Do Stable Isotope Data from Calcrete Record Late Pleistocene Monsoonal Climate Variation in the Thar Desert of India?

1998 ◽  
Vol 50 (3) ◽  
pp. 240-251 ◽  
Author(s):  
Julian E. Andrews ◽  
Ashok K. Singhvi ◽  
Ansu J. Kailath ◽  
Ralph Kuhn ◽  
Paul F. Dennis ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Indian Subcontinent ◽  
Green Light ◽  
Summer Rainfall ◽  
Climatic Conditions ◽  
Thar Desert ◽  
Quaternary Sediments ◽  
Low Latitudes ◽  
Stable Oxygen ◽  
Glacial Periods

Late Pleistocene terrestrial climate records in India may be preserved in oxygen and carbon stable isotopes in pedogenic calcrete. Petrography shows that calcrete nodules in Quaternary sediments of the Thar Desert in Rajasthan are pedogenic, with little evidence for postpedogenic alteration. The calcrete occurs in four laterally persistent and one nonpersistent eolian units, separated by colluvial gravel. Thermoluminescence and infrared- and green-light-stimulated luminescence of host quartz and feldspar grains gave age brackets for persistent eolian units I–IV of ca. 70,000–60,000, ca. 60,000–55,000, ca. 55,000–43,000, and ca. 43,000–∼25,000 yr, respectively. The youngest eolian unit (V) is <10,000 yr old and contains no calcrete. Stable oxygen isotope compositions of calcretes in most of eolian unit I, in the upper part of eolian unit IV, and in the nonpersistent eolian unit, range between −4.6 and −2.1‰ PDB. These values, up to 4.4‰ greater than values from eolian units II and III, are interpreted as representing nonmonsoonal18O-enriched “normal continental” waters during climatic phases when the monsoon weakened or failed. Conversely, 25,000–60,000-yr-old calcretes (eolian units II and III) probably formed under monsoonal conditions. The two periods of weakened monsoon are consistent with other paleoclimatic data from India and may represent widespread aridity on the Indian subcontinent during isotope stages 2 and 4. The total variation in δ13C is 1.7‰ (0.0–1.7‰), and δ13C covaries positively and linearly with δ18O. δ13C values are highest when δ18O values indicate the most arid climatic conditions. This is best explained by expansion of C4grasses at the expense of C3plants at low latitudes during glacial periods when atmospheric pCO2was lowered. C4dominance was overridingly influenced by global change in atmospheric pCO2despite the lowered summer rainfall.

Late Proterozoic glacial carbonates in northeast Spitsbergen: new insights into the carbonate–tillite association

1989 ◽  
Vol 126 (5) ◽  
pp. 469-490 ◽  
Author(s):  
I. J. Fairchild ◽  
M. J. Hambrey ◽  
B. Spiro ◽  
T. H. Jefferson
Keyword(s):  
Oxygen Isotope ◽  
Climatic Conditions ◽  
Source Rocks ◽  
Sedimentary Environments ◽  
Excess Surface ◽  
Low Latitudes ◽  
Glacial Periods ◽  
Mn Concentration ◽  
Detrital Carbonate ◽  
Mn Concentrations

AbstractCarbonate-rich glacial deposits from two discrete Vendian glacial periods are described. The older is represented by the 24–40 m thick Petrovbreen Member (E2) of the Elbobreen Formation which contains abundant detrital dolomite. Clasts in E2 and their possible source rocks have positive δ13C and negative δ18OPDBvalues. In contrast the carbonate mud-fraction of E2 sediments has different cathodoluminescence characteristics from clasts, slightly negative δ13C values, and higher Fe and Mn concentrations than clasts. Oxygen isotopes vary from −2.5 to +4.5‰PDB, thought to be related to various seawater–meltwater mixtures in the depositional environment. Preservation of information about glacial sedimentary environments is attributed to early diagenetic recrystallization forced by excess surface free energy (Ostwald's ripening) and coinciding with sulphate reduction.The younger glaciation is represented by the Wilsonbreen Formation (170 m) which has a distinctive glaciolacustrine Middle Carbonate Member (W2). W2 contains precipitated periglacial carbonates (with high Mn/Fe ratio): both limestone (rhythmitic and stromatolitic) and dolostone (rhythmites, stromatolites and dolomite-rich sandstones) which are compared with carbonates in modern Antarctic lakes. Evaporitic environments for dolomitic sandstones and stromatolitic dolostones are indicated by heavy oxygen isotope values (up to + 10.5‰PDB), high Na concentration and evidence for dissolved evaporites. High Mn concentration in detrital dolostones in W2 is suggestive of syn-sedimentary dolomite recrystallization in freshwater diamictites and haematitic siltstones.The carbonate–tillite association ultimately arises from the erosion of underlying carbonates which originated (in this case) under radically different climatic conditions. Glacial depositional waters then became carbonate-saturated as a result of dissolution of detrital carbonate. Massive recrystallization of glacially transported carbonate is proposed as a geologically significant process with considerable potential for palaeoenvironmental analysis. In glacial lakes carbonate precipitated in response to evaporation or photosynthesis. Carbonate precipitation as the result of seawater freezing, or in warm interglacial conditions, is not yet established. Oxygen isotope value are inconsistent (too heavy) with the presence of high-latitude meltwaters, implying that glaciation extended to low latitudes as proposed by Harland.

scholarly journals Reconstructing Late Pleistocene paleoclimate at the scale of human behavior: an example from the Neandertal occupation of La Ferrassie (France)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Pederzani ◽  
Vera Aldeias ◽  
Harold L. Dibble ◽  
Paul Goldberg ◽  
Jean-Jacques Hublin ◽  
...  
Keyword(s):  
Human Behavior ◽  
Late Pleistocene ◽  
Tooth Enamel ◽  
Climatic Conditions ◽  
Climatic Data ◽  
Human Scale ◽  
Winter Temperatures ◽  
Archaeological Materials ◽  
Climatic Records

AbstractExploring the role of changing climates in human evolution is currently impeded by a scarcity of climatic information at the same temporal scale as the human behaviors documented in archaeological sites. This is mainly caused by high uncertainties in the chronometric dates used to correlate long-term climatic records with archaeological deposits. One solution is to generate climatic data directly from archaeological materials representing human behavior. Here we use oxygen isotope measurements of Bos/Bison tooth enamel to reconstruct summer and winter temperatures in the Late Pleistocene when Neandertals were using the site of La Ferrassie. Our results indicate that, despite the generally cold conditions of the broader period and despite direct evidence for cold features in certain sediments at the site, Neandertals used the site predominantly when climatic conditions were mild, similar to conditions in modern day France. We suggest that due to millennial scale climate variability, the periods of human activity and their climatic characteristics may not be representative of average conditions inferred from chronological correlations with long-term climatic records. These results highlight the importance of using direct routes, such as the high-resolution archives in tooth enamel from anthropogenically accumulated faunal assemblages, to establish climatic conditions at a human scale.

Spodoptera frugiperda (fall armyworm).

2021 ◽  
Author(s):  
Ivan Rwomushana
Keyword(s):  
Spodoptera Frugiperda ◽  
Host Plants ◽  
Indian Subcontinent ◽  
Fall Armyworm ◽  
Climatic Conditions ◽  
Vegetable Crops ◽  
Large Numbers ◽  
Significant Damage ◽  
Lepidopteran Pest ◽  
The Ideal

Abstract The fall armyworm, Spodoptera frugiperda, is a lepidopteran pest that feeds in large numbers on the leaves, stems and reproductive parts of more than 350 plant species, causing major damage to economically important cultivated grasses such as maize, rice, sorghum, sugarcane and wheat but also other vegetable crops and cotton. Native to the Americas, it has been repeatedly intercepted at quarantine in Europe and was first reported from Africa in 2016 where it caused significant damage to maize crops. In 2018, S. frugiperda was first reported from the Indian subcontinent (Ganiger et al., 2018; Sharanabasappa Kalleshwaraswamy et al., 2018). It has since invaded Bangladesh, Thailand, Myanmar, China and Sri Lanka (IPPC, 2018b, 2019; FAO, 2019c). The ideal climatic conditions for fall armyworm present in many parts of Africa and Asia, and the abundance of suitable host plants suggests the pest can produce several generations in a single season, and is likely to lead to the pest becoming endemic.

Late-Glacial Cooling in Amazonia Inferred from Pollen at Lagoa do Caçó, Northern Brazil

2001 ◽  
Vol 55 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Marie-Pierre Ledru ◽  
Renato Campello Cordeiro ◽  
José Maria Landim Dominguez ◽  
Louis Martin ◽  
Philippe Mourguiart ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Ice Core ◽  
Late Glacial ◽  
Climatic Conditions ◽  
Convective Precipitation ◽  
Pollen Data ◽  
Moisture Source ◽  
Northern Latitudes ◽  
Low Latitudes ◽  
Northern Brazil

AbstractNew pollen data from a core at Lagoa do Caçó, Maranhão state, Brazil (2°58′S 43°25′W; 120 m elevation), show higher frequencies of Podocarpus at the end of the Pleistocene than today. The increase in Podocarpus, which follows the successive increase of various pioneer species such as Didymopanax, Melastomataceae/Combretaceae, and Cecropia, implies a progressive late-glacial increase of moist and cool climatic conditions. A comparable increase in Podocarpus is found in other lowland records in Amazonia. A review of published pollen data from Amazonia suggests that the moisture source was from the southeast. By contrast, present-day moisture comes from the tropical Atlantic and from the Amazon basin, with its convective precipitation. The likely cause for the southeastern moisture source between ca. 15,000 and 14,500 cal yr B.P. was enhanced polar (Antarctic) advection that reached low latitudes and maintained year-round the meteorological equator in its austral-winter position at northern latitudes or reduced drastically its southward summer displacement. This hypothesis is consistent with marine and ice core records.

scholarly journals Klimazeugen des periglazialen Dauerfrostbodens in Mittel- und Westeuropa: Ein Beitrag zur Rekonstruktion des Klimas der Glaziale des quartären Eiszeitalters

1960 ◽  
Vol 11 (1) ◽  
pp. 121-141 ◽  
Author(s):  
Karlheinz Kaiser
Keyword(s):  
Western Europe ◽  
Younger Dryas ◽  
Climatic Conditions ◽  
Border Zone ◽  
Patterned Ground ◽  
A Value ◽  
Outer Appearance ◽  
Glacial Periods ◽  
Glacial Time ◽  
Temperature Depression

Abstract. Certain periglacial phenomena (ice-wedges, cryoturbations, patterned ground, pingos) are critically investigated with respect to their outer appearance as well as to the causes of their formation, but especially how far they might be used as indicators of an old permafrost. The results for Central and Western Europe have been mapped according to our actual status of knowledge. The attempts hitherto made to reconstruct the climate of the Quaternary glacial periods, have been thoroughly checked. A new calculation of the maximum diminution of Pleistocene temperature gives a value of 15—16° C (bottom temperature) in Central and Western Europe. For the Younger Dryas we still have to expect a temperature depression of 11—12° C. Both values have been found by comparing mean annual temperatures in the border-zone of permafrost at the high-glacial time and during the Younger Dryas with the actual temperatures. This is true on the premise that the active permafrost area can be limited by the — 2° C annual isotherme, both under actual as well as under glacial climatic conditions.

scholarly journals Palynological profile and depositional environment of the Ishim formation (upper Miocene) in Tobol-Ishim interfluve, Western Siberia

2019 ◽  
Vol 27 (6) ◽  
pp. 103-123
Author(s):  
O. B. Kuzmina ◽  
I. V. Khazina ◽  
P. V. Smirnov ◽  
A. O. Konstantinov ◽  
A. R. Agatova
Keyword(s):  
Late Pleistocene ◽  
Organic Substance ◽  
Late Miocene ◽  
Depositional Environment ◽  
Western Siberia ◽  
Ice Age ◽  
Quaternary Sediments ◽  
Upper Miocene ◽  
Neogene Sediments ◽  
First Time

For the first time some outcrops of the Upper Miocene Ishim Formation on the south of Tyumen Area near Pyatkovo, Masali and Bigila villages are studied by palynological method in detail. A series of mineralogical analyzes of these sediments and radiocarbon analysis of the Quaternary sediments overlying the Ishim Formation are done. Four palynocomplexes (PC) are established in the Ishim Formation: PC1 with Botryococcus; PC2 with Botryococcus, Sigmopollis; PC3 with Alnus, Polypodiaceae, Botryococcus, Sigmopollis; PC4 with Betula, Alnus, Corylus. The layers with PC1, PC2 и PC3 are traced in two outcrops near Masali and Bigila Villages. PC4 is revealed from the sands and aleuropelits of the outcrop near Pyatkovo Village, it is characterized by a significant content of diverse pollen of temperate termophylic broad-leafed taxa and by the presence of rare typical Miocene elements (Таxodiaceae, Nyssa, Tsuga). The PC3 and PC4 are compared with the complexes well known from the Neogene sediments of Western Siberia. PC5 with Betula, Herbae, Fungi is revealed from the bedded silts overlying the Ishim Formation in Masali outcrop. Previously, these sediments were attributed to the Late Miocene Pavlodar Formation. The composition and the structure of PC5 allowed making an assumption about Quaternary age of the enclosing sediments. Radiocarbon analysis of the organic substance from the silts showed, that these sediments were accumulated in the Late Pleistocene (Sartan Ice Age). For the first time the information about microphytoplankton (Botryococcus, Pediastrum, Zygnemataceae, Sigmopollis) and other nonpollen palynomorphs, contained in Ishim Formation (Upper Miocene) and in Pleistocene sediments, is given. On palynological data, some stages of development of the Late Miocene Ishim Basin and the type of vegetation surrounding this basin are considered. The depositional environment of Pleistocene sediments (Masali outcrop) is reconstructed.

Microlithic occurrences associated with sediments dated to terminal Pleistocene-late Holocene in the central Narmada basin, Madhya Pradesh, India

2021 ◽  
pp. SP515-2020-216
Author(s):  
Nupur Tiwari ◽  
P. Morthekai ◽  
K. Krishnan ◽  
Parth R. Chauhan
Keyword(s):  
Sri Lanka ◽  
South Asia ◽  
Late Pleistocene ◽  
Iron Age ◽  
Late Holocene ◽  
Indian Subcontinent ◽  
Central India ◽  
Madhya Pradesh ◽  
Doctoral Research ◽  
Terminal Pleistocene

AbstractThe earliest occurrence of microliths in South Asia dates back to the Late Pleistocene at Mehtakheri (45 ka) and Dhaba (48 ka) in Central India, Jwalapuram 9 in Southern India (38 ka), Kana and Mahadebbara in Northeastern India (42-25 ka) and Batadomba-Lena (35-36 ka) and Fa Hien Lena (48 ka) in Sri Lanka. Microlithic technology is distributed across the entire Indian Subcontinent and chronologically continues up to the Iron Age and Early Historic periods. This paper discusses new data acquired from the first author's doctoral research in the two districts of Madhya Pradesh (Hoshangabad and Sehore), which fall within the central part of the Narmada Basin in central India. We present here the preliminary dates from key areas of distribution to understand the geo-chronological contexts of microliths at Pilikarar, Morpani, and Gurla-Sukkarwada. Initial dates from these respective occurrences range between 12.5 ka and 2.3 ka.

scholarly journals Palaeoecology of giraffe tracks in Late Pleistocene aeolianites on the Cape south coast

2018 ◽  
Vol 114 (1/2) ◽  
Author(s):  
Charles Helm ◽  
Hayley Cawthra ◽  
Richard Cowling ◽  
Jan De Vynck ◽  
Curtis Marean ◽  
...  
Keyword(s):  
South Africa ◽  
Late Pleistocene ◽  
Coastal Plain ◽  
Suitable Habitat ◽  
Geological Evidence ◽  
Pleistocene Climate ◽  
Show Evidence ◽  
Fossil Records ◽  
Glacial Periods ◽  
Still Bay

Until now there have been no reliable historical or skeletal fossil records for the giraffe (Giraffa camelopardalis) south of the Orange River or northern Namaqualand. The recent discovery of fossil giraffe tracks in coastal aeolianites east of Still Bay, South Africa, significantly increases the geographical range for this species, and has implications for Late Pleistocene climate and vegetation in the southern Cape. Giraffe populations have specialised needs, and require a savanna ecosystem. Marine geophysical and geological evidence suggests that the broad, currently submerged floodplains of the Gouritz and Breede Rivers likely supported a productive savanna of Vachellia karroo during Pleistocene glacial conditions, which would have provided a suitable habitat for this species. We show evidence for the hypothesis that the opening of the submerged shelf during glacial periods acted as a pathway for mammals to migrate along the southern coastal plain.

Vipera berus (Linnaeus, 1758) remains from the Late Pleistocene of Slovakia

2017 ◽  
Vol 38 (2) ◽  
pp. 133-144 ◽  
Author(s):  
Martin Ivanov ◽  
Andrej Čerňanský
Keyword(s):  
Late Pleistocene ◽  
Mixed Forest ◽  
Axial Skeleton ◽  
Species Group ◽  
Climatic Conditions ◽  
Mammalian Fauna ◽  
Humid Climate ◽  
Vipera Berus ◽  
Faunal Assemblages ◽  
The Common

Completely preserved specimens of fossil snakes are extremely rare and ophidian palaeontologists are usually dependent only on disarticulated elements of a postcranial skeleton. Here we present an unusually well-preserved specimen of a small viperid snake from the Late Pleistocene firm travertine at the famous Gánovce-Hrádok Neanderthal mound in Slovakia. The complex study of both cranial and axial skeleton with well-preserved maxilla and basiparasphenoid confirms the presence of a viper from theVipera berusspecies group, and recent distribution ofV. berusspecies complex members supports identification of these preserved remains as belonging to the common adder,V. berus(Linnaeus, 1758). Associated faunal assemblages of the MFG-C and D mammalian fauna groups reported from the firm travertine indicate a humid climate in a predominantly woodland environment with typical forest species in the Gánovce-Hrádok vicinity throughout the Eemian optimum, and mixed forest and steppe environments in the late Eemian to early Weichselian stages. Occurrence ofV. berusdocuments the presence of open or semi-open biotopes with low vegetation. AlthoughV. berusoccurs in the Quaternary glacial/interglacial cycle and throughout the entire warm part, it never dominated herpetofaunal assemblages during the climatic optimum. Therefore, the presence ofV. berusmost likely indicates late Eemian or early Weichselian (interstadial) climatic conditions.

scholarly journals Evidence from the Rio Bayo valley on the extent of the North Patagonian Icefield during the Late Pleistocene–Holocene Transition

2006 ◽  
Vol 65 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Neil F. Glasser ◽  
Stephan Harrison ◽  
Susan Ivy-Ochs ◽  
Geoffrey A.T. Duller ◽  
Peter W. Kubik
Keyword(s):  
Late Pleistocene ◽  
Climatic Conditions ◽  
Optically Stimulated Luminescence ◽  
Luminescence Dating ◽  
Age Dating ◽  
Outlet Glacier ◽  
Geomorphological Mapping ◽  
Cosmogenic Nuclide ◽  
The North ◽  
Exposure Age

AbstractThis paper presents data on the extent of the North Patagonian Icefield during the Late Pleistocene–Holocene transition using cosmogenic nuclide exposure age and optically stimulated luminescence dating. We describe geomorphological and geochronological evidence for glacier extent in one of the major valleys surrounding the North Patagonian Icefield, the Rio Bayo valley. Geomorphological mapping provides evidence for the existence of two types of former ice masses in this area: (i) a large outlet glacier of the North Patagonian Icefield, which occupied the main Rio Bayo valley, and (ii) a number of small glaciers that developed in cirques on the slopes of the mountains surrounding the valley. Cosmogenic nuclide exposure-age dating of two erratic boulders on the floor of the Rio Bayo valley indicate that the outlet glacier of the icefield withdrew from the Rio Bayo valley after 10,900 ± 1000 yr (the mean of two boulders dated to 11,400 ± 900 yr and 10,500 ± 800 yr). Single-grain optically stimulated luminescence (OSL) dating of an ice-contact landform constructed against this glacier indicates that this ice mass remained in the valley until at least 9700 ± 700 yr. The agreement between the two independent dating techniques (OSL and cosmogenic nuclide exposure age dating) increases our confidence in these age estimates. A date obtained from a boulder on a cirque moraine above the main valley indicates that glaciers advanced in cirques surrounding the icefield some time around 12,500 ± 900 yr. This evidence for an expanded North Patagonian Icefield between 10,900 ± 1000 yr and 9700 ± 700 yr implies cold climatic conditions dominated at this time.

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