scholarly journals A Late Middle Pleistocene Climatic Cycle in Southern Italy Inferred From Pollen Analysis and Tephrostratigraphy of the Acerno Lacustrine Succession

2002 ◽  
Vol 55 (1) ◽  
pp. 87-99 ◽  
Author(s):  
Rosalba Munno ◽  
Paola Petrosino ◽  
Paola Romano ◽  
Elda Russo Ermolli ◽  
Étienne Juvigné

Abstract The Acerno lacustrine basin represents a tectonic palaeolake formed in the southern Apennines during the Middle Pleistocene. Pollen analysis performed on the lacustrine sequence (about 100 m thick) allows the vegetation history to be reconstructed and correlated with a late Middle Pleistocene interglacial-glacial cycle. Interglacial conditions are evidenced by a rich oak forest phase while the glacial period is highlighted by a sharp decrease in all arboreal taxa and by the contemporaneous increase in herbaceous and steppe elements. The absence of subtropical elements such as cf. Taxodium and Carya throughout the sequence suggests a late Middle Pleistocene age on the basis of comparison with the nearby Vallo di Diano palaeolacustrine basin where these elements survived until the end of isotopic stage 13. Analysis of the thickest tephra layers identified throughout the sequence provide further constraints to better define its chronological position which is correlated with isotopic stages 9 and 8 by the presence of the Lower WTT (White Trachytic Tuff) marker level, dated 297 000 yr BP.

2018 ◽  
Vol 90 (1) ◽  
pp. 153-163 ◽  
Author(s):  
Samuel Jonathan Barrett ◽  
Ruth Drescher-Schneider ◽  
Reinhard Starnberger ◽  
Christoph Spötl

AbstractThe pre-last glacial maximum paleolake sediments at Baumkirchen, western Austria, are well known in Alpine Quaternary stratigraphy as being the type locality of the Middle to Upper Würmian transition. Their location provides a rare opportunity to investigate the vegetation history of the interior of the Alps during the last glacial cycle. A recent renewed research effort involving new drilling revealed a 250-m-thick lacustrine sequence with an older, ca. Marine Oxygen Isotope Stage (MIS) 4 phase and a younger, mid- to late MIS 3 phase. Pollen analysis reveals generally poor preservation and very low pollen concentration due to very high sedimentation rates. On the basis of pollen percentages and influx rates, six pollen zones (PZ) were assigned. PZ1 and 2 correspond to the entire ca. MIS 4 section and are characterized by only scattered vegetation representing an extremely cold and dry climate. Two stadials and two interstadials were identified in the MIS 3 section. The interstadials are characterized by well-developed open vegetation with some stands of trees, with the upper PZ6 being better developed but still forest-free. On the basis of previous radiocarbon dating, this zone (PZ6) is correlated to Greenland Interstadial (GI) 7 and the lower interstadial (PZ4) tentatively to GI 8.


2017 ◽  
Vol 68 (1) ◽  
pp. 43-56 ◽  
Author(s):  
Nicoletta Santangelo ◽  
Paola Romano ◽  
Alessandra Ascione ◽  
Elda Russo Ermolli

AbstractThe Quaternary evolution of the main coastal basins located along the southwestern margin of the Southern Apennines has been reconstructed by integrating the huge amount of existing stratigraphical and geomorphological data. The information produced in the last twenty years has shed new light on the recent (late Middle Pleistocene to Present) history of the Campanian and Sele plains or basins. During the early Quaternary, the analysed coastal basins originated as half-grabens in response to opening processes active since the late Tortonian in the southern Tyrrhenian back-arc basin. In some of these basins (e.g. the Campanian Plain), volcanism has also played an important role. In the inner sectors of the coastal basins, the complex interplay between block faulting, sedimentary inputs and glacioeustatic fluctuations gave rise to relative sea-level change and related coastline migrations, leading to the formation of the present-day coastal plains. In the Sele Plain basin, the construction of the present-day landscape mainly resulted from the substantial ceasing of subsidence in the final part of the Middle Pleistocene. Conversely, a strong contribution to the recent evolution of the Campanian Plain has been provided by abundant volcaniclastic aggradation, able to hinder the effect of the vertical motions that occurred in the last 100 ka.


2021 ◽  
Vol 13 (9) ◽  
pp. 4848
Author(s):  
Liwei Wu ◽  
Xinling Li ◽  
Qinghai Xu ◽  
Manyue Li ◽  
Qiufeng Zheng ◽  
...  

The East Asian monsoon system is an important part of global atmospheric circulation; however, records of the East Asian monsoon from different regions exhibit different evolutionary rhythms. Here, we show a high-resolution record of grain size and pollen data from a lacustrine sediment core of Dajiuhu Lake in Shennongjia, Hubei Province, China, in order to reconstruct the paleovegetation and paleoeclimate evolution of the Dajiuhu Basin since the late Middle Pleistocene (~237.9 ka to the present). The results show that grain size and pollen record of the core DJH-2 are consistent with the δ18O record of stalagmites from Sanbao Cave in the same area, which is closely related to the changes of insolation at the precessional (~20-kyr) scale in the Northern Hemisphere. This is different from the records of the Asian summer monsoon recorded in the Loess Plateau of North China, which exhibited dominant 100-kyr change cyclicities. We suggest that the difference between paleoclimatic records from North and South China is closely related to the east–west-oriented mountain ranges of the Qinling Mountains in central China that blocked weakened East Asia summer monsoons across the mountains during glacial periods.


Author(s):  
Philip L. Gibbard ◽  
Mark D. Bateman ◽  
Jane Leathard ◽  
R.G. West

Abstract Previous investigation of isolated landforms, on the eastern margin of the East Anglian Fenland, England, has demonstrated that they represent an ice-marginal delta and alluvial fan complex deposited at the margin of an ice lobe that entered the Fenland during the ‘Tottenhill glaciation’ (termed the ‘Skertchly Line’). They have been attributed, based on regional correlations, to a glaciation during the Late Wolstonian (i.e. Late Saalian) Substage (Drenthe Stadial, early Marine Isotope Stage (MIS) 6). This paper aimed to test this correlation by directly optically luminescence dating, for the first time, sediments found within the Skertchly Line at Shouldham Thorpe, Norfolk, and Maidscross Hill, Suffolk, together with those in associated kame terrace deposits at Watlington, Norfolk. Ages ranged from 244 ± 10 ka to 12.8 ± 0.46 ka, all the results being younger than MIS 8 with some clearly showing the landforms have been subsequently subjected to periglacial processes, particularly during the Late Devensian Substage (∼MIS 2). Most of the remainder fall within the range 169–212 ka and could be assigned to MIS 6, thus confirming the previously proposed age of the glaciation. The local and regional implications of these conclusions are discussed, the maximum ice limit being linked to that of the Amersfoort–Nijmegen glaciotectonic ridge limit in the central Netherlands.


2017 ◽  
Vol 68 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Marcello Schiattarella ◽  
Salvatore Ivo Giano ◽  
Dario Gioia

Abstract Uplift and erosion rates have been calculated for a large sector of the Campania-Lucania Apennine and Calabrian arc, Italy, using both geomorphological observations (elevations, ages and arrangement of depositional and erosional land surfaces and other morphotectonic markers) and stratigraphical and structural data (sea-level related facies, base levels, fault kinematics, and fault offset estimations). The values of the Quaternary uplift rates of the southern Apennines vary from 0.2 mm/yr to about 1.2–1.3 mm/yr. The erosion rates from key-areas of the southern Apennines, obtained from both quantitative geomorphic analysis and missing volumes calculations, has been estimated at 0.2 mm/yr since the Middle Pleistocene. Since the Late Pleistocene erosion and uplift rates match well, the axial-zone landscape could have reached a flux steady state during that time, although it is more probable that the entire study area may be a transient landscape. Tectonic denudation phenomena — leading to the exhumation of the Mesozoic core of the chain — followed by an impressive regional planation started in the Late Pliocene have to be taken into account for a coherent explanation of the morphological evolution of southern Italy.


2004 ◽  
Vol 359 (1442) ◽  
pp. 173-181 ◽  
Author(s):  
Henry Hooghiemstra ◽  
Thomas Van der Hammen

Pollen records from lacustrine sediments of deep basins in the Colombian Andes provide records of vegetation history, the development of the floristic composition of biomes, and climate variation with increasing temporal resolution. Local differences in the altitudinal distribution of present–day vegetation belts in four Colombian Cordilleras are presented. Operating mechanisms during Quaternary Ice–Age cycles that stimulated speciation are discussed by considering endemism in the asteraceous genera Espeletia , Espeletiopsis and Coespeletia . The floristically diverse lower montane forest belt (1000–2300 m) was compressed by ca . 55% during the last glacial maximum (LGM) (20 ka), and occupied the slopes between 800 m and 1400 m during that period. Under low LGM atmospheric p CO 2 values, C 4 –dominated vegetation, now occurring below 2200 m, expanded up to ca. 3500 m. Present–day C 3 –dominated paramo vegetation is therefore not an analogue for past C 4 –dominated vegetation (with abundant Sporobolus lasiophyllus ). Quercus immigrated into Colombia 478 ka and formed an extensive zonal forest from 330 ka when former Podocarpus –dominated forest was replaced by zonal forest with Quercus and Weinmannia . During the last glacial cycle the ecological tolerance of Quercus may have increased. In the ecotone forests Quercus was rapidly and massively replaced by Polylepis between 45 and 30 ka illustrating complex forest dynamics in the tropical Andes.


Author(s):  
Martin R. Bates ◽  
C. Richard Bates ◽  
Philip L. Gibbard ◽  
Richard I. Macphail ◽  
Frederick J. Owen ◽  
...  

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