Droughts of the Past: Dendrochronology and Lake Sediments

2011 ◽  
pp. 46-67
Keyword(s):  
Lake Sediments ◽  
The Past

Non-pollen Palynomorphs in Freshwater Sediments and their Palaeolimnological Potential and Selected Applications

2020 ◽  
pp. SP511-2020-109
Author(s):  
F. M. C. McCarthy ◽  
P. M. Pilkington ◽  
O. Volik ◽  
A. Heyde ◽  
S. L. Cocker
Keyword(s):  
Lake Sediments ◽  
Freshwater Ecosystems ◽  
Trophic Levels ◽  
Agricultural Activity ◽  
Content Type ◽  
The Past ◽  
Nutrient Influx ◽  
Supplementary Material ◽  
Research Questions ◽  
Processing Techniques

AbstractThe earliest eukaryotes recorded in continental environments are non-pollen palynomorphs (NPP) in Mesoproterozoic strata, and NPP provide our best insights into lacustrine ecosystems through the Paleogene. They have been underexploited in studies of younger lake sediments, either ignored or only qualitatively observed, because many NPP are destroyed by standard processing techniques for pollen and embryophyte spores. The palaeoenvironmental potential of palynomorphs, with representatives from all eukaryotic kingdoms as well as cyanobacteria and from all trophic levels in various lacustrine environments, has been recognized by a few Quaternary palynologists in the past few decades. NPP have proven particularly valuable in archaeological and environmental monitoring studies of human impact on freshwater ecosystems, with spores of some fungi and eggs/ egg cases of some flatworms and roundworms associated with feces of humans and livestock, and the acid-resistant remains of various life stages of cyanobacteria, algae, and their aquatic consumers responding to increased turbidity and nutrient influx associated with permanent human settlements, particularly those associated with agricultural activity. Descriptions of NPP commonly encountered in Quaternary lake sediments and case studies illustrating applications to various research questions should encourage more palynologists that ‘Quaternary non-pollen palynomorphs' deserve our attention!’, to quote Prof. Bas van Geel, undisputed Father of NPP Research.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5244661

A comparison of geomagnetic secular variation as recorded by historical, archaeomagnetic and palaeomagnetic measurements

1982 ◽  
Vol 306 (1492) ◽  
pp. 103-112 ◽  
Keyword(s):  
Magnetic Field ◽  
Lake Sediments ◽  
Secular Variation ◽  
Geomagnetic Field ◽  
Secular Change ◽  
Mathematical Approach ◽  
Geomagnetic Secular Variation ◽  
The Past ◽  
Palaeomagnetic Data ◽  
Field Behaviour

Palaeomagnetic methods can extend the documentary record of changes in the Earth’s magnetic field far into the past. Tolerable agreement is found between various methods, demonstrating the geophysical value of palaeomagnetic experiments. Combining results from the different approaches of investigating secular change can lead to a better perspective and to superior models of geomagnetic field behaviour. Lake sediments have recently been found to hold remarkably detailed signatures of past field changes. A mathematical approach to formulating an empirical description of global geomagnetic field behaviour is proposed and applied to palaeomagnetic data spanning the last 10 ka.

HOLOCENE PALEOENVIRONMENT AND PREHISPANIC LANDSCAPE EVOLUTION IN THE BASIN OF MEXICO

2015 ◽  
Vol 26 (2) ◽  
pp. 375-389 ◽  
Author(s):  
Emily McClung de Tapia
Keyword(s):  
Lake Sediments ◽  
Human Impact ◽  
Human Activity ◽  
Late Holocene ◽  
Landscape Evolution ◽  
Future Research ◽  
Human Adaptation ◽  
The Past ◽  
Basin Of Mexico ◽  
Ecosystem Evolution

AbstractPaleoenvironmental and geoarchaeological data generated over the past three decades for parts of the Basin of Mexico are little known among archaeologists working in the region. This paper summarizes and evaluates what is currently known about the prehistoric environment, landscape development, and human impact in the region. Archaeological evidence indicates that human activity became important in ecosystem evolution in the basin during the Middle-Late Holocene. Most traditional paleoenvironmental studies based on lake sediments, however, generalize results corresponding to this period simply asevidence for human impact. Essentially the same vegetation communities extant in the basin today appear to have been present during most of the Holocene, albeit with broader distributions and variability in secondary taxa. Recognizing potential contributions of archaeology to understanding human adaptation to climatic and ecosystemic change, past and present, should stimulate future research on paleoenvironment in the region.

scholarly journals Lake sediments record large-scale shifts in moisture regimes across the northern prairies of North America during the past two millennia

2003 ◽  
Vol 100 (5) ◽  
pp. 2483-2488 ◽  
Author(s):  
K. R. Laird ◽  
B. F. Cumming ◽  
S. Wunsam ◽  
J. A. Rusak ◽  
R. J. Oglesby ◽  
...  
Keyword(s):  
North America ◽  
Lake Sediments ◽  
Large Scale ◽  
The Past ◽  
Moisture Regimes

A varve-based calibration of the Bridge River tephra fall

1995 ◽  
Vol 32 (12) ◽  
pp. 2098-2102 ◽  
Author(s):  
Eric M. Leonard
Keyword(s):  
Lake Sediments ◽  
Thick Layer ◽  
Tephra Layer ◽  
Tephra Fall ◽  
Radiocarbon Age ◽  
Eruptive Event ◽  
The Core ◽  
The Past ◽  
Ash Layer ◽  
Varved Lake Sediments

A 1 cm thick layer of Bridge River tephra is preserved in a core of varved lake sediments recovered from Hector Lake, Alberta. The varve sequence extends from the core top to well below the tephra layer and has bseen calibrated to calendar years. A varve count yields a calendar age of 2332 BP for the ash layer, with a potential error of about ±50 years. This age is about 30 years younger than the current best radiocarbon-based estimate of the time of the eruption. However, in light of the potential errors in both the varve count and the radiocarbon age, the two ages are not inconsistent. The tephra contains no biotite. In the past, biotite-free Bridge River tephra has been associated with a possible late (ca. 2000 BP) tephra fall, but the tephra from Hector Lake is clearly associated with the main (2300–2400 BP) eruptive event.

scholarly journals Reconstruction of atmospheric soot history in inland regions from lake sediments over the past 150 years

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Y. M. Han ◽  
C. Wei ◽  
R.-J. Huang ◽  
B. A. M. Bandowe ◽  
S. S. H. Ho ◽  
...  
Keyword(s):  
Lake Sediments ◽  
The Past
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