astronomical tuning of long pollen records reveals the dynamic history of montane biomes and lake levels in the tropical high andes during the quaternary long pollen records from two sediment cores of the basin of bogota colombia are presented reflecting the dynamic history of environmental and vegetation changes in the tropical high andes during the quaternary an astronomically tuned age model has been developed by using the visual correlation of the temperature constrained record of alnus with the benthic 18o stacked record of odp site 846 and 849 for the last 1 million year ma in addition spectral analysis of the arboreal pollen percentages ap prior to 1 ma shows two consistent peaks at 7 6 and 9 5 m which could either be interpreted as reflecting the 19 and 23 kyr components of the precession cycle or the 41 kyr cycle of obliquity evidence for precession forcing comes from the sum of the filtered 7 6 and 9 5 m cycles revealing a long term modulation that can be linked to the short term 100 kyr and long term 400 kyr eccentricity cycles a precession forced scenario however is not consistent with zircon fission track ages and is difficult to explain in terms of climate forcing mechanisms on the contrary an obliquity control of the ap record is consistent with the fission track ages and with glacial interglacial bound temperature changes within the study region accordingly it appears that the funza09 record extends back to 2 25 ma during which four periods with distinct different depositional environments could be identified following a chronological poorly constrained interval of fluvial and fluvio lacustrine sediments from 2 25 to 1 47 ma sediment deposition occurred in an area of wetlands dissected by fluvial channels and swamps the strongest subsidence of the basin occurred between 1 47 and 1 23 ma when a proper lake developed lacustrine sediments accumulated in water up to 50 m deep between 1 23 and 0 86 ma hereafter water depth was generally lower than 50 m but fluctuated in conjunction with the 100 kyr dominated glacial interglacial variability during the middle and late pleistocene the evolutionary changes of the paramo and montane forest biomes are described in terms of five characteristic stages most of the pleistocene vegetation has no analogue to modern assemblages principally due to the late immigration events of alnus 1 01 ma and quercus 0 43 ma and we conclude that forest composition similar to modern was not established until the last interglacial however modern ecological constraints of suites of taxa that formed the vegetation of the pre mis 5 part of the record allow a reconstruction of environmental and climate change

rapid subsidence and preservation of fluvial signals in an otherwise wave reworked delta front succession early mid pliocene orinoco continental margin growth se trinidad abstract outcrops of the early mid pliocene orinoco delta succession on the atlantic facing trinidad continental margin demonstrate facies and stratigraphic architecture of a shelf margin developed in a setting of high sediment supply orinoco river and unusually rapid sediment accumulation subsidence averaging 1 km my the studied moruga clastic wedge of the orinoco margin consists of a series of topset to deepwater clinoforms with channelized sandstones river and mixed process delta front wave dominated delta front shoreface prodelta offshore transition shelf upper slope turbidite channels and mass transport deposits the succession is sand prone and generally consists of coarsening and thickening upward delta front lobes with hummocky swaley and wave ripple stratified sandstones indicating dominant storm wave reworking of the delta particularly when the delta lobes had reached outer shelf sites after long shelf transits the lower parts of distributary channels are well preserved and characterized by cross bedded to parallel laminated sandstones with mud clast lags the upper parts of channel fills were wave reworked during transgressions creating hummocky swaley cross stratified strata river dominated and mixed process wave and tide delta front deposits occur commonly within stacked coarsening upward units the river dominated delta front deposits exhibit parallel laminated to current ripple laminated intervals with normally graded thin beds changing upward to parallel and low angle cross lamination but mixed process delta front deposits also contain wave and bidirectional current ripples as well as discrete intervals of hummocky swaley cross stratification the preservation of the channel base as well as river and mixed process delta front deposits in the otherwise storm wave dominated atlantic facing setting suggests some sheltering of the coastal morphology and possibly low frequency of large storms but it is more likely that the unusually rapid subsidence at rates competing well with icehouse rates of eustatic sea level change and burial of deposits may have prevented the fluvial and tidal signals from being completely reworked by the storm waves in the studied outcrop area this study demonstrates an example of how the interactions of river tide and wave generated facies impacted stratigraphic architecture of a rapid subsiding shelf margin built by shelf edge deltas with high sediment supply

a 600 000 year long continental pollen record from lake van eastern anatolia turkey abstract lake van is the fourth largest terminal lake in the world 38 5 n 43 e volume 607 km 3 area 3570 km 2 maximum water depth 460 m extending for 130 km wsw ene on the eastern anatolian high plateau turkey the sedimentary record of lake van partly laminated obtains a long and continuous continental sequence that covers multiple interglacial glacial cycles promoted by the potential of the sedimentary sequence for reconstructing the paleoecological and paleoclimate development of the near east a deep drilling operation was carried out in 2010 supported by the international continental scientific drilling program icdp the 219 m long continental pollen record presented here is based on a well dated composite profile drilled on the so called ahlat ridge in water depth of 360 m encompassing the last 600 000 years it is the longest continuous continental pollen record of the quaternary in the entire near east and central asia obtained to date the glacial interglacial cycles and pronounced interstadials are clearly reflected in the vegetation development based on millennial scale time resolution in general the glacial stadial vegetation is characterized by dwarf shrub steppe and desert steppe whereas the climax vegetation of past interglacials can be described as oak steppe forest similar to the present interglacial in this sensitive semi arid region between the black caspian and mediterranean seas by comparing the lake van pollen record with other western asian and southern european long continental pollen sequences as well as marine and ice core records the regional variability of the climate signals is also discussed

discovery of the first quaternary maar in the bohemian massif central europe based on combined geophysical and geological surveys abstract based on results of previous investigations of tephra tuff volcaniclastic deposits and a geophysical survey in the surroundings of the elezna h rka quaternary volcano west bohemia we performed detailed geophysical surveys using gravimetry magnetometry and electrical conductivity techniques striking anomalies were revealed in a morphological depression near m tina west bohemia as a strong evidence of the assumed maar diatreme structure the sharp isometric gravity low of 2 30 mgal as well as the corresponding positive magnetic anomaly of 200 nt with a negative rim on its northern side indicate a steeply dipping geological body of low density and containing magnetic rocks minerals magnetic survey also showed pronounced local anomalies outside the depression that can reflect relicts of the tephra rim of the maar this geophysical evidence was then proven by an exploratory drilling near the centre of the gravity anomaly macroscopic on site evaluation of the core and more detailed sedimentological petrochemical palynological and microbiological laboratory analyses further confirmed the existence of a maar structure filled by 84 m of lake sediments reflecting a succession of several warm and cold climatic periods results of palynological analyses confirm the presence of a continuous palaeoclimate archive with at least three successive warmer periods of most probably interstadial character from the upper quaternary saalian complex therefore the recovered sediment sequence holds strong potential for in depth paleoclimate reconstruction and deep biosphere studies at the bottom of the m tina 1 my 1 borehole 84 85 5 m country rock debris was found containing also volcanic bombs and lapilli the discovered volcanic structure is considered to be the first known quaternary maar diatreme volcano on the territory of the bohemian massif because of hidden active magmatic processes in combination with earthquake swarm seismicity ca 20 30 km north of the m tina maar reconstruction of the palaeovolcanological evolution is important for evaluation of hazard potential of the ne and e part of the cheb basin

four climate cycles of recurring deep and surface water destabilizations on the iberian margin centennial climate variability over the last ice age exhibits clear bipolar behavior high resolution analyses of marine sediment cores from the iberian margin trace a number of associated changes simultaneously proxies of sea surface temperature and water mass distribution as well as relative biomarker content demonstrate that this typical north south coupling was pervasive for the cold phases of climate during the past 420 000 years cold episodes after relatively warm and largely ice free periods occurred when the predominance of deep water formation changed from northern to southern sources these results reinforce the connection between rapid climate changes at mediterranean latitudes and century to millennial variability in northern and southern polar regions

quaternary geology of eastern germany saxony saxon anhalt south brandenburg thuringia type area of the elsterian and saalian stages in europe abstract the characteristic feature of the quaternary geology of eastern germany location map fig 1 is a sequence of more than 50 horizons and complexes of glacial laminated clays tills glaciofluvial sediments and periglacial river gravels gelifluction sheets alluvium loess facies in the period between the younger tertiary and the first elsterian continental glaciation at least four gravel terraces were built up under cold climate conditions the youngest of these gravel bodies lacks scandinavian rocks and is interbedded with elsterian glaciolacustrine deposits pre elsterian temperate periods have been recorded at a number of places i e zeuchfeld untermassfeld voigtstedt sussenborn two major ice advances with additional minor oscillations have been identified of elsterian and saalian ages complete eemian and holsteinian sequences are represented showing vegetational development through each interglacial cycle cool temperate warm cool the weichselian glacial stage in eastern germany is represented by thick periglacial sedimentation including gravels gelifluction sheets alluvium debris covers and loess within these sediments is a wide variety of glaciotectonic structures and periglacial soil structures including classical involutions and ice wedge casts an outline of the present state of knowledge of the quaternary of eastern germany is given in tables 1 3 while table 4 presents a stratigraphical comparison with the neighbouring regions and countries the palaeogeography of the region during the periods of the european continental glaciation is depicted in fig 2

new evidence for vegetation development and timing of upper middle pleistocene interglacials in northern germany and tentative correlations abstract this paper discusses palynological investigations and new 230th u ages of two upper middle pleistocene sequences of the formerly glaciated northern german lowlands the reinsdorf sequence at the open mine of schoningen lower saxony and the north friesian site of leck new 230th u ages of late interglacial organic layers of the archaeological lake margin site of the reinsdorf sequence ranging from 280 to 343 ka give evidence for a correlation of those deposits with marine isotope stage mis 9 near and long distance correlation by means of palynological investigations of holsteinian and related interglacial continental deposits and their correlation with the mis is discussed isotopic investigations of uranium and thorium from organic rich mud deposits at core leck 8 point to an open system and age estimation by 230th u dating remains therefore unclear compared to other upper middle pleistocene warm periods in north germany correlations of the leck interglacial with the holsteinian and the reinsdorf interglacial can be excluded in comparison with sediment successions from the nachtigall section at hoxter and the section ottostrase at gottingen the leck interglacial is discussed as a correlative of a warm temperate phase of mis 7

a census of mesoscale eddies in shelikof strait alaska during 1989 over a 5 month period in the spring and summer of 1989 12 mesoscale eddies were identified crossing a section of moored current meters in the shelikof sea valley this represents the first census of mesoscale eddies on the northwestern gulf of alaska continental shelf the majority of eddies 7 were observed in may and june anticyclonic eddies outnumbered cyclonic eddies two to one but all had characteristics similar to eddies previously observed in the region analysis of the current meter time series revealed that the mean speeds volume transport and the structure of the flow at the present location were similar to current meter and hydrographic measurements during other years in the sea valley we suggest that 1989 was a typical year in terms of eddy formation as well the proliferation of mesoscale eddies in this region in spring has an impact on the larval dispersal and eventual recruitment of walleye pollock

climatic variability of marine isotope stage 7 direct land sea ice correlation from a multiproxy analysis of a north western iberian margin deep sea core abstract the direct land sea ice correlation performed in the north western iberian margin core md01 2447 shows that marine isotope stage 7 mis 7 is marked by an alternation of five warm and cold periods this climatic variability is in general synchronously detected in marine and terrestrial realms by our record termination iii is marked by three cold episodes the last one interrupts the forest development in north western iberia related to the deglacial climatic amelioration it begins in the middle of termination iii but the maximal cold conditions occur at the beginning of low ice volume conditions mis 7 is characterised by three periods of very low ice volume associated with marine and continental high temperatures in and off north western iberia the correlation of our record with odp site 980 shows that the climatic variability detected in the north western iberian region has also an imprint in northern north atlantic it also highlights that most of the cold periods are associated with iceberg discharges in the north atlantic the comparison of the north western iberian margin sequence with the long european pollen records has allowed refining the correlation of the marine and continental stratigraphy for mis 7

pollen analytical biostratigraphy of the last five climatic cycles from a long continental sequence from the velay region massif central france in the volcanic region of velay massif central france lake sediment sequences derived from maar craters situated close to one another ribains praclaux and lac du bouchet have been correlated on the basis of tephrostratigraphical analyses this has enabled the construction of a sequence 2980 pollen spectra that begins during the glaciation preceding the holsteinian and ends in the present this sequence covers the period from 450 ka i e from the end of marine oxygen isotope stage 12 to the present time and includes five climatic cycles the study of a second core from the praclaux site completed the long velay sequence the biostratigraphy of the whole sequence is described in detail and illustrated by a synthetic and simplified pollen diagram thirteen temperate forest episodes interglacials or interstadials and as many cold periods glacials or stadials are defined each temperate episode is characterised by particular forest development and vegetation dynamics and all of them with the exception of the holocene begin and end with a pinus forest the vegetation dynamics observed during the holocene resemble more closely those recorded during the interstadials than during the interglacials copyright 2000 john wiley sons ltd

integrated geophysical and geological methods to investigate the inner and outer structures of the quaternary mýtina maar w bohemia czech republic the m tina maar is the first known quaternary maar in the bohemian massif based on the results of mrlina et al j volcanol geother res 182 97 112 2009 a multiparametric geophysical electrical resistivity tomography gravimetry magnetometry seismics and geological petrochemical research study had been carried out the interpretation of the data has provided new information about the inner structure of the volcanic complex 1 specification of the depth of post volcanic sedimentary fill up to 100 m and 2 magnetic and resistivity signs of one or two hidden volcanic structures interpreted as intrusions or remains of a scoria cone the findings at the outer structure of the maar incorporate the 1 evidence of circular fracture zones outside the maar 2 detection and distribution of volcanic ejecta and tephra fall deposits at the surface and 3 indications from electrical resistivity tomography and gravity data in the area between the m tina maar and elezna h rka scoria cone interpreted as a palaeovalley filled by volcaniclastic rocks and aligned along the strike line nw se of the tachov fault zone these findings are valuable contributions to extend the knowledge about structure of maar volcanoes in general because of ongoing active magmatic processes in the north east part of the cheb basin ca 15 30 km north of the investigation area the m tina maar diatreme volcano and surroundings is a suitable key area for research directed to reconstruction of the palaeovolcanic evolution and assessment of possible future hazard potential in the bohemian massif

uranium series dating of fen peat horizons from pit nachtigall in northern germany abstract peat and other terrestrial sediments are important archives of climate forcing this study discusses the numerical age determination of stratigraphically important quaternary sequences from clay pit nachtigall near holzminden in northern germany which have been the subject of debate concerning their chronological classification since they were first described by grupe in 1929 uranium series dating 230 th u of different organic horizons as well as sedimentology including loss on ignition loi and palynology was carried out to set up a more reliable chronological framework for the weser river area 230 th u ages were calculated using an isochron approach with the leachate leachate method for chemical preparation open system requirements and specification of sample selection criteria for organic samples are investigated by determination of uranium and thorium composition of the rim layers different organic sediments are investigated the organic deposits from nachtigall show middle pleistocene 230 th u ages ranging from 227 9 8 ka to 201 15 13 ka and appear to represent a warm temperate phase preceding the eemian interglacial mis 5e and the drenthe stadial mis 6 indicating a correlation with marine isotope substage mis 7c these results are in good agreement with the investigation of the pollen spectra indicating a correlation with a warm stage within the lower saalian complex

re interpretation of the meikirch pollen record swiss alpine foreland and implications for middle pleistocene chronostratigraphy the meikirch drilling site in the swiss midlands north of bern is re interpreted using a combination of sedimentological logging pollen analyses and luminescence dating the sedimentary sequence comprises about 70 m of lacustrine deposits overlain by about 39 m of coarse glacial outwash interpreted to represent at least two independent ice advances pollen analyses of the apparently complete limnic sequence reveal a basal late glacial period followed by three warm phases that are interrupted by two stadial periods meikirch complex the warm periods were previously correlated with the holsteinian and eemian interglacials according to luminescence dating and with consideration of evidence for middle pleistocene climate patterns at other central european sites a correlation of the meikirch complex with marine isotope stage mis 7 is now proposed if this correlation is correct it implies the presence of three intervals with interglacial character during mis 7 however the late middle pleistocene vegetational features of the meikirch complex show significant differences when compared with the pollen record from the velay region central france possible explanations for this discrepancy are distinct middle pleistocene patterns of atmospheric circulation over central europe and a different distribution of vegetation refugia compared to the eemian interglacial and the holocene copyright 2005 john wiley sons ltd

nachtigall a continental sediment and pollen sequence of the saalian complex in nw germany and its relationship to the mis framework abstract the nachtigall clay pit near holzminden northern germany is located in a subrosional basin filled with 43 m of interglacial interstadial and stadial deposits adjacent to the weser river the succession separates the older middle terrace from the younger middle terrace of the weser river nachtigall core kb1 1998 mainly contains silt and clay with intercalated peat layers the layers of fen peat and intercalated humic silt are between 36 and 22 5 m depth according to palynological studies the peat layers and some humic silts were deposited during interglacial and interstadial periods marked by forest vegetation termed nachtigall 1 and nachtigall 2 they are subdivided by a stadial termed albaxen the peat of nachtigall 1 is interrupted twice by silt and clay strata allochthonous unit i ii which are reworked sediments of older glacial periods possibly of late elsterian or early holsteinian age the palynological sequences of nachtigall and gottingen ottostrasse show the same pattern moreover the contemporaneous pollen profiles of nachtigall and gottingen ottostrasse can be compared with the velay pollen sequence france the nachtigall core section 36 26 02 m corresponds to bouchet 2 bonnefond bouchet 3 in velay the profiles of velay and nachtigall are independently correlated to the mis timescale and correspond to mis 7c 7b and 7a tims 230th u dating shows ages ranging from 227 9 8 to 201 15 13 ka which are in good agreement with the inferred mis 7 age

climatic conditions during marine oxygen isotope stage 6 in the eastern mediterranean region from the isotopic composition of speleothems of soreq cave israel at several times during marine oxygen isotope stage 6 the eastern mediterranean region was influenced by two extreme climatic systems the large ice sheet over northern europe and the wet tropics associated with african monsoons during this interval two major climatic events occurred in the region the sapropel s6 layer formed ca 176 ka in the eastern mediterranean basin owing to the increase in the african monsoon and another event although not large enough to form sapropel occurred ca 151 ka the isotopic composition of soreq cave speleothems seems to record these events as very low 18 o 13 c values dated as ca 178 and 152 ka the very low 18 o 13 c values of 6 and 11 to 12 respectively are typical of interglacial intervals but here they were recorded during a glacial interval such low peaks indicate that in this part of the eastern mediterranean region i e israel the rainfall amount increased dramatically moreover the isotopic record of the speleothems also shows that during the entire stage 6 although the climate was as cold as much of the last glacial the conditions were never as dry

the beginning of the ice age in europe and its major subdivisions abstract the time range of the quaternary is discussed in terms of the view that this period is essentially the one in the earth s history in which during certain intervals inland ice developed in the northern hemisphere this process first became evident about 2 3 ma bp since then the quaternary thus defined has witnessed many climatic variations although for practical reasons it is not feasible to assign the status of stage to each distinclty warm or cold phase climatic change is nevertheless the most appropriate basis for world wide correlation it seems possible to use both climatic change and other correlation parameters to arrive at a practicable subdivision of the quaternary period into stages before about 1 ma vegetational succession during interglacials in western europe differed from that seen in later times a possible cause for this divergence is discussed in the later part of the quaternary after about 1 ma two distinct types of warm temperate intervals occurred one associated with high sea levels and an oceanic climate the other showing lower sea levels and a cooler and more continental climate the difference between these two types is shown by comparison of the distribution of abies during these time intervals

climatostratigraphy of interglacials in poland middle and upper pleistocene lower boundaries from a polish perspective abstract the brunhes matuyama paleomagnetic boundary has been identified in some key interglacial sites in poland helping in interpret the results of many years climatostratigraphic research the major qualitative stratigraphic boundary is located at the onset of the mazovian interglacial holsteinian that separates the older composite from the younger simple interglacials the two composite interglacials comprise 2 3 interglacial rank warmings each separated by profound but non glacial coolings the four simple interglacials mazovian interglacial included are expressed by single warmings only each interglacial possesses a characteristic pollen succession and the successive interglacials are interbedded with tills of the scandinavian provenance simple interglacials are typical of mis 11 1 and reflect a climate system predominated by 100 ka orbital cycles composite interglacials are characteristic of the interval mis 22 12 and reflect a transition from a climate system predominated by 41 ka orbital cycles to 100 ka cycles i e the mid pleistocene revolution based on these general differences the mis 23 22 and mis 12 11 boundaries are recommended as key thresholds during the pleistocene and could be reconsidered as the lower boundaries of middle and upper pleistocene respectively

a long pollen record from lac du bouchet massif central france for the period ca 325 to 100 ka bp ois 9c to ois 5e abstract pollen analysis was carried out on sediments older than the wurm pleniglacial ois 4 in two new sequences h and i derived from the centre of lac du bouchet massif central the inferred vegetation history enables for the first time in france five temperate episodes to be defined which pre date the last interglacial these temperate episodes alternate with episodes during which the changes in vegetation are indicative of glacial climates comparison of these climatic episodes with the oceanic isotope record shows that the pollen record of sequences h and i from lac du bouchet spans the time interval from ois 9c ussel interstadial to ois 5e ribains eemian interglacial in the organic sediments from the amargiers interstadial ois 9a a trachytic layer ar ar dated to ca 275 ka enables a correlation to be established with the upper part of a sequence derived from the nearby praclaux crater the lower part of this sequence being of holsteinian age ois 11c the cross dating of the pollen sequences from lac du bouchet cores h i and d and from praclaux provides a complete record from the massif central southern france of successive glacial and interglacial episodes that span the last ca 400 ka that is the interval from the holsteinian to the holocene

a contribution towards the palynostratigraphical classification of the middle pleistocene in central europe the pollen record of the neualbenreuth maar northeastern bavaria germany abstract palaeoecological evidence of intra saalian warm stages in central europe which was strongly affected by glacial and periglacial processes during the major middle and late pleistocene cold periods is ambiguous so far recently the first continuous sedimentary sequence of central europe containing the saalian complex mis 8 6 with the eemian interglacial in stratigraphic superposition was recovered from the newly discovered neualbenreuth maar ne bavaria here we present palynological results from this record allowing us to critically discuss the available biostratigraphical evidence of alternating intra saalian warm cold intervals from central europe the new pollen record from the neualbenreuth maar comprises a continuous record of vegetation and climate changes encompassing four warm stages and five cold periods the dominance of cold and dry tolerant herbs and the sparse representation of pioneer trees and shrubs during most parts of the sequence indicate open landscapes of steppe to woody steppe character typical of late middle and late pleistocene glacial periods in central europe the pollen assemblages of the warm stage in the upper part of the core clearly support its correlation with the eemian interglacial the three pre eemian warm stages represent terrestrial analogues of the marine isotope stages mis 7e 7c and 7a during each of these intervals forests were established but the reduced abundances and lower diversity of thermophilous and sub oceanic elements in comparison to the eemian attest to a weak interglacial character each of these interglacials shows a similar vegetation succession and only minor differences in the vegetation composition the intervening stadial periods represent a strong mis 7d and a moderate mis 7b climate deterioration respectively the vegetation and climate succession during the saalian glacial interglacial complex of neualbenreuth is broadly in line with the respective palynological signature from the velay record french massif central and the hoogeveen interstadial the netherlands in contrast there is only limited correspondence with most pollen records from northern and southern central europe which were hitherto classified as mis 7

vegetation and climate during warmer intervals in the late pleistocene of western and central europe abstract many warmer intervals occurred during the last interglacial glacial cycle 130 10 ka in europe the vegetational record shows several types of such intervals among which the forest periods of the eemian interglacial and the amersfoort brorup interstadials of the early weichselian are of special interest a series of map reconstructions is used to present some of the relevant vegetational and paleoclimatic characterizations they represent two types of temperate intervals occurring in the late pleistocene in europe one with a rather uniform distribution of vegetation types a warmer oceanic climate and a high sea level the other type shows strong vegetation gradients both north south and east west a more continental climate and a relatively low sea level inland ice probably persisted in the far north during this last type of interval it is suggested that these two types of interglacial occurred throughout the pleistocene

saalian supercycle mindel riss interglacial and milankovitch s dating abstract there are five pleistocene glacial interglacial cycles recorded in deep sea sediments from the last half million years but only two classic interglacials are recognized on land the dilemma stems from the different understanding and identification of glacials and interglacials in the geologic records on land and in the ocean only those intervals of warm climate that followed a major southward ice sheet advance and were accompanied by a deep penetrating oceanic transgression were recognized in their type areas of northern europe as true interglacials only those ice advances which left moraines farther south than younger ones were recognized as glacials in contrast all intervals reflecting exceptionally low global ice volume high sea level and warm sea surface are taken as interglacials in the deep sea record classic subdivisions are aligned with the glacial interglacial cycles of marine isotope stage stratigraphies by proposed higher order units called supercycles sc bracketed by superterminations st the saalian supercycle sc2 includes glacial cycles c d and e composed of marine isotope stages mis 6 7 8 9 10 and 11 the units mis 7 to mis 11 correspond to the great gross interglacial estimated from the early geologic considerations to be about 240 millennia long penck and bruckner 1909 die alpen im eiszeitalter vols 1 3 christian herman tauchnitz leipzig and determined from astronomic computations to last 235 millennia milankovitch 1941 kanon der erdbestrahlung und seine anwendung auf das eiszeitenproblem academie royale serbe editions speciales section des sciences mathematiques et naturelles tome cxxxiii stamparija mihaila curcica beograd 633pp the current high precision radiometric dating fully confirms the accuracy of milankovitch s determination and the pivotal role of orbital mechanisms in pleistocene climate change