Late Cretaceous to Early Paleogene global sea level fluctuations and the sedimentary environment in central Alborz (Northern Iran)

2020 ◽  
Vol 13 (23) ◽  
Author(s):  
Javad Rabbani ◽  
Reza Emamgholi ◽  
Nasrollah Abbassi ◽  
Mohammad Saeed Shariatzadeh
Keyword(s):  
Sea Level ◽  
Late Cretaceous ◽  
Sedimentary Environment ◽  
Northern Iran ◽  
Sea Level Fluctuations ◽  
Central Alborz ◽  
Global Sea Level ◽  
Early Paleogene

Middle to late-Holocene decreased fluvial aggradation and widespread peat initiation in the Ishikari lowland (northern Japan)

The Holocene ◽  
2016 ◽  
Vol 26 (12) ◽  
pp. 1924-1938 ◽  
Author(s):  
Yuji Ishii ◽  
Kazuaki Hori ◽  
Arata Momohara ◽  
Toshimichi Nakanishi ◽  
Wan Hong
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Climate Changes ◽  
Asian Summer Monsoon ◽  
Sedimentary Environment ◽  
New Approach ◽  
Sea Level Fluctuations ◽  
Asian Summer ◽  
Fluvial Sedimentation ◽  
Northern Japan

This study investigated the influence of sea-level and climate changes on the decreased fluvial aggradation and subsequent widespread peat initiation in the middle to late-Holocene in the Ishikari lowland, which is a coastal floodplain formed in response to the postglacial sea-level change. By introducing a new approach to separately evaluate the rates of organic and clastic sediment input, we demonstrated that the peat began to form when the fluvial sedimentation rate was significantly decreased (less than 0.6 mm/yr), while plant macrofossil analysis suggested that lowering of water level is also important to the peat initiation. Such changes in sedimentary environment may be associated with the abrupt abandonment of crevasse splays. The concentrated ages of the peat initiation around 5600–5000, 4600–4300, and 4100–3600 cal. BP suggest that an allogenic control promoted the abandonment of crevasse splays, and different onset ages can be explained by different fluvial responses of the Ishikari River and its tributaries. The abandonment of crevasse splays could result from sea-level fall or decreased precipitation. While submillennial sea-level fluctuations coincident with the peat initiation have not been reported in coastal lowlands of Japan, the close comparison of the onset ages and decreased precipitation recorded in a stalagmite from China, which represents the strength of the East Asian summer monsoon (EASM), suggests that decrease in precipitation led to the abandonment of crevasse splays. Our results may indicate that similar fluvial responses might be common in other coastal floodplains affected by the EASM.

Periodically forced self-organization in the long-term evolution of planktic foraminifera

2001 ◽  
Vol 38 (2) ◽  
pp. 293-308 ◽  
Author(s):  
Andreas Prokoph ◽  
Anthony D Fowler ◽  
R Timothy Patterson
Keyword(s):  
Sea Level ◽  
Logistic Map ◽  
Late Eocene ◽  
Self Organization ◽  
Extinction Data ◽  
Sea Level Fluctuations ◽  
Global Sea Level ◽  
Extinction Events ◽  
The Impact

Wavelet transform and other signal analysis techniques suggest that the planktic foraminiferal (PF) long-term evolutionary record of the last 127 Ma can be attributed to complex periodic and nonlinear patterns. Correlation of the PF extinction pattern with other geological series favors an origin of the ~30 Ma periodicity and self-organization by quasi-periodic mantle-plume cycles that in turn drive episodic volcanism, CO2-degassing, oceanic anoxic conditions, and sea-level fluctuations. Stationary ~30 Ma periodicity and a weak secular trend of ~100 Ma period are evident in the PF record, even without consideration of the mass extinction at the K–T boundary. The 27–32 Ma periodicity in the impact crater record and lows in the global sea-level curve, respectively, are ~6.5 Ma and ~2.3 Ma out of phase with PF-extinction data, although major PF-extinction events correspond to the bolide impacts at the K–T boundary and in late Eocene. Another six extinction events correspond to abrupt global sea-level falls between the late Albian and early Oligocene. Self-organization in the PF record is characterized by increased radiation rates after major extinction events and a steady number of baseline species. Our computer model of long-term PF evolution replicates this SO pattern. The model consists of output from the logistic map, which is forced at 30 Ma and 100 Ma frequencies. The model has significant correlations with the relative PF-extinction data. In particular, it replicates singularities, such as the K–T event, nonstationary 2.5–10 Ma periodicities, and phase shifts in the ~30 Ma periodicity of the PF record.

scholarly journals Reconstruction of the depositional sedimentary environment of Oligocene deposits (Qom Formation) in the Qom Basin (northern Tethyan seaway), Iran

Geologos ◽  
2020 ◽  
Vol 26 (2) ◽  
pp. 93-111
Author(s):  
Amrollah Safari ◽  
Hossein Ghanbarloo ◽  
Parisa Mansoury ◽  
Mehran Mohammadian Esfahani
Keyword(s):  
Sea Level ◽  
Sedimentary Environment ◽  
Depositional Environments ◽  
Sea Level Changes ◽  
Third Order ◽  
Depositional Sequences ◽  
Qom Formation ◽  
Tethyan Seaway ◽  
Qom Basin ◽  
Global Sea Level

AbstractDuring the Rupelian–Chattian, the Qom Basin (northern seaway basin) was located between the Paratethys in the north and the southern Tethyan seaway in the south. The Oligocene deposits (Qom Formation) in the Qom Basin have been interpreted for a reconstruction of environmental conditions during deposition, as well as of the influence of local fault activities and global sea level changes expressed within the basin. We have also investigated connections between the Qom Basin and adjacent basins. Seven microfacies types have been distinguished in the former. These microfacies formed within three major depositional environments, i.e., restricted lagoon, open lagoon and open marine. Strata of the Qom Formation are suggested to have been formed in an open-shelf system. In addition, the deepening and shallowing patterns noted within the microfacies suggest the presence of three third-order sequences in the Bijegan area and two third-order depositional sequences and an incomplete depositional sequence in the Naragh area. Our analysis suggests that, during the Rupelian and Chattian stages, the depositional sequences of the Qom Basin were influenced primarily by local tectonics, while global sea level changes had a greater impact on the southern Tethyan seaway and Paratethys basins. The depositional basins of the Tethyan seaway (southern Tethyan seaway, Paratethys Basin and Qom Basin) were probably related during the Burdigalian to Langhian and early Serravallian.

Sedimentary evolution of a Late Pleistocene temperate red algal reef (Coralligène) on Rhodes, Greece: correlation with global sea-level fluctuations

Sedimentology ◽  
2008 ◽  
Vol 55 (6) ◽  
pp. 1747-1776 ◽  
Author(s):  
JÜRGEN TITSCHACK ◽  
CAMPBELL S. NELSON ◽  
TIM BECK ◽  
ANDRÉ FREIWALD ◽  
ULRICH RADTKE
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Sea Level Fluctuations ◽  
Sedimentary Evolution ◽  
Red Algal ◽  
Global Sea Level ◽  
Algal Reef

scholarly journals Dominant Role of Sea Level on the Sedimentary Environmental Evolution in the Bohai and Yellow Seas Over the Last 1 Million Years

2021 ◽  
Vol 9 ◽  
Author(s):  
Xuefa Shi ◽  
Zhengquan Yao ◽  
Jianxing Liu ◽  
Shuqing Qiao ◽  
Yanguang Liu ◽  
...  
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
Yellow Sea ◽  
Bohai Sea ◽  
Dominant Role ◽  
Sedimentary Environment ◽  
Middle Pleistocene ◽  
Southern Yellow Sea ◽  
Sea Level Fluctuations ◽  
The Southern Yellow Sea

Transgression and regression deposits from the shallow continental margin provide information on orbital-scale variations in sea level, climate change, and local tectonics. In this study, we conduct a high-resolution chronological and sedimentological analysis of a 125-m core (NHH01) drilled in the southern Yellow Sea. We developed a high-resolution age model at the orbital timescale over the last ∼1 Myr by the astronomical tuning of the sediment grain size. Sedimentological analysis and environmental proxies reveal that the study area is characterized by cyclic alternations of neritic and littoral/fluvial deposits controlled by glacial–interglacial sea-level changes. These results confirm the earlier assumption that sea-level fluctuations play a dominant role in the sedimentary architecture of the southern Yellow Sea. Moreover, only low-frequency sea-level fluctuations (∼100 kyr) were preserved in the NHH01 sequence; however, additional high-frequency (∼40 kyr) sea-level variations were also present in the sediments of the shallower Bohai Sea. Despite the large spatial difference, this finding implies that the sedimentary environment in the eastern marginal seas of China had been influenced by the sea level as a whole over the last 1 Myr. The comparison of the sedimentary environment with other cores from the Bohai Sea, Yellow Sea, and coastal region, as well as records from Indonesia and Japan, reveals that a consistent initiation of large-scale marine transgression occurred at ∼0.8–1 Ma. This phenomenon was likely caused by the long duration of glacio-eustatic high sea-level stands following the Middle Pleistocene transition, which is characterized by a shift in glacial cycles from 40 to 100 kyr.

ACCUMULATIVE COASTS AS RELIABLE INDICATORS OF THE KINEMATICS OF THE SEA LEVEL DURING THE HOLOCENE

2017 ◽  
Author(s):  
Nikolay Dunaev ◽  
Nikolay Dunaev ◽  
Tatiana Repkina ◽  
Tatiana Repkina
Keyword(s):  
Sea Level ◽  
Coastal Zone ◽  
Synoptic Scale ◽  
The Holocene ◽  
Single View ◽  
Sea Level Fluctuations ◽  
Current State ◽  
Geological Section ◽  
Global Sea Level ◽  
Different Parts

Currently, there is no single view of the Holocene global sea level kinematics. At the same time, the question of a possibility of it exceeding the current sea level by several meters is be-ing debated. The accumulative coasts of nearly tide-free seas, in areas where the vertical di-rection of coastal movement remained unchanged are the most convenient objects for study-ing this major paleogeographic issue. Effects of the sea level fluctuations are revealed in the resulting geomorphological structure and in the nature of sediment areas of the coastal zone developing in an accumulative mode. If the Holocene sea level exceeds its modern marks, then ladders of accumulative terraces would have formed over different parts of the coast. The heights of the terrace ladders would correspond to the amplitudes of these exceedances. The lower sediment levels should reflect the transgressive character of their formation in the structure of geological section, while the higher levels would reflect the regressions. The coast of the Thatcher Peninsula, located in the Bay of Cumberland microcontinent of the South Georgia (Antarctic) was the focus of our research. It was established that the Holo-cene sea level in the region reached its current state no later than about one thousand years ago and did not exceed it, being subjected to only minor fluctuations of the synoptic scale. The accumulative terraces are located in fragments. The differences in their absolute eleva-tions are related to their correspondence to different tectonic units experiencing differenti-ated uplift.

ACCUMULATIVE COASTS AS RELIABLE INDICATORS OF THE KINEMATICS OF THE SEA LEVEL DURING THE HOLOCENE

2017 ◽  
Author(s):  
Nikolay Dunaev ◽  
Nikolay Dunaev ◽  
Tatiana Repkina ◽  
Tatiana Repkina
Keyword(s):  
Sea Level ◽  
Coastal Zone ◽  
Synoptic Scale ◽  
The Holocene ◽  
Single View ◽  
Sea Level Fluctuations ◽  
Current State ◽  
Geological Section ◽  
Global Sea Level ◽  
Different Parts

Currently, there is no single view of the Holocene global sea level kinematics. At the same time, the question of a possibility of it exceeding the current sea level by several meters is be-ing debated. The accumulative coasts of nearly tide-free seas, in areas where the vertical di-rection of coastal movement remained unchanged are the most convenient objects for study-ing this major paleogeographic issue. Effects of the sea level fluctuations are revealed in the resulting geomorphological structure and in the nature of sediment areas of the coastal zone developing in an accumulative mode. If the Holocene sea level exceeds its modern marks, then ladders of accumulative terraces would have formed over different parts of the coast. The heights of the terrace ladders would correspond to the amplitudes of these exceedances. The lower sediment levels should reflect the transgressive character of their formation in the structure of geological section, while the higher levels would reflect the regressions. The coast of the Thatcher Peninsula, located in the Bay of Cumberland microcontinent of the South Georgia (Antarctic) was the focus of our research. It was established that the Holo-cene sea level in the region reached its current state no later than about one thousand years ago and did not exceed it, being subjected to only minor fluctuations of the synoptic scale. The accumulative terraces are located in fragments. The differences in their absolute eleva-tions are related to their correspondence to different tectonic units experiencing differenti-ated uplift.

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 Paleozoic–Mesozoic Eustatic Changes and Mass Extinctions: New Insights from Event Interpretation

Life ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 281
Author(s):  
Dmitry A. Ruban
Keyword(s):  
Sea Level ◽  
Late Cretaceous ◽  
Mass Extinction ◽  
Early Jurassic ◽  
Late Devonian ◽  
Mass Extinctions ◽  
Sea Level Changes ◽  
Event Interpretation ◽  
Marine Realm ◽  
Global Sea Level

Recent eustatic reconstructions allow for reconsidering the relationships between the fifteen Paleozoic–Mesozoic mass extinctions (mid-Cambrian, end-Ordovician, Llandovery/Wenlock, Late Devonian, Devonian/Carboniferous, mid-Carboniferous, end-Guadalupian, end-Permian, two mid-Triassic, end-Triassic, Early Jurassic, Jurassic/Cretaceous, Late Cretaceous, and end-Cretaceous extinctions) and global sea-level changes. The relationships between eustatic rises/falls and period-long eustatic trends are examined. Many eustatic events at the mass extinction intervals were not anomalous. Nonetheless, the majority of the considered mass extinctions coincided with either interruptions or changes in the ongoing eustatic trends. It cannot be excluded that such interruptions and changes could have facilitated or even triggered biodiversity losses in the marine realm.

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