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.

Indications of Holocene sea-level rise in Beaver Lake, East Antarctica

2007 ◽  
Vol 19 (1) ◽  
pp. 125-128 ◽  
Author(s):  
Bernd Wagner ◽  
Nadja Hultzsch ◽  
Martin Melles ◽  
Damian B. Gore
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
East Antarctica ◽  
Relative Sea Level ◽  
The Holocene ◽  
Isostatic Uplift ◽  
Beaver Lake ◽  
Holocene Sea Level

A 100 cm long sediment sequence was recovered from Beaver Lake in Amery Oasis, East Antarctica, using gravity and piston corers. Sedimentological and mineralogical analyses and the absence of micro and macrofossils indicate that the sediments at the base of the sequence formed under glacial conditions, probably prior to c. 12 500 cal. yr BP. The sediments between c. 81 and 31 cm depth probably formed under subaerial conditions, indicating that isostatic uplift since deglaciation has been substantially less than eustatic sea-level rise and that large areas of the present-day floor of Beaver Lake must have been subaerially exposed following deglaciation. The upper 31 cm of the sediment sequence were deposited under glaciomarine conditions similar to those of today, supporting geomorphic observations that the Holocene was a period of relative sea-level highstand in Amery Oasis.

scholarly journals Geomorphology of Canyon Outlets in Zrmanja River Estuary and Its Effect on the Holocene Flooding of Semi-enclosed Basins (the Novigrad and Karin Seas, Eastern Adriatic)

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2807
Author(s):  
Ozren Hasan ◽  
Slobodan Miko ◽  
Dea Brunović ◽  
George Papatheodorou ◽  
Dimitris Christodolou ◽  
...  
Keyword(s):  
High Resolution ◽  
Sea Level Rise ◽  
Sea Level ◽  
Geophysical Methods ◽  
River Estuary ◽  
Side Scan Sonar ◽  
The Holocene ◽  
Karst Environment ◽  
Gis Environment ◽  
Holocene Sea Level

Detailed multi-beam bathymetry, sub-bottom acoustic, and side-scan sonar observations of submerged canyons with tufa barriers were used to characterize the Zrmanja River karst estuary on the eastern Adriatic coast, Croatia. This unique karst environment consists of two submerged karst basins (Novigrad Sea and Karin Sea) that are connected with river canyons named Novsko Ždrilo and Karinsko Ždrilo. The combined use of high-resolution geophysical data with legacy topography and bathymetry data in a GIS environment allowed for the description and interpretation of this geomorphological setting in relation to the Holocene sea-level rise. The tufa barriers had a predominant influence on the Holocene flooding dynamics of the canyons and karst basins. Here, we describe the possible river pathways from the basins during the lowstand and the formation of a lengthening estuary during the Holocene sea-level rise. Based on the analyzed morphologies and the relative sea-level curve for the Adriatic Sea, the flooding of the Novsko Ždrilo occurred 9200 years before present (BP) and Karinsko Ždrilo was flooded after 8400 years BP. The combination of high-resolution geophysical methods gave an accurate representation of the karst estuarine seafloor and the flooding of semi-isolated basins due to sea-level rise.

scholarly journals Holocene sea-level change and estuary infill in North West Nelson, central New Zealand

The Holocene ◽  
2021 ◽  
pp. 095968362110604
Author(s):  
David M Kennedy ◽  
Beth V Risdon ◽  
Josephine LD Woods
Keyword(s):  
New Zealand ◽  
Sea Level ◽  
Central Basin ◽  
Marine Transgression ◽  
The Holocene ◽  
North West ◽  
Sedimentary Sequences ◽  
The North ◽  
History Of ◽  
Holocene Sea Level

The sedimentary sequences found within estuaries in the north west Nelson region of central New Zealand are investigated in order to quantify the timing of the end of the Post Glacial Marine Transgression. This region has been identified as being relatively stable in terms of vertical tectonic movement during the Holocene, but is yet to yield any reconstructions of eustatic sea level. In this study, we investigate the Holocene infill of a barrier estuary (Parapara Inlet) through sedimentological analysis and radiocarbon dating of 18 vibracores up to 4.2 m in length. It is found that the estuary infilled through a combination of lateral flood tide and fluvial delta progradation as well as vertical central basin infill. The central basin infilled at a consistent rate of 0.4 mm/year in both the mid (7.0–6.0 ka) and late-Holocene (2.5–1.5 ka). By the time of early human (Maori) settlement (c. 1 ka), the estuary surface was at low intertidal elevations with sediment being transported from the fluvial to tidal delta. A discernible change in sedimentation rates could not be associated with Maori settlement; however, infill rates increased to at least 12.5 mm/year in the past 150 years due hydraulic sluicing associated with mining. The sedimentary history of Parapara Inlet is compared to nearby Whanganui Inlet, d’Urville Island and Nelson to establish the character of regional Holocene sea level movement. It is found that relative sea level reached modern elevations between 8 and 7 ka in the region. The similarity between sea level curves for the end of the post glacial marine transgression (PMT) to other tectonically stable sites in northern New Zealand suggests that this curve can now be considered a true eustatic signal for the New Zealand archipelago.

scholarly journals Holocene sedimentation offshore Southeast Vietnam based on geophysical interpretation and sediment composition analysis

2021 ◽  
Vol 43 (3) ◽  
Author(s):  
Long Hoang Van ◽  
Thanh Nguyen Tien ◽  
Tuan Vu Tat ◽  
Tung Nguyen Thanh ◽  
Anh Nguyen Lam ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
High Energy ◽  
Heavy Minerals ◽  
Energy Conditions ◽  
Composition Analysis ◽  
The Holocene ◽  
Sedimentary Evolution ◽  
New Findings ◽  
Holocene Sea Level

Offshore Southeast (SE) Vietnam is considered a transition zone, with the sedimentary evolution of this area controlled by land-sea interactions, especially by the Holocene sea-level rise. This study presents some new findings regarding Holocene sedimentation and its linkage to the heavy mineral placers within the study area based on high-resolution seismic interpretation and sediment analysis. Our obtained results show that the Holocene sediments directly overlie the Late Pleistocene sedimentary formation, from which they are separated by an erosional/unconformity surface (R­1­ seismic reflector). Sediments deposited in the Early (~11.7-8.2kyr BP), Middle-Late (8.2kyr BP-present-day) Holocene sub-epochs correspond to the Transgressive and Highstand System tracts, which were closely controlled by the three stages of Holocene sea-level rise. The recent sediments distributed on the seafloor are dominated by sand and gravelly sand, demonstrating high-energy conditions, while the heavy minerals are rich in ilmenite and zircon. Most of these are concentrated along the present shoreline zones, but we do not exclude their accumulation in the paleo-shoreline and incised channels. Two ilmenite dispersion halos (1st and 2nd order) and one zircon dispersion halo (1st order) suggest that ilmenite and zircon are the most dominant heavy minerals while gold is only observed locally. The minerals were potentially derived from the weathering products of the Triassic-Cretaceous ilmenite-, zircon-, and gold-bearing granite and granitoid in central Vietnam.

Late Holocene relative sea level rise and the Neoglacial history of the Greenland ice sheet

2009 ◽  
Vol 24 (4) ◽  
pp. 345-359 ◽  
Author(s):  
Antony J. Long ◽  
Sarah A. Woodroffe ◽  
Sue Dawson ◽  
David H. Roberts ◽  
Charlotte L. Bryant
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Late Holocene ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Relative Sea Level ◽  
Relative Sea Level Rise ◽  
History Of

Influences of Relative Sea-Level Rise and Mississippi River Delta Plain Evolution on the Holocene Middle Amite River, Southeastern Louisiana

1993 ◽  
Vol 39 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Whitney J. Autin
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Mississippi River ◽  
Drainage Basin ◽  
River Delta ◽  
Mississippi River Delta ◽  
Relative Sea Level ◽  
The Holocene ◽  
Delta Plain ◽  
Relative Sea Level Rise

AbstractThe Holocene geomorphic history of southeastern Louisiana's middle Amite River is recorded in the stratigraphy of three alloformations, identified in decreasing age as the Watson (WAT), Denham Springs (DS), and Magnolia Bridge (MAG). The WAT meander belt formed by at least 9000 yr B.P., when sea level was lower and the Amite River was tributary to a larger ancestral drainage basin. The DS became an active meander belt by at least 3000 yr B.P., in response to relative sea-level rise and eastward progradation of the Mississippi River delta plain. The MAG developed its meander belt, in part, during the European settlement of the drainage basin, and is now attempting to adjust to modern anthropogenic influences. Geomorphic influences on the middle Amite River floodplain have temporal and spatial components that induce regional- and local-scale effects. Regional extrinsic influences caused meander belt avulsion that produced alloformations. However, local influences produced intrinsic geomorphic thresholds that modified channel morphology within a meander belt but did not induce alloformation development. Base-level influences of the relative sea-level rise and the Mississippi River delta plain were so dominant that the effects of possible climate change were not recognized in the Holocene Amite River system.

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