sedimentological record coupled with basinal geochemical analyzes

2020 ◽  
Author(s):  
François-Nicolas Krencker ◽  
Alicia Fantasia ◽  
Mohamed El Ouali ◽  
Lahcen Kabiri ◽  
Stéphane Bodin
Keyword(s):  
Sea Level ◽  
Special Focus ◽  
Level Fluctuation ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Sequence Stratigraphic ◽  
Sea Level Fluctuations ◽  
Anoxic Events ◽  
Chemical Index Of Alteration ◽  
Sea Level Fluctuation

<p><span>Sea-level fluctuation is an important parameter controlling the sedimentation in deep-marine environments and influenced also the expansion of oxygen-depleted conditions in neritic settings during oceanic anoxic events (OAEs). Despite this fundamental role, sea-level fluctuation remains on a short timescale (<1 Myr) one of the least constrained parameters for numerous OAEs. Here we refine the sequence stratigraphic framework for the uppermost Pliensbachian–Toarcian with a special focus on the Toarcian OAE interval. This study is based on sedimentological and total organic carbon isotope data used to correlate 16 sections located in the central High Atlas (Morocco). Palinspastically, those sections formed a 50-kilometer proximal–distal transect along the northern Gondwana continental shelf, which allow reconstructing the shoreline migration through time and space. Our sequence stratigraphic interpretation is then compared to the geochemical signals (e.g. detrital index, chemical index of alteration) measured on samples collected in deep-environment settings from numerous basins distributed worldwide. Our study shows that the relative sea-level changes recorded in Morocco can be correlated over large distances across those basins, indicating that the relative sea-level changes were driven by eustatic fluctuations. This study gives insights into the relationship between relative sea-level fluctuations and the geochemical record.</span></p>

scholarly journals Aquifer-eustasy as the main driver of short-term sea-level fluctuations during Cretaceous hothouse climate phases

2019 ◽  
Vol 498 (1) ◽  
pp. 9-38 ◽  
Author(s):  
Benjamin Sames ◽  
M. Wagreich ◽  
C. P. Conrad ◽  
S. Iqbal
Keyword(s):  
Sea Level ◽  
Phase Relationship ◽  
Sea Level Changes ◽  
Short Term ◽  
Groundwater Levels ◽  
Sequence Stratigraphic ◽  
Sea Level Fluctuations ◽  
Minimum Estimate ◽  
Underlying Mechanisms ◽  
Continental Ice Sheets

AbstractA review of short-term (<3 myr: c. 100 kyr to 2.4 myr) Cretaceous sea-level fluctuations of several tens of metres indicates recent fundamental progress in understanding the underlying mechanisms for eustasy, both in timing and in correlation. Cretaceous third- and fourth-order hothouse sea-level changes, the sequence-stratigraphic framework, are linked to Milankovitch-type climate cycles, especially the longer-period sequence-building bands of 405 kyr and 1.2 myr. In the absence of continental ice sheets during Cretaceous hothouse phases (e.g. Cenomanian–Turonian), growing evidence indicates groundwater-related sea-level cycles: (1) the existence of Milankovitch-type humid-arid climate oscillations, proven via intense humid weathering records during times of regression and sea-level lowstands; (2) missing or inverse relationships of sea-level and the marine δ18O archives, i.e. the lack of a pronounced positive excursion, cooling signal during sea-level lowstands; and (3) the anti-phase relationship of sea and lake levels, attesting to high groundwater levels and charged continental aquifers during sea-level lowstands. This substantiates the aquifer-eustasy hypothesis. Rates of aquifer-eustatic sea-level change remain hard to decipher; however, reconstructions range from a very conservative minimum estimate of 0.04 mm a−1 (longer time intervals) to 0.7 mm a−1 (shorter, probably asymmetric cycles). Remarkably, aquifer-eustasy is recognized as a significant component for the Anthropocene sea-level budget.

Foraminiferal response to Albian relative sea-level changes in northwestern and central Alberta, Canada

1999 ◽  
Vol 36 (10) ◽  
pp. 1617-1643 ◽  
Author(s):  
Rebecca A Stritch ◽  
Claudia J Schröder-Adams
Keyword(s):  
Sea Level ◽  
Bottom Water ◽  
Gradual Increase ◽  
Western Canada ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Sea Level Fluctuations ◽  
Faunal Assemblages ◽  
Water Oxygen ◽  
Southern Alberta

Albian foraminiferal assemblages from three wells in northwestern (Imperial Spirit River No. 1, 12-20-78-6W6), central (AngloHome C&E Fort Augustus No. 1, 7-29-55-21W4), and southern Alberta (Amoco B1 Youngstown, 6-34-30-8W4) provide the basis to track a fluctuating sea-level history in western Canada. Two global second-order marine cycles (Kiowa - Skull Creek and Greenhorn) were punctuated by higher frequency relative sea-level cycles expressed during the time of the Moosebar-Clearwater, Hulcross, Joli Fou, and Mowry seas. A total of 34 genera and 93 subgeneric taxa are recognized in these Albian-age strata. Foraminiferal abundance and species diversity of the latest Albian Mowry Sea were higher than in the early to middle Albian Moosebar-Clearwater and Hulcross seas. The two earliest paleo-seas were shallow embayments of the Boreal Sea, and relative sea-level fluctuations caused variable marine to brackish conditions expressed in a variety of faunal assemblages. Towards the late Albian, relative sea level rose, deepening the basin and establishing increased marine conditions and more favourable habitats for foraminifera. In the deeper Joli Fou Seaway and Mowry Sea, however, reduced bottom water oxygen through stratification or stagnant circulation caused times of diminished benthic faunas. The Bluesky Formation in northwestern Alberta contains the initial transgression of the early Albian Moosebar-Clearwater Sea and is marked by a sudden faunal increase. In contrast, transgression by the late late Albian Mowry Sea was associated with a gradual increase of foraminiferal faunas. Numerous agglutinated species range throughout the entire Albian, absent only at times of basin shallowing. However, each major marine incursion throughout the Albian introduced new taxa.

Sea-level fluctuations in the late Middle Permian estimated from palaeosols of the Sichuan Basin, SW China

2020 ◽  
Vol 157 (8) ◽  
pp. 1333-1348
Author(s):  
Jun Li ◽  
Zhong Han ◽  
Xingyue Wen ◽  
Gregory J. Retallack ◽  
Chengmin Huang
Keyword(s):  
Sea Level ◽  
Sichuan Basin ◽  
Chemical Properties ◽  
Middle Permian ◽  
Sea Level Changes ◽  
Yangtze Craton ◽  
Relative Sea Level ◽  
Carbonate Microfacies ◽  
Additional Tool ◽  
Sea Level Fluctuations

AbstractTwo upper Middle Permian palaeosols, consisting of coal and pyrite intercalated with a 20 cm thick limestone, were found near Mount Emei in the SW Sichuan Basin, China. The macro- and micromorphology and physico-chemical properties, in conjunction with the mineralogical composition of the palaeosol horizons were investigated. This type of palaeosol is common within the Permian intertidal facies of the Upper Yangtze Craton. The section reflects fluctuations within the range of 0–25 m in relative sea-level, with the depositional environment changing from shallow-marine to littoral, followed by tidal-flat to littoral, and finally to continental volcanic rocks, based on a combination of palaeopedological and carbonate microfacies analyses. Such short-term relative sea-level fluctuations in late Middle Permian times in the SW Sichuan Basin of South China are consistent with the long-term falling trend on a global scale in late Middle Permian times, and may be related to regionally variable subsidence and global cooling. The combination of coastal palaeosol and carbonate microfacies analyses is proposed as an additional tool for estimating the amplitude of sea-level changes.

Sea Level Fluctuation During the Past 6000 yr at the Coast of Mauritania

1974 ◽  
Vol 4 (3) ◽  
pp. 282-289 ◽  
Author(s):  
G. Einsele ◽  
D. Herm ◽  
H.U. Schwarz
Keyword(s):  
Sea Level ◽  
High Accuracy ◽  
Level Fluctuation ◽  
Sea Level Changes ◽  
Tidal Zone ◽  
The Past ◽  
Marine Terraces ◽  
Open Sea ◽  
Sea Level Fluctuation ◽  
Ecological Methods

In an area regarded to be very favorable for the study of Holocene sea level changes one or several eustatic (?) oscillations of sea have been found using sedimentological and ecological methods. After a maximum of +3 m during the Nouakchottian stage (= Middle Flandrian or Late Atlantic) about 5500 YBP a drop of sea to −3.5 ± 0.5 m about 4100 YBP is testified by stromatolitic algae indicating the former sea level within the tidal zone with high accuracy. This evidence is supported by the observation of post-Nouakchottian regressive and transgressive geologic sequences, by buried beach deposits and flooded hardgrounds, post-Nouakchottian marine terraces of different height and age, the cutting off of one large and several small bays from the open sea, etc. Possibly one or two smaller oscillations followed between 4000 and 1500 YBP (derived sea level curve Fig. 3).

scholarly journals The Bakken Formation - understanding the sequence stratigraphic record of low-gradient sedimentary systems, shale depositional environments, and sea-level changes in an icehouse world

2020 ◽  
Vol 18 (4) ◽  
pp. 4-9
Author(s):  
Sven O Egenhoff ◽  
Neil S Fishman
Keyword(s):  
Sea Level ◽  
High Amplitude ◽  
Depositional Environments ◽  
Ice Age ◽  
Bakken Formation ◽  
Sea Level Changes ◽  
Sequence Stratigraphic ◽  
Sea Level Fluctuations ◽  
Layer Cake ◽  
Low Amplitude

The Bakken Formation is a major petroleum producer in the continental US. However, its deposition in an intracratonic, low-gradient setting has often been mistakenly described as “layer-cake”. This contribution is designed to highlight the time-transgressive nature of its main petroleum-producer, the middle Bakken member. Correlation of individual parasequences reveal the subtle nature of otherwise invisible low-angle stratigraphic geometries. Sequence stratigraphically-relevant surfaces occur throughout the unit and subdivide the entire Bakken into 5 third-order sequences; one of them is a hidden sequence at the base of the petroleum-producing middle Bakken indicating both a lowstand and a subsequent transgression. The organic-rich shales above and below the middle Bakken were deposited in an oxygen-deficient environment and show several burrow/fecal string types and indications of active currents during deposition. The Bakken records high amplitude sea-level changes during sequences compared to relative low amplitude sea-level changes of parasequences. This, coupled with a likely mismatch in timing of Bakken deposition relative to world-wide ice-age-induced cyclicity makes it unlikely that the Bakken sea-level fluctuations were dominated by glaciation.

Relative land-sea-level changes in southeastern England during the Pleistocene

1972 ◽  
Vol 272 (1221) ◽  
pp. 87-98 ◽  
Keyword(s):  
Sea Level ◽  
Sea Level Change ◽  
Estuarine Sediments ◽  
Level Fluctuation ◽  
Sea Level Changes ◽  
Freshwater Sediments ◽  
Marine Deposits ◽  
Level Change ◽  
Lower Pleistocene ◽  
Sea Level Fluctuation

During the Pleistocene, a period covering the last two million years, sea level is known to have risen above and fallen below the present sea level. The evidence for such fluctuations comes from marine and estuarine sediments, including beaches, far above present sea level and from freshwater sediments, beaches and valley systems now submerged. In southeast England there are Lower Pleistocene marine deposits at 183 m O.D . at Netley Heath in Surrey and upper Pleistocene freshwater sediments at - 35 m O.D . in the Channel. Thus we have in this area evidence of an amplitude of sea-level fluctuation relative to the present sea level of some 218 m. While such limits of relative sea-level fluctuation are not so difficult to identify, very considerable difficulties arise in determining the relation of sea-level change to the passage of time, and in the analysis of sea-level change - whether it be a real lowering of sea level relative to land, or an uplift of land relative to sea level. Let us briefly consider each of these two fields of difficulty. To date a particular stand of sea level, we have to know the relation of a particular deposit, say beach or shallow marine sediment to sea level at the time, and we have to know the correlation of this deposit to a part of the sequence of geological events which make up the Pleistocene. Both of these aspects may be problematical. It may not be certain what depth of water a deposit was formed in, and the age and correlation of the deposit may be doubtful.

scholarly journals The use of piezocone tests for high-resolution stratigraphy of Quaternary sediment sequences in the Brazilian coast

2007 ◽  
Vol 79 (1) ◽  
pp. 153-170 ◽  
Author(s):  
Giuliano de Mio ◽  
Heraldo L. Giacheti
Keyword(s):  
Sea Level ◽  
Sedimentary Environment ◽  
Brazilian Coast ◽  
Level Fluctuation ◽  
Test Results ◽  
Sea Level Fluctuations ◽  
Sedimentary Sequences ◽  
Sea Level Fluctuation ◽  
The Subject ◽  
Good Agreement

Correlations between mapping units of costal sedimentary basin and interpretation of piezocone test results are presented and discussed based on examples from Caravelas strandplain, (State of Bahia), Paranaguá (State of Paraná) and Guarujá bays (State of São Paulo), Brazil. Recognizing that the sedimentary environment was mainly controlled by sea level fluctuations led to the interpretation of transgressive and regressive sedimentary sequences, which is in a good agreement with the sea level fluctuation curves currently accepted for these regions. The interpretation of piezocone test results shows that the sedimentary sequences of Caravelas and Guarujá sites are similar and they have a good correlation to the sea level fluctuation curve accepted for Salvador region, State of Bahia. On the other hand, the piezocone test results from Paranaguá site indicate a different sedimentary sequence from the previous ones, relating to the sea level fluctuation curve accepted for Paranaguá region. The results show the high applicability of piezocone testing for stratigraphical logging and suggest that it is possible to integrate it with other current techniques used for paleo-environmental studies in Brazil, in accordance with recent approaches used in international research on the subject.

scholarly journals Depositional environment of the Branch Sandstone and correlative sequences: Late Cretaceous changes in relative sea level in the East Coast Basin of New Zealand

2021 ◽  
Author(s):  
◽  
Lisa McCarthy
Keyword(s):  
Sea Level ◽  
East Coast ◽  
Depositional Environments ◽  
Passive Margin ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Sea Level Fluctuations ◽  
The North ◽  
Tasman Sea ◽  
History Of

<p>The Branch Sandstone is located within an overall transgressive, marine sedimentary succession in Marlborough, on the East Coast of New Zealand’s South Island. It has previously been interpreted as an anomalous sedimentary unit that was inferred to indicate abrupt and dramatic shallowing. The development of a presumed short-lived regressive deposit was thought to reflect a change in relative sea level, which had significant implications for the geological history of the Marlborough region, and regionally for the East Coast Basin.  The distribution and lithology of Branch Sandstone is described in detail from outcrop studies at Branch Stream, and through the compilation of existing regional data. Two approximately correlative sections from the East Coast of the North Island (Tangaruhe Stream and Angora Stream) are also examined to provide regional context. Depositional environments were interpreted using sedimentology and palynology, and age control was developed from dinoflagellate biostratigraphy. Data derived from these methods were combined with the work of previous authors to establish depositional models for each section which were then interpreted in the context of relative sea level fluctuations.  At Branch Stream, Branch Sandstone is interpreted as a shelfal marine sandstone, that disconformably overlies Herring Formation. The Branch Sandstone is interpreted as a more distal deposit than uppermost Herring Formation, whilst the disconformity is suggested to have developed during a fall in relative sea level. At Branch Stream, higher frequency tectonic or eustatic sea-level changes can therefore be distinguished within a passive margin sedimentary sequence, where sedimentation broadly reflects subsidence following rifting of the Tasman Sea. Development of a long-lived disconformity at Tangaruhe Stream and deposition of sediment gravity flow deposits at Angora Stream occurred at similar times to the fall in relative sea level documented at the top of the Herring Formation at Branch Stream. These features may reflect a basin-wide relative sea-level event, that coincides with global records of eustatic sea level fall.</p>

Lower Silurian reefs and post-reef beds of the Attawapiskat Formation, Hudson Bay Platform, northern Ontario

1993 ◽  
Vol 30 (3) ◽  
pp. 575-590 ◽  
Author(s):  
Daniel R. Suchy ◽  
Colin W. Stearn
Keyword(s):  
Debris Flow ◽  
Sea Level ◽  
Hudson Bay ◽  
Burial Diagenesis ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Northern Ontario ◽  
Sea Level Fluctuations ◽  
Wide Range ◽  
History Of

Outcrop exposures along the Attawapiskat River in the Hudson Bay Lowlands of northern Ontario clearly reveal the morphology of Silurian (upper Llandoverian) reefs of the Attawapiskat Formation and the relationships between reef cores, flanking beds, and post-reef beds. These relationships indicate that the reefs had a syndepositional relief of at least 8–10 m. The relief of the reefs is indicated by debris-flow lenses encased within flanking beds, a debris-flow fan at the base of a reef, thin reef-flanking beds truncated against a vertical reef face, penecontemporaneous brachiopod beds on the flanks of reefs, and three large slide blocks that apparently slid over the side of a reef.Reefs of the Attawapiskat Formation are largely limestones with a wide range of lithologies, from stromatoporoid-, coral-, and cement-rich boundstones to alga–cement-rich boundstones. Thick, laterally extensive Nuia grainstone beds, a product of widespread Nuia monocultures in supratidal to intertidal ponds, are present above the reefs. The most important diagenetic processes were early marine cementation (predominantly radial-fibrous calcite), shallow burial diagenesis, and pervasive neomorphism.Schematic reconstructions of the depositional history of the Attawapiskat Formation in outcrop, constructed from observations of outcrop relationships, show a stratigraphic succession that was controlled by relative-sea-level changes. Reefs growth was terminated by a relative-sea-level fall, but subsequent minor relative-sea-level fluctuations resulted in alternating deposition of supratidal to shallow subtidal sediments for a short time before the final retreat of the Silurian seas from the Hudson Bay Platform; only supratidal evaporite facies are present in the remainder of the Silurian section above the Attawapiskat Formation.

scholarly journals Beach-Foredune Sediment Budget Response to Sea Level Fluctuation. Curonian Spit, Lithuania

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 583 ◽  
Author(s):  
Darius Jarmalavičius ◽  
Donatas Pupienis ◽  
Gintautas Žilinskas ◽  
Rasa Janušaitė ◽  
Viktoras Karaliūnas
Keyword(s):  
Sea Level ◽  
Sediment Budget ◽  
Level Fluctuation ◽  
Curonian Spit ◽  
Decadal Time Scale ◽  
Beach Sediment ◽  
Minimal Impact ◽  
Sea Level Fluctuations ◽  
Sediment Volume ◽  
Sea Level Fluctuation

Beach-foredune sediment exchange maintains a coastal system’s stability. Sea level fluctuation is one of the most important factors that modifies the beach and foredune sediment budget. This study aims to assess beach and foredune sand budget changes depending on sea level fluctuations. On the basis of annual measurements of cross-shore profiles on the Curonian Spit in Lithuania, the sediment volumes on the beach and foredune and their changes between 2002 and 2019 were calculated. The sea level fluctuations were examined in parallel. The obtained data revealed that in the case of a sand surplus, a relatively low sea level rise does not have a significant impact on the development of a foredune (and a minimal impact on a beach) on a decadal time-scale. Short-term sea level fluctuations are reflected in year-to-year variability in a beach sediment budget. However, no significant relationship between year-to-year variability in sea level fluctuation and the foredune sediment budget has yet been identified, nor is there a reliable year-to-year variability relationship between the foredune and beach sediment budget. The foredune sediment budget remained positive both through an increase and a reduction in the sediment volume on the beach.

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