Pollen Analysis of a Late-Glacial and Holocene Sediment Core from Mono Lake, Mono County, California

1999 ◽  
Vol 52 (2) ◽  
pp. 243-249 ◽  
Author(s):  
Owen K. Davis
Keyword(s):  
Pollen Analysis ◽  
Vegetation Change ◽  
Late Glacial ◽  
Mono Lake ◽  
Early Holocene ◽  
Summer Drought ◽  
Lake Levels ◽  
Radiocarbon Dates ◽  
Spring Runoff ◽  
Late Glacial And Holocene

Pollen analysis of a 752-cm core from Mono Lake, Mono County, California indicates generally high lake levels 11,600–7000 14C yr B.P., moderate lake levels until ca. 4000 14C yr B.P., and fluctuating levels to the present. Drying events, with lake levels near or below the historic minimum are dated ca. 8800, 4000, 2400, and 1100 14C yr B.P. Chronologic control is provided by six radiocarbon dates and six volcanic ashes. The rate of upland vegetation change is greatest 11,000, 4000, and 1130 14C yr B.P. Juniperus and Sequoaidendron pollen declines 11,000 yr B.P., marking the transition from late-glacial juniper woodland to Holocene steppe. High values (5–20%) of Sequoaidendron pollen are unique to this study and may indicate the presence of these trees east of the Sierra crest. The pollen-based reconstructions of climate are generally cooler and wetter than today, with relatively dry but cool climate during the early Holocene. The contrast between higher lake levels and more arid vegetation during the early Holocene can be explained by insolation-driven seasonality. Greater summer insolation produced summer drought, but lower winter insolation led to greater snowpack, greater spring runoff, and higher lake levels. Increased Artemisia and other Compositae pollen percentages mark the establishment of modern vegetation ca. 2000 14C yr B.P. During the late Holocene, the pollen-based reconstructions of climate generally match the Mono Lake fluctuations proposed by Stine (1990), but fewer fluctuations are recorded.

Radiocarbon Reservoir Effect and the Timing of the Late-Glacial/Early Holocene Humid Phase in the Atacama Desert (Northern Chile)

1999 ◽  
Vol 52 (2) ◽  
pp. 143-153 ◽  
Author(s):  
Mebus A. Geyh ◽  
Martin Grosjean ◽  
Lautaro Núñez ◽  
Ulrich Schotterer
Keyword(s):  
Lake Level ◽  
Atacama Desert ◽  
Late Glacial ◽  
Early Holocene ◽  
Vegetation Changes ◽  
Northern Chile ◽  
Lake Levels ◽  
Human Occupation ◽  
Radiocarbon Dates ◽  
History Of

We revise substantially the regional chronology of lake-level fluctuations from the late-glacial/early Holocene humid phase along a high altitude transect (3500 to 4500 m) between 18°S and 28°S in the Southwestern Altiplano of Northern Chile. Radiocarbon dates and 210Pb profiles for limnic and terrestrial materials allow us to estimate and justify reservoir correction values for conventional 14C dates. Our chronology suggests that the latest Pleistocene/early Holocene humid phase started between 13,000 and 12,000 14C yr B.P., and that maximum lake levels were reached between 10,800 and 9200 14C yr B.P. This is significantly younger than what has been established so far for the Titicaca–Uyuni Basin in Bolivia. The paleolakes disappeared sometime between 8400 and 8000 14C yr B.P. Our revised chronology agrees with the regional history of human occupation, and is broadly synchronous with vegetation changes in subtropical continental South America, and with the onset of wetland expansion in the northern hemisphere tropics.

scholarly journals Late Glacial and Holocene plant cover in Węgliny, Lubsza Plain, south-west Poland, based on pollen analysis

2013 ◽  
Vol 53 (2) ◽  
pp. 191-233 ◽  
Author(s):  
Aleksandra Jurochnik ◽  
Dorota Nalepka
Keyword(s):  
Pollen Analysis ◽  
Plant Cover ◽  
Late Glacial ◽  
Anaerobic Sediments ◽  
The North ◽  
South West ◽  
Pollen Diagrams ◽  
Laacher See Tephra ◽  
Late Glacial And Holocene

ABSTRACT Late Glacial (since Oldest Dryas) and Holocene (to Subatlantic) changes of vegetation at the Węgliny site (south-west Poland) are reconstructed based mainly on pollen analysis of five cores from the palaeobasin (anaerobic sediments). The chronology of the described events is based on palynological comparison with the Lubsza Plain environs, based on LPAZs from several published pollen diagrams on 14C data, and multiple cryptotephra levels determined in the Węgliny profiles. The Węgliny record integrates well into the north European Holocene and Late Glacial biostratigraphic framework. The Węgliny site is the next (fourth) locality in Poland where the Laacher See Tephra (LST) horizon within the Allerød chronozone was identified.

Fine laminated clastic deposits revealing the delay of the deglaciation timing in the High Tatras Mts. (Central Europe) to Early Holocene

2020 ◽  
Author(s):  
Dhavamani Ramachandran ◽  
Radovan Pipík ◽  
Timea Chamutiová ◽  
Lucia Žatková ◽  
Marina Vidhya ◽  
...  
Keyword(s):  
Central Europe ◽  
Late Glacial ◽  
Early Holocene ◽  
Age Dating ◽  
Tatra Mountains ◽  
East Central Europe ◽  
Tatra Mts ◽  
Cosmogenic Nuclide Dating ◽  
Late Glacial And Holocene ◽  
The Tatra Mountains

<p>The Tatra moraine relief and cosmogenic nuclide dating show glacier stabilizationand the maximum glacier extent in two phases,at26 – 21 ka and at 18 ka followed by a gradual retreat and  a termination of the glaciation during the Bølling/Allerød warming at 14.64 –12.9 ka (Makos etal., 2014). A renewed glaciation within the Younger Dryas (12.9 – 11.5 ka) formed smaller rock glaciers. This retreat was connected with the formation of the morainic, trough and cirque lakes and the beginning of light-grey silt sedimentation dated from 10ka to 16ka cal BP on the northern slopes of the Tatra Mountains and before 10ka cal BP on its southern slopes (Klapyta et al., 2016).</p><p>A new paleolimnic research led to a discovery of a cyclic fine laminated deposit in the four Tatra Mts. lakes. The laminae of thickness from 1 to 3 mm are built of couplets of light-coloured coarse detrital and fine dark-coloured laminae. Thicker light coloured laminae occasionally show a gradation ending in dark-coloured laminae. Laminae consist occasionally of low spherical angular grains of sand and gravel fractions, rarely up to size 10 mm which deformed underlying laminae. Light-coloured laminae are predominantly composed of quartz, followed by K-feldspar, plagioclase, mica, and clay-like particles. Dark-coloured laminae consist of clay-size clastic particles. These laminae were formed in cold, oxygen-rich, ultra-oligotrophic, slightly acid conditions in which the chironomids Pseudodiamesa nivosa and Micropsectra radialis-type dominated. We interpret these lamination as varves related to annual glacial melting. Once the valleys were ice-free, varve production stopped and a short deposition period of homogenous silt was replaced by gyttja. The radiometric C<sup>14</sup> age dating shows the deglaciation in the Tatra Mts terminated at the beginning of the Early Holocene, around 10ka cal BP – 9ka cal BP.</p><p> </p><p>The research was funded by APVV-15-0292 and the project Centre of Excellence for Integrated Research of the Earth's Geosphere, ITMS 26220120064.</p><p> </p><p>Klapyta P., Zasadni J., Pociask-Karteczka J., Gajda A., Franczak P., 2016. Late Glacial and Holocene Paleoenvironmental records in the Tatra Mountains, East-Central Europe, based on lake, peat bog and colluvial sedimentary data: A summary review. Quaternary International 415: 126-144.</p><p> </p><p>Makos M., Dzierzek J., Nitychoruk J., Zreda M., 2014. Timing of glacier advances and climate in the Tatra Mountains (Western Carpathians) during the Last Glacial Maximum. Quaternary Research 82: 1-13.</p>

scholarly journals Late glacial and early Holocene hydroclimate variability in northwest Iran (Talesh Mountains) inferred from chironomid and pollen analysis

2017 ◽  
Vol 58 (2) ◽  
pp. 151-167 ◽  
Author(s):  
Cyril Aubert ◽  
Elodie Brisset ◽  
Morteza Djamali ◽  
Arash Sharifi ◽  
Philippe Ponel ◽  
...  
Keyword(s):  
Pollen Analysis ◽  
Late Glacial ◽  
Early Holocene ◽  
Hydroclimate Variability ◽  
Northwest Iran

scholarly journals Radiocarbon Chronology of the Late Pleistocene–Holocene Paleogeographic Events in Lake Baikal Region (Siberia)

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 745-754 ◽  
Author(s):  
Sergey K Krivonogov ◽  
Hikaru Takahara ◽  
Yaroslav V Kuzmin ◽  
Lyobov A Orlova ◽  
A J Timothy Jull ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Lake Baikal ◽  
Baikal Region ◽  
Late Glacial ◽  
Vegetation Changes ◽  
Radiocarbon Dates ◽  
Lake Baikal Region ◽  
Cold Events ◽  
Late Glacial And Holocene ◽  
Radiocarbon Chronology

New radiocarbon dates obtained from Late Pleistocene and Holocene deposits of the southern, eastern, and northern shores of Lake Baikal in 1995–2001 are presented, and the most important results of paleoenvironmental studies based on C data are discussed. The following paleogeographic events were verified with the help of C dating: 1) first Late Pleistocene glaciation (Early Zyryan); 2) Middle Zyryan interstadial; 3) loess formation during the Late Zyryan (Sartan) deglaciation; 4) warm and cold events in the Late Glacial; and 5) vegetation changes and forest successions during the Late Glacial and Holocene.

Hydrological Changes After the Last Ice Retreat in Northern Poland Using Radiocarbon Dating

Radiocarbon ◽  
2013 ◽  
Vol 55 (3) ◽  
pp. 1712-1723 ◽  
Author(s):  
Danuta J Michczyńska ◽  
Leszek Starkel ◽  
Dorota Nalepka ◽  
Anna Pazdur
Keyword(s):  
Radiocarbon Dating ◽  
Late Glacial ◽  
Simplified Model ◽  
Peat Bogs ◽  
Ice Melting ◽  
Radiocarbon Dates ◽  
Hydrological Changes ◽  
Ice Retreat ◽  
Late Glacial And Holocene ◽  
The Last Glacial

A simplified model of hydrological changes during the Late Glacial and Holocene is presented for the northern Polish regions that were ice covered during the Last Glacial. This reconstruction is based on a group of 197 radiocarbon dates from about 120 localities reflecting the sequence of alternating lake transgressions and regressions. The earliest transgressions were related to dead-ice melting (sometimes in 2–3 phases), while the later ones started during more humid phases. However, these were usually followed by regressions, which may have been connected with the formation of new drainage systems and with the overgrowing of shallow lakes by peat bogs.

Stratigraphic relationships and paleoecology of a late-glacial peat bed from the Queen Charlotte Islands, British Columbia

1982 ◽  
Vol 19 (6) ◽  
pp. 1185-1195 ◽  
Author(s):  
Rolf W. Mathewes ◽  
John J. Clague
Keyword(s):  
Late Pleistocene ◽  
Pinus Contorta ◽  
Vegetation History ◽  
Late Glacial ◽  
Plant Macrofossils ◽  
Radiocarbon Dates ◽  
Queen Charlotte Islands ◽  
Modern Analogue ◽  
Armeria Maritima ◽  
Late Glacial And Holocene

The stratigraphic relationships of late-glacial and Holocene sediments exposed in sea cliffs at Cape Ball on the Queen Charlotte Islands are summarized, based on section descriptions and 13 radiocarbon dates on wood, peat, and marine pelecypod shells. One peat bed dated at 12 400 ± 100 years BP (GSC-3112) to 10 200 ± 90 BP (GSC-3159) was investigated for pollen and plant macrofossils. This study extends the late Pleistocene vegetation history of the Queen Charlotte Islands by about 1550 years, and suggests that the record will date back to before 13 700 ± 100 BP (GSC-3222).Four local pollen zones are described from the 70 cm thick peat, beginning with a 7 cm thick herb-dominated zone (CB-1), characterized by up to 60% grass pollen, and including a unique assemblage with abundant Apiaceae, Cyperaceae, Empetrum/Ericaceae, Polemonium, Plantago macrocarpa, Fritillaria, and Ranunculus. A high diversity of other herbs, including subalpine/alpine species and two taxa presently absent from the Charlottes (Armeria maritima and Polemonium caeruleum type), suggests that this zone represents an open floodplain vegetation with no modern analogue. Zone CB-2 (63–45 cm) is dominated by Pinus conforta type pollen (65–70%) and moderate values for fern spores. Zone CB-3 (45–30 cm) shows a rapid rise of Picea pollen from 3 to 39%, followed by a drop to about 12%. Fern spores (20–50%) and Alnus (6%) also reach maximum levels in this zone. Abundant wood fragments and sand inclusions are compatible with an interpretation of a swampy floodplain forest during this interval. The uppermost zone (30–0 cm) exhibits high Pinus contorta (40–60%) and Cyperaceae (12–38%) values, along with a moderate abundance of grasses, ferns, and Apiaceae. Estuarine and marine sediments with pelecypod shells, deposited during a marine transgression, overlie the peat bed.Implications for the controversy over the existence of late Pleistocene refugia in the Charlottes are briefly discussed.

Sign in / Sign up

Export Citation Format

Share Document