scholarly journals About this title - Cretaceous Climate Events and Short-Term Sea-Level Changes

10.1144/sp498 ◽  
2020 ◽  
Vol 498 (1) ◽  
pp. NP-NP
Author(s):  
M. Wagreich ◽  
M. Hart ◽  
B. Sames ◽  
I. O. Yilmaz
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
Human Life ◽  
Sea Level Changes ◽  
Short Term ◽  
Deep Time ◽  
Sea Level Fluctuations ◽  
Geological Processes ◽  
Stratigraphic Framework ◽  
Geological Timescale

Sea-level constitutes a critical planetary boundary for both geological processes and human life. Sea-level fluctuations during major greenhouse phases are still enigmatic and widely discussed in terms of changing climate systems. The geological record of the Cretaceous greenhouse period provides a deep-time view on greenhouse-phase Earth system processes that facilitates a much better understanding of the causes and consequences of global, geologically short-term, sea-level changes. In particular, Cretaceous hothouse periods can serve as a laboratory to better understand a near-future greenhouse Earth. This volume presents high-resolution sea-level records from globally distributed sedimentary archives of the Cretaceous involving a large group of scientists from the International Geoscience Programme IGCP 609. Marine to non-marine sedimentary successions were analysed for revised age constraints, the correlation of global palaeoclimate shifts and sea-level changes, tested for climate-driven cyclicities, and correlated within a high-resolution stratigraphic framework of the Geological Timescale. For hothouse periods, the hypothesis of significant global groundwater-related sea-level change, i.e. aquifer-eustasy as a major process, is reviewed and substantiated.

scholarly journals An introduction to causes and consequences of Cretaceous sea-level changes (IGCP 609)

2019 ◽  
Vol 498 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Michael Wagreich ◽  
Benjamin Sames ◽  
Malcolm Hart ◽  
Ismail O. Yilmaz
Keyword(s):  
Sea Level ◽  
Sea Level Changes ◽  
Short Term ◽  
Sea Level Fluctuations ◽  
Groundwater Aquifer ◽  
Sea Level Oscillations ◽  
Short And Long Term ◽  
Geological Timescale ◽  
Land Water

AbstractThe International Geoscience Programme Project IGCP 609 addressed correlation, causes and consequences of short-term sea-level fluctuations during the Cretaceous. Processes causing several ka to several Ma (third- to fourth-order) sea-level oscillations during the Cretaceous are so far poorly understood. IGCP 609 proved the existence of sea-level cycles during potential ice sheet-free greenhouse to hothouse climate phases. These sea-level fluctuations were most probably controlled by aquifer-eustasy that is altering land-water storage owing to groundwater aquifer charge and discharge. The project investigated Cretaceous sea-level cycles in detail in order to differentiate and quantify both short- and long-term records based on orbital cyclicity. High-resolution sea-level records were correlated to the geological timescale resulting in a hierarchy of sea-level cycles in the longer Milankovitch band, especially in the 100 ka, 405 ka, 1.2 Ma and 2.4 Ma range. The relation of sea-level highs and lows to palaeoclimate events, palaeoenvironments and biota was also investigated using multiproxy studies. For a hothouse Earth such as the mid-Cretaceous, humid–arid climate cycles controlling groundwater-related sea-level change were evidenced by stable isotope data, correlation to continental lake-level records and humid–arid weathering cycles.

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.

scholarly journals Late Glacial Marine Transgression and Ecosystem Response in the Landlocked Elefsis Bay (Northern Saronikos Gulf, Greece)

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1505
Author(s):  
Katerina Kouli ◽  
Maria V. Triantaphyllou ◽  
Olga Koukousioura ◽  
Margarita D. Dimiza ◽  
Constantine Parinos ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Glacial ◽  
Ecosystem Response ◽  
Sea Level Changes ◽  
Marine Transgression ◽  
Sea Level Fluctuations ◽  
Geological Processes ◽  
Marginal Areas ◽  
Coastal Landscapes ◽  
Marine Realm

Coastal landscapes are sensitive to changes due to the interplay between surface and submarine geological processes, climate variability, and relative sea level fluctuations. The sedimentary archives of such marginal areas record in detail the complex evolution of the paleoenvironment and the diachronic biota response. The Elefsis Bay is nowadays a landlocked shallow marine basin with restricted communication to the open Saronikos Gulf. A multi-proxy investigation of a high-resolution sediment core recovered from the deepest part of the basin offered a unique opportunity to record the paleoenvironmental and aquatic ecosystem response to climate and glacioeustatic sea level changes since the Late Glacial marine transgression. The retrieved sedimentary deposits, subjected to thorough palynological (pollen, non-pollen palynomorphs, dinoflagellates), micropaleontological (benthic foraminifera, calcareous nannoplankton, ostracods), and mollusc analyses, indicates isolation of the Elefsis Bay from the Saronikos Gulf and the occurrence of a shallow freshwater paleolake since at least 13,500 cal BP, while after 11,3500 cal BP the transition towards lagoon conditions is evidenced. The marine transgression in the Elefsis Bay is dated at 7500 cal BP, marking the establishment of the modern marine realm.

Lower Cretaceous of the southern North Sea Basins: reservoir distribution within a sequence stratigraphic framework

2010 ◽  
Vol 89 (3-4) ◽  
pp. 203-237 ◽  
Author(s):  
J.M. Jeremiah ◽  
S. Duxbury ◽  
P. Rawson
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
North Sea ◽  
Depositional Environment ◽  
Rhenish Massif ◽  
Short Term ◽  
Sequence Stratigraphic ◽  
Tectonic Events ◽  
Stratigraphic Framework ◽  
First Time

AbstractFacies belts exhibit a back-stepping trend towards the London Brabant/ Rhenish Massif through the Early Cretaceous. The overall eustatic sea-level rise was punctuated by short-term tectonic events identified either as localised or North Sea wide in extent. The biostratigraphically constrained sequences have, for the first time, allowed a detailed calibration of tectonic and eustatic events on a North Sea scale. The most extensive database available to any North Sea Cretaceous study was available to the authors together with a comprehensive suite of new high-resolution biostratigraphy and sedimentology. This has allowed unique insights into provenance, depositional environment, extent of sequence stratigraphical events and the degree to which unconformities have been tectonically accentuated.

BIOINDICATORS OF SEA-LEVEL FLUCTUATIONS IN SOUTHEASTERN BRAZIL: NEW DATA AND METHODOLOGICAL REVIEW

Radiocarbon ◽  
2021 ◽  
pp. 1-15
Author(s):  
Julia Caon Araujo ◽  
Kita Chaves Damasio Macario ◽  
Vinícius Nunes Moreira ◽  
Anderson dos Santos Passos ◽  
Perla Baptista de Jesus ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Data Interpretation ◽  
Progressive Increase ◽  
Southeastern Brazil ◽  
Recrystallization Process ◽  
Sea Level Changes ◽  
Sea Level Fluctuations ◽  
Data Gap ◽  
Current Zero

ABSTRACT The vermetidae fossils of Petaloconchus varians, formed by calcium carbonate, associated with their radiocarbon ages, are the most accurate indicators of paleo sea level due to their restricted occupation in the intertidal zone in the rocky shore. However, the recrystallization of minerals can affect these age calculations and, consequently, the interpretation of the data. The aim of this study is to present new indicators of paleo sea-level changes in Southeast Brazil for the last 6000 years contributing to fill the data gap for the late Holocene. The influence of the recrystallization process was successfully resolved using the CarDS protocol, enabling the separation of the original aragonite fraction by density, prior to radiocarbon dating. This avoids the rejuvenation of ages and ensures greater efficiency for data interpretation. Paleo sea-level indicators were able to show a progressive increase in sea level up to the transgressive maximum of 4.15 m in 3700 BP years, followed by a regression to the current zero. This regression seems to have in addition, here we reinforce the reliability of the use of fossil vermetids as indicators of sea-level fluctuations.

scholarly journals High-resolution isotope stratigraphy of the Lower Ordovician St. George Group of western Newfoundland, Canada: implications for global correlation

2009 ◽  
Vol 46 (6) ◽  
pp. 403-423 ◽  
Author(s):  
Karem Azmy ◽  
Denis Lavoie
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
Sea Level Changes ◽  
Global Correlation ◽  
Lower Ordovician ◽  
Isotope Stratigraphy ◽  
Platform Carbonates ◽  
The Baltic ◽  
Marine Platform ◽  
Bottom To Top

The Lower Ordovician St. George Group of western Newfoundland consists mainly of shallow-marine-platform carbonates (∼500 m thick). It is formed, from bottom to top, of the Watts Bight, Boat Harbour, Catoche, and Aguathuna formations. The top boundary of the group is marked by the regional St. George Unconformity. Outcrops and a few cores from western Newfoundland were sampled at high resolution and the extracted micritic materials were investigated for their petrographic and geochemical criteria to evaluate their degree of preservation. The δ13C and δ18O values of well-preserved micrite microsamples range from –4.2‰ to 0‰ (VPDB) and from –11.3‰ to –2.9‰ (VPDB), respectively. The δ13Ccarb profile of the St. George Group carbonates reveals several negative shifts, which vary between ∼2‰ and 3‰ and are generally associated with unconformities–disconformities or thin shale interbeds, thus reflecting the effect of or link with significant sea-level changes. The St. George Unconformity is associated with a negative δ13Ccarb shift (∼2‰) on the profile and correlated with major lowstand (around the end of Arenig) on the local sea-level reconstruction and also on those from the Baltic region and central Australia, thus suggesting that the St. George Group Unconformity might have likely had an eustatic component that contributed to the development–enhancement of the paleomargin. Other similar δ13Ccarb shifts have been recorded on the St. George profile, but it is hard to evaluate their global extension due to the low resolution of the documented global Lower Ordovician (Tremadoc – middle Arenig) δ13Ccarb profile.

Subsurface geological imaging of northeastern Tunisia during the middle to the upper Eocene: Insights from integrated geophysical interpretation

2021 ◽  
pp. 1-64
Author(s):  
Oussama Abidi ◽  
Kawthar Sebei ◽  
Adnen Amiri ◽  
Haifa Boussiga ◽  
Imen Hamdi Nasr ◽  
...  
Keyword(s):  
Sea Level ◽  
Regional Scale ◽  
Upper Eocene ◽  
Sea Level Changes ◽  
Seismic Profiles ◽  
Borehole Data ◽  
Third Order ◽  
Good Correspondence ◽  
Basin Inversion ◽  
Sea Level Fluctuations

The Middle to Upper Eocene series are characterized by multiple hiatuses related to erosion, non-deposition or condensed series in the Cap Bon and Gulf of Hammamet provinces. We performed an integrated study taking advantage from surface and subsurface geology, faunal content, borehole logs, electrical well logs, vertical seismic profiles and surface seismic sections. Calibrated seismic profiles together with borehole data analysis reveal unconformities with deep erosion, pinchouts, normal faulting and basin inversion which are dated Campanian, intra-Lutetian and Priabonian compressive phases; these events were also described at the regional scale in Tunisia. Tectonics, sea level fluctuations and climate changes closely controlled the depositional process during the Middle to Upper Eocene time. The depositional environment ranges from internal to outer platform separated by an inherited paleo-high. We determine eight third order sequences characterizing the interaction between tectonic pulsations, sea level changes and the developed accommodation space within the Middle to Upper Eocene interval. We correlate the obtained results of the Cap Bon-Gulf of Hammamet provinces with the published global charts of sea-level changes and we find a good correspondence across third order cycles. Model-based 3D inversion proved to be a solution to model the lateral and vertical lithological distribution of the Middle to Upper Eocene series.

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.

Cenomanian to Coniacian sea-level changes in the Lower Benue Trough (Nkalagu Area, Nigeria) and the Eastern Dahomey Basin: palaeontological and sedimentological evidence for eustasy and tectonism

2019 ◽  
Vol 498 (1) ◽  
pp. 233-255 ◽  
Author(s):  
Holger Gebhardt ◽  
Samuel O. Akande ◽  
Olabisi A. Adekeye
Keyword(s):  
Sea Level ◽  
Deep Water ◽  
Close Relation ◽  
Depositional Environments ◽  
Sea Level Changes ◽  
Foraminiferal Assemblage ◽  
Benue Trough ◽  
Sea Level Fluctuations ◽  
Dahomey Basin ◽  
Lower Benue Trough

AbstractThe Benue Trough formed in close relation to the opening of the South Atlantic and experienced sea-level fluctuations of different magnitudes during the Cenomanian to Coniacian interval. We identify depositional environments from outcrop sections and a drilling as control record. Lines of evidence for the interpretation include facies analyses, foraminiferal assemblage composition (P/B-ratio) and the presence of planktonic deep-water indicators. While the analysis of the well data from the Dahomey Basin indicates a continuous deep-water (bathyal) environment, the succession in the Nkalagu area of the Lower Benue Trough evolved in a different and more complex way. Beginning with latest Cenomanian shoreface to shelf deposits, a long period of subsidence lasted until the middle Turonian when pelagic shales and calcareous turbidites were deposited at upper to middle bathyal depths. These conditions continued during late Turonian and Coniacian times. The general deepening trend of the Lower Benue Trough was mainly controlled by tectonic subsidence and was superimposed by eustatic sea-level changes, resulting in periodically changing palaeowater depths. We were able to identify eight sea-level rises and falls that can be attributed to 405 kyr eccentricity cycles. The amplitudes of the sea-level changes were most likely in the range of several tens to a few hundred metres. The deposition of carbonate turbidites at Nkalagu was probably triggered by eustatic sea-level lowstands.

Sign in / Sign up

Export Citation Format

Share Document