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.

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 Global sea-level control on local parasequence architecture from the Holocene record of the Po Plain, Italy

2017 ◽  
Vol 87 ◽  
pp. 99-111 ◽  
Author(s):  
Alessandro Amorosi ◽  
Luigi Bruno ◽  
Bruno Campo ◽  
Agnese Morelli ◽  
Veronica Rossi ◽  
...  
Keyword(s):  
Sea Level ◽  
Level Control ◽  
Po Plain ◽  
The Holocene ◽  
Holocene Record ◽  
Global Sea Level

Holocene sea-level history of the Canadian Beaufort shelf

1993 ◽  
Vol 30 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Philip R. Hill ◽  
Arnaud Héquette ◽  
Marie-Hélène Ruz
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Zone ◽  
Marine Sediments ◽  
Tidal Marsh ◽  
Relative Sea Level ◽  
The Holocene ◽  
Single Piece ◽  
History Of ◽  
Holocene Sea Level

New radiocarbon ages pertaining to the Holocene sea-level history of the Canadian Beaufort shelf are presented. The ages were obtained on samples of freshwater and tidal-marsh peat beds from offshore boreholes and shallow cores in the coastal zone and on molluscs and a single piece of wood deposited in foraminifera-bearing marine sediments. Although none of the samples record directly the position of relative sea level, the suite of ages constrains the regional curve sufficiently to suggest a faster rate of mid Holocene sea level rise (7–14 mm/a) than previously thought. The rate of relative rise slowed markedly in the last 3000 years, approaching the present at a maximum probable rate of 2.5 mm/a.

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 Post-glacial Foraminifera of the incised Yangtze paleo-valley and paleoenvironmental implications

2017 ◽  
Vol 91 (6) ◽  
pp. 1102-1122 ◽  
Author(s):  
Xue Ke ◽  
Baohua Li ◽  
Zongyan Zhang ◽  
Yi Wei ◽  
Fei Hu ◽  
...  
Keyword(s):  
Sea Level ◽  
Middle Part ◽  
The Other ◽  
Glacial Deposit ◽  
Benthic Foraminifers ◽  
The Holocene ◽  
Middle Holocene ◽  
Sea Level Fluctuations ◽  
The Core ◽  
Abundance And Diversity

AbstractThree gravity cores (LZK1, ZKA4, and CSJA6) from the incised Yangtze paleo-valley comprise a thick sequence of the post-glacial deposit. Nineteen genera (26 species) of the benthic foraminifers are described from these cores, with detailed down-core foraminiferal variations to investigate their paleoenvironmental implications. Three foraminiferal assemblages are recognized for the lower, middle, and upper parts of the cores respectively. The lower part is dominated byAmmonia beccariivar. andFlorilus decoruswith lower abundance and diversity. In the middle part, the foraminifers are abundant and diverse, dominated by bothAmmonia beccariivar. andElphidium advenum.Cavarotalia annectens,Pararotalia nipponica, and porcellaneous benthic foraminiferal forms are always present, sometimes abundant. The upper part is characterized by theAmmonia beccarii-Elphidium magellanicumassemblage, except for the Core ZKA4, which is barren of foraminifers in this interval. AMS14C dates and foraminiferal assemblages both confirm that the transgression-regression sequence in these cores belongs to the “Ammoniatransgression” during the Holocene. In addition to documenting the post-glacial sea-level fluctuations, the benthic foraminifers also reflect a warmer climate during the early–middle Holocene. The foraminiferal differences among the three cores can be used to interpret the influence of seawater during the post-glacial sea-level fluctuations. The area in the vicinity of Core ZKA4 was affected by marine water only during the middle Holocene, which was much shorter than the areas of the other cores.

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