scholarly journals Foraminiferal record of changes in summer monsoon precipitation at the Southeastern Brazilian continental margin since the Last Glacial Maximum

2010 ◽  
Vol 13 (2) ◽  
pp. 79-88 ◽  
Author(s):  
María Alejandra Pivel ◽  
Felipe Toledo ◽  
Karen Costa
Keyword(s):  
Last Glacial Maximum ◽  
Summer Monsoon ◽  
Continental Margin ◽  
Glacial Maximum ◽  
Monsoon Precipitation ◽  
Last Glacial ◽  
Foraminiferal Record ◽  
The Last Glacial Maximum ◽  
The Last Glacial

10Be data from meltwater channels suggest that Jameson Land, east Greenland, was ice-covered during the last glacial maximum

2011 ◽  
Vol 76 (3) ◽  
pp. 452-459 ◽  
Author(s):  
Lena Håkansson ◽  
Jason P. Briner ◽  
Ala Aldahan ◽  
Göran Possnert
Keyword(s):  
Last Glacial Maximum ◽  
Continental Margin ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Last Glaciation ◽  
Exposure Age ◽  
Bedrock Weathering ◽  
The Mean ◽  
The Last Glacial Maximum ◽  
The Last Glacial

AbstractAlong the northeast Greenland continental margin, bedrock on interfjord plateaus is highly weathered, whereas rock surfaces in fjord troughs are characterized by glacial scour. Based on the intense bedrock weathering and lack of glacial deposits from the last glaciation, interfjord plateaus have long been thought to be ice-free throughout the last glacial maximum (LGM). In recent years there is growing evidence from shelf and fjord settings that the northeast Greenland continental margin was more extensively glaciated during the LGM than previously thought. However, little is still known from interfjord settings. We present cosmogenic 10Be data from meltwater channels and weathered sandstone outcrops on Jameson Land, an interfjord highland north of Scoresby Sund. The mean exposure age of samples from channel beds (n = 3) constrains on the onset of deglaciation on interior Jameson Land to 18.5 ± 1.3–21.4 ± 1.9 ka (for erosion conditions of 0–10 mm/ka, respectively). This finding adds to growing evidence that the northeast Greenland continental margin was more heavily glaciated during the LGM than previously thought.

Reconstructions of the past distribution of Testudo graeca mitochondrial lineages in the Middle East and Transcaucasia support multiple refugia since the Last Glacial Maximum

2021 ◽  
pp. 10-17
Author(s):  
Oguz Turkozan
Keyword(s):  
Middle East ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Testudo Graeca ◽  
Last Glacial ◽  
The Past ◽  
Precipitation Seasonality ◽  
Multiple Refugia ◽  
The Last Glacial Maximum ◽  
The Last Glacial

A cycle of glacial and interglacial periods in the Quaternary caused species’ ranges to expand and contract in response to climatic and environmental changes. During interglacial periods, many species expanded their distribution ranges from refugia into higher elevations and latitudes. In the present work, we projected the responses of the five lineages of Testudo graeca in the Middle East and Transcaucasia as the climate shifted from the Last Glacial Maximum (LGM, Mid – Holocene), to the present. Under the past LGM and Mid-Holocene bioclimatic conditions, models predicted relatively more suitable habitats for some of the lineages. The most significant bioclimatic variables in predicting the present and past potential distribution of clades are the precipitation of the warmest quarter for T. g. armeniaca (95.8 %), precipitation seasonality for T. g. buxtoni (85.0 %), minimum temperature of the coldest month for T. g. ibera (75.4 %), precipitation of the coldest quarter for T. g. terrestris (34.1 %), and the mean temperature of the driest quarter for T. g. zarudyni (88.8 %). Since the LGM, we hypothesise that the ranges of lineages have either expanded (T. g. ibera), contracted (T. g. zarudnyi) or remained stable (T. g. terrestris), and for other two taxa (T. g. armeniaca and T. g. buxtoni) the pattern remains unclear. Our analysis predicts multiple refugia for Testudo during the LGM and supports previous hypotheses about high lineage richness in Anatolia resulting from secondary contact.

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