Response of the high-resolution Chinese loess grain size record to the 50°N integrated winter insolation during the last 500,000 years

2014 ◽  
Vol 41 (17) ◽  
pp. 6244-6251 ◽  
Author(s):  
Jiasheng Chen ◽  
Xiuming Liu ◽  
Vadim A. Kravchinsky
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Chinese Loess ◽  
Winter Insolation

scholarly journals Paleoenvironments from robust loess stratigraphy using high-resolution color and grain-size data of the last glacial Krems-Wachtberg record (NE Austria)

2020 ◽  
Vol 248 ◽  
pp. 106602
Author(s):  
Tobias Sprafke ◽  
Philipp Schulte ◽  
Simon Meyer-Heintze ◽  
Marc Händel ◽  
Thomas Einwögerer ◽  
...  
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Last Glacial ◽  
Size Data ◽  
The Last Glacial

scholarly journals Rip current evidence by hydrodynamic simulations, bathymetric surveys and UAV observation

2017 ◽  
Author(s):  
Guido Benassai ◽  
Pietro Aucelli ◽  
Giorgio Budillon ◽  
Massimo De Stefano ◽  
Diana Di Luccio ◽  
...  
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Numerical Simulations ◽  
Current System ◽  
Current Evidence ◽  
Rip Current ◽  
Rip Currents ◽  
Transport Pathways ◽  
Fine Sediments ◽  
Scientific Challenge

Abstract. The prediction of the formation, spacing and location of rip currents is a scientific challenge that can be achieved by means of different complementary methods. In this paper the analysis of numerical and experimental data, including UAV observation, allowed to detect the presence of rip currents and rip channels at the mouth of Sele river, in the Gulf of Salerno, southern Italy. The dataset used to analyze these phenomena consisted of two different bathymetric surveys, a detailed sediment 5 analysis and a set of high-resolution wave numerical simulations, completed with satellite and UAV observation. The grain size trend analysis and the numerical simulations allowed to identify the rip current system, forced by topographically constrained channels incised on the seabed, which were detected by high resolution bathymetric surveys. The study evidenced that on the coastal area of the Sele mouth grain-size trends are controlled by the contribution of fine sediments, which exhibit suspended transport pathways due to rip currents and longshore currents. The results obtained were confirmed by satellite and UAV 10 observations in different years.

scholarly journals Periodicities of paleoclimate variations in the first high-resolution non-orbitally tuned grain size record of the past 1 Ma from SW Hungary and regional, global correlations

2019 ◽  
Vol 40 ◽  
pp. 74-90 ◽  
Author(s):  
Pál Sümegi ◽  
Sándor Gulyás ◽  
Dávid Molnár ◽  
Balázs P. Sümegi ◽  
Tünde Törőcsik ◽  
...  
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
The Past

A high-resolution sediment record of East Asian summer monsoon from the northern South China Sea spanning the past 7500 years

The Holocene ◽  
2020 ◽  
Vol 30 (12) ◽  
pp. 1669-1680
Author(s):  
Chao Huang ◽  
Mingkun Li ◽  
Zhifeng Liu ◽  
Gangjian Wei ◽  
Fajin Chen ◽  
...  
Keyword(s):  
Grain Size ◽  
Solar Activity ◽  
High Resolution ◽  
South China Sea ◽  
South China ◽  
East Asian Summer Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Sediment Records ◽  
Asian Summer

High-resolution Holocene marine sediment records are limited, which hampers our understanding of paleomonsoon evolution. Continental shelf sediment records are derived mainly from terrestrial weathering products and are thus often sensitive to paleoclimate variations. In this study, the grain size and magnetic mineral composition of a well-dated sediment core (YJ Core) from the northern inner shelf of the South China Sea (SCS) were analyzed to provide a high-resolution record of the Holocene evolution of the East Asian summer monsoon (EASM). These magnetic and grain size records indicate that EASM intensity followed a general declining trend between approximately 6800 and 2000 cal yr BP. This general pattern is synchronous with other geologic archives from monsoon regions, and can be attributed to solar radiation forcing in the Northern Hemisphere. On centennial timescales, a weak EASM closely coincides with periods of weak solar activity. In addition, spectral analysis of clays reveals five prominent cycles, with periodicities of approximately 364, 202, 158, 119, and 104 years, which correspond to solar activity cycles. The similarities between the cyclicities of the Asian monsoon signal in sedimentary records and those of solar activity demonstrate that solar forcing has a relatively large influence on the centennial-scale variability of the EASM.

High resolution magnetostratigraphy and deposition cycles in the Nihewan Basin (North China) and their significance for stone artifact dating

2008 ◽  
Vol 69 (2) ◽  
pp. 250-262 ◽  
Author(s):  
Li Huamei ◽  
Yang Xiaoqiang ◽  
Friedrich Heller ◽  
Li Haitao
Keyword(s):  
Grain Size ◽  
Age Determination ◽  
Size Fraction ◽  
Close Relation ◽  
Homo Erectus ◽  
Chinese Loess Plateau ◽  
Chinese Loess ◽  
Susceptibility Data ◽  
Nihewan Basin ◽  
Stone Artifact

Three lacustrine sections in the Nihewan Basin, Xiaodukou, Donggutuo and Xiaochangliang (40.1–40.4°N; 114.6–114.7°E), were closely sampled for magnetostratigraphic and deposition cycle analysis. Rock magnetic investigations show that the characteristic remanent magnetization of the sediments is mainly carried by magnetite and hematite. The Xiaodukou sequence is one of the most complete sections in the basin and has recorded substantial parts of the Brunhes and Matuyama chrons back to the termination of the Olduvai subchron. Several subchrons within the Matuyama period have been documented such as the Jaramillo, the Cobb Mt. and others. The Matuyama/Brunhes boundary, the Jaramillo, as well as the Cobb Mountain events were observed also at Donggutuo. On the basis of grain size and susceptibility data and of field investigations, the sections are divided into two longer lasting lacustrine episodes with a fluvio-lacustrine deposit in between. They are structured by 15 high-frequency deposition sub-cycles. In each cycle, the grain size fines upwards, while magnetic susceptibility decreases. This behavior is due to cyclic water level change of the ancient lake Nihewan. At Xiaodukou, the variations of the 0.2 to 7.5 μm grain size fraction can be correlated with the marine oxygen isotope stages OIS 64–OIS 11. The grey-green clayey to silty Paleolithic stone artifact layers at Xiaochangliang and Donggutuo are located at depths of 55.4 m and 43–38.7 m, respectively. They were buried when the lake-level was rising. The artifact layers have been deposited around the Cobb Mountain event during the sedimentary sub-cycle 6 of the older lacustrine phase corresponding to OIS 35, 36. Thus in contrast to the results of other studies, the estimated age of the Xiaochangliang stone artifact layer does not exceed 1.26 Ma, while the Donggutuo stone artifact layers date back to 1.21–1.15 Ma. This age determination brings the Nihewan hominids in close relation to the findings of Homo Erectus at Lantian on the Chinese Loess Plateau.

DETERMINING RESERVOIR CONTINUITY IN THE LAMINARIA FORMATION BY INTEGRATED GEOLOGICAL STUDY

2001 ◽  
Vol 41 (1) ◽  
pp. 415 ◽  
Author(s):  
D.C. Barr ◽  
A.F. Kennaird ◽  
J. Fowles ◽  
N.G. Marshall ◽  
V.L. Cutten
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Sea Level ◽  
Clay Content ◽  
Coarse Grained ◽  
Log Data ◽  
Reservoir Performance ◽  
Subaqueous Dunes ◽  
Reservoir Sandstones ◽  
Reservoir Potential

A recent geological study, integrating sedimentological core-derived descriptions with ichnofacies, high resolution biostratigraphy and wireline log data, establishes the lateral continuity of reservoir sandstones in the Laminaria Formation. By defining a hierarchy of bedding surfaces and correlating this hierarchy with major correlation surfaces, and lateral and vertical facies patterns, it was possible to identify genetically related sediment packages between 12 wells in the study area.The Laminaria Formation is interpreted to have been deposited on a tide and storm-influenced marine shelf, and was strongly influenced by fluctuations in sea level. The formation consists of a series of progradational parasequences, each dominated by good quality, fine- to medium-grained sandstone. These sandstones are believed to have formed as subaqueous dunes or sand banks, exhibiting blanket-like geometry over much of the area. Several sandstones are capped by thin, intraclast-rich layers that mark transgressive surfaces of erosion. These surfaces can be traced across the study area and, therefore, act as important correlative markers.Evidence of gradual transgression, which ultimately led to the drowning of the system, is seen near the top of the formation. Clay content increases upward, while grain size and bedding thickness generally decrease. However, several thin, laterally extensive, medium- to coarse-grained sandstones exist, improving reservoir potential in this part of the formation.The results of this study are being used to estimate reserves and assess reservoir performance, and will serve as a basis for future geological and petrophysical modelling work.

Sign in / Sign up

Export Citation Format

Share Document