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42-508: ICS stages / ages (official) Blytt–Sernander stages/ages *Relative to year 2000 ( b2k ). The Atlantic in palaeoclimatology was the warmest and moistest Blytt–Sernander period , pollen zone and chronozone of Holocene northern Europe . The climate was generally warmer than today. It was preceded by the Boreal , with a climate similar to today's, and was followed by the Subboreal ,

84-621: A narrow belt along the Himalayas to cover mainland and island Southeast Asia as far as Sumatra , Java , Borneo , and Palawan . Finally, oaks of multiple sections ( Cyclobalanopsis , Ilex , Cerris , Quercus and related genera like Lithocarpus and Castanopsis ) extend across east Asia including China, Korea, and Japan. Potential records of Quercus have been reported from Late Cretaceous deposits in North America and East Asia. These are not considered definitive, as macrofossils older than

126-485: A range of flavours, colours, and aromas. The spongy bark of the cork oak is used to make traditional wine bottle corks. Almost a third of oak species are threatened with extinction due to climate change, invasive pests , and habitat loss . In culture, the oak tree is a symbol of strength and serves as the national tree of many countries. In Indo-European and related religions, the oak is associated with thunder gods . Individual oak trees of cultural significance include

168-460: A relatively short period. Thermophilous ("heat-loving") species migrated northward. They did not replace the species that were there, but shifted the percentages in their favor. Across middle Europe, the boreal forests were replaced by climax or "old growth" deciduous ones, which, though providing a denser canopy, were more open at the base. The dense canopy theory, however, has been questioned by F. Vera . Oak and hazel require more light than

210-508: A single oak tree produces both staminate ('male') flowers in the form of catkins , and small pistillate ('female') flowers, meaning that the trees are monoecious . The fruit is a nut called an acorn , borne in a cup-like structure known as a cupule ; each acorn usually contains one seed and takes 6–18 months to mature, depending on the species. The acorns and leaves contain tannic acid , which helps to guard against fungi and insects. There are some 500 extant species of oaks. Trees in

252-546: A small area of the west of Cuba ; in Mesoamerica it occurs mainly above 1000 metres. The genus crossed the isthmus of Panama when the northern and southern continents came together and is present as one species, Q. humboldtii , above 1000 metres in Colombia. The oaks of North America are of many sections ( Protobalanus , Lobatae , Ponticae , Quercus , and Virentes ) along with related genera such as Notholithocarpus . In

294-572: A transition to the modern. Because it was the warmest period of the Holocene, the Atlantic is often referenced more directly as the Holocene climatic optimum , or just climatic optimum. The Atlantic is equivalent to pollen zone VII . Sometimes a Pre-atlantic or early Atlantic is distinguished, on the basis of an early dividing cold snap. Other scientists place the Atlantic entirely after the cold snap, assigning

336-519: Is a hardwood tree or shrub in the genus Quercus of the beech family . They have spirally arranged leaves, often with lobed edges, and a nut called an acorn , borne within a cup. The genus is widely distributed in the Northern Hemisphere; it includes some 500 species, both deciduous and evergreen . Fossil oaks date back to the Middle Eocene . Molecular phylogeny shows that the genus

378-439: Is allowed by the dense canopy. Vera hypothesizes that the lowlands were more open and that the low frequency of grass pollen was caused by the browsing of large herbivores, such as aurochs and wild horses , a thesis referred to as the wood-pasture hypothesis . During the Atlantic period the deciduous temperate zone forests of south and central Europe extended northward to replace the boreal mixed forest, which found refugia on

420-471: Is divided into Old World and New World clades , but many oak species hybridise freely, making the genus's history difficult to resolve. Ecologically, oaks are keystone species in habitats from Mediterranean semi-desert to subtropical rainforest . They live in association with many kinds of fungi including truffles . Oaks support more than 950 species of caterpillar , many kinds of gall wasp which form distinctive galls , roundish woody lumps such as

462-576: Is essentially a permanent working subcommittee , which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or membership of the whole . One of its main aims, a project begun in 1974, is to establish a multidisciplinary standard and global geologic time scale that will ease paleontological and geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype Section and Points (GSSPs) within

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504-452: Is from Old English ac (seen in placenames such as Acton , from ac + tun , "oak village" ), which in turn is from Proto-Germanic *aiks , "oak". Oaks are hardwood ( dicotyledonous ) trees, deciduous or evergreen, with spirally arranged leaves , often with lobate margins ; some have serrated leaves or entire leaves with smooth margins. Many deciduous species are marcescent , not dropping dead leaves until spring. In spring,

546-628: The International Stratigraphic Chart , a combined working proposal and guideline-to-date released after the last ICS deliberations prior to the upcoming (next) meeting of the IUGS. Until the IUGS accepts the recommendations, they are unofficial since the IUGS parent approves or dismisses the individual deliberation reports of the ICS, which are presented as recommendations, and span dating and strata selection criteria, and related issues including nomenclatures. In de facto everyday matters,

588-774: The Neogene System and Neogene Period. Despite the strong debate, the Quaternary saw official ratification as a geological unit from the IUGS in June 2009, placing its lower boundary to the Gelasian Stage/Age at Monte San Nicola, Sicily, Italy (until then uppermost part of the Pliocene Series/Epoch, and thus of the Neogene System/Period), 2.58 Ma BP . In addition to publishing paper and document (PDF) versions of

630-622: The Paleogene , and possibly from before the Eocene are mostly poorly preserved without critical features for certain identification. Amongst the oldest unequivocal records of Quercus are pollen from Austria, dating to the Paleocene -Eocene boundary, around 55 million years ago. The oldest records of Quercus in North America are from Oregon , dating to the Middle Eocene, around 44 million years ago, with

672-523: The Rhine , extending northward in tributary drainage systems, a new factor entered the forest country: the Linear Pottery culture , clearing the arable land by slash and burn methods. It flourished about 5500–4500 BC, falling entirely within the Atlantic. By the end of the Atlantic, agricultural and pasture lands extended over much of Europe and the once virgin forests were contained within refugia . The end of

714-810: The Royal Oak in Britain, the Charter Oak in the United States, and the Guernica Oak in the Basque Country . The generic name Quercus is Latin for "oak", derived from Proto-Indo-European *kwerkwu- , "oak", which is also the origin of the name " fir ", another important or sacred tree in Indo-European culture. The word "cork", for the bark of the cork oak , similarly derives from Quercus . The common name "oak"

756-436: The oak apple , and a large number of pests and diseases. Oak leaves and acorns contain enough tannin to be toxic to cattle, but pigs are able to digest them safely. Oak timber is strong and hard, and has found many uses in construction and furniture-making. The bark was traditionally used for tanning leather . Wine barrels are made of oak; these are used for aging alcoholic beverages such as sherry and whisky , giving them

798-556: The paleontology , geology , geobiology and chronostratigraphy fields, among others. The International Commission on Stratigraphy has spawned numerous subcommittee level organizations organized and mobilized on a local country-wide or regional basis that are the true working committees of the IUGS, and these do the field work, basis comparisons in conference or co-ordination research committee meetings of local or wide-scale scope. The ICS publishes various reports and findings as well as revised references periodically, summarized in

840-530: The Atlantic is signaled by the "Elm decline", a sharp drop in Elm pollen, thought to be the result of climate, disease or human food-producing activities. In the subsequent cooler Sub-Boreal, forested country gave way to open range once more. The best picture of Atlantic Period fauna comes from the kitchen middens of the Ertebølle culture of Denmark and others like it. Denmark was more of an archipelago . Humans lived on

882-565: The Early Atlantic forest was but slightly affected by the rise in temperature. The forest had been pine with an underbrush of hazel, alder, birch, and willow . Only about 7% of the forest became broad-leaved deciduous, dropping to Boreal levels in the cooling of the Middle Atlantic. In the warmer Late Atlantic, the broad-leaved trees became 34% of the forest. Along the line of the Danube and

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924-714: The International Stratigraphic Chart, the ICS also provides a machine-readable version of the chart formulated using the Web Ontology Language (OWL) and, in particular, Time Ontology in OWL . The ICS' chart web page also provides an interactive version of the chart, based on the OWL data. The logo of International Commission on Stratigraphy was designed after the Chinese character of "mountain", 山. Quercus See also List of Quercus species . An oak

966-687: The Old World, oaks of section Quercus extend across the whole of Europe including European Russia apart from the far north, and north Africa (north of the Sahara) from Morocco to Libya. In Mediterranean Europe, they are joined by oaks of the sections Cerris and Ilex , which extend across Turkey, the Middle East, Iran, Afghanistan and Pakistan , while section Ponticae is endemic to the western Caucasus in Turkey and Georgia . Oaks of section Cyclobalanopsis extend in

1008-562: The coastline and lake margins of Denmark. Late in the Atlantic, Kongemose culture settlements were abandoned because of the rising water of the Littorina Sea ; and the succeeding Ertebølle culture (5400–3900 BC) settled more densely on the new shorelines. Northeastern Europe was uninhabited in the Early Atlantic. When the Mesolithic Sertuan Culture appeared there in the Middle Atlantic, around 7000 BP, it already had pottery and

1050-495: The deliberative results reported out of any meetings of the ICS are widely accepted and immediately enter everyday use, except in the rare cases where they result in a strong body of dissenting opinion, which matters are resolved before the full IUGS. One such controversy arose in 2009 when the ICS deliberated and decided that the Pliocene Series of the current but unofficially named Quaternary Period should be shifted into

1092-665: The former plains mammals had abandoned the country. They remained in the open forest and meadows. These include the aurochs , ancestor of cattle, and the wild horse which, as a discovery, was something of a revelation. The horses were not entirely hunted out, were not confined to the plains further east, and were not entirely the property of the Indo-European cultures there. The Mesolithic Ertebølle people were hunting them in Denmark. Human cultures of Northern Europe were primarily Mesolithic . The Kongemose culture (6400–5400 BC) settled on

1134-598: The fossil record. (i.e. section of the rock record as of a core sample section or accessible exposed strata, which when a core sample are usually "trayed" in long pieces, also called "sections" about a meter in length.) Additionally the ICS defines an alternative type of benchmark and criteria called Global Standard Stratigraphic Ages (GSSAs) where the characteristics and dating criteria set solely by physical sciences methods (such as magnetic alignment sequences, radiological criteria, etcetera.) as well as encouraging an international and open debate amongst Earth scientists in

1176-404: The genus Quercus consisted of Old World and New World clades. The entire genome of Quercus robur (the pedunculate oak) has been sequenced , revealing an array of mutations that may underlie the evolution of longevity and disease resistance in oaks. In addition, hundreds of oak species have been compared (at RAD-seq loci), allowing a detailed phylogeny to be constructed. However,

1218-625: The genus are often large and slow-growing; Q. alba can reach an age of 600 years, a diameter of 13 feet (4.0 m) and a height of 145 feet (44 m). The Granit oak in Bulgaria, a Q. robur specimen, has an estimated age of 1637 years, making it the oldest oak in Europe. The Wi'aaSal tree, a live oak in the reservation of the Pechanga Band of Indians , California, is at least 1000 years old, and might be as much as 2000 years old, which would make it

1260-510: The largest number of oak species, with approximately 160 species in Mexico, of which 109 are endemic, and about 90 in the United States. The second greatest area of oak diversity is China, with approximately 100 species. In the Americas, Quercus is widespread from Vancouver and Nova Scotia in the south of Canada, south to Mexico and across the whole of the eastern United States. It is present in

1302-462: The latter to the Boreal. The period is still in the process of definition. It is a question of definition and the criteria: Beginning with the temperatures, as derivable from Greenland ice core data, it is possible to define an 'Early' or 'Pre-Atlantic' period at around 8040 BC, where the O isotope line remains above 33 ppm in the combined curve after Rasmussen et al. (2006), which then would end at

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1344-413: The lofty canopy could be found a continuous zone of smaller animals, such as the ubiquitous squirrel ( Sciuris vulgaris ). Daubenton's bat ( Myotis daubentonii ) was common. In and around the big trees hunted the wildcat , pine marten , polecat ( Mustela putorius ), and wolf . The forest floor was prolific with larger browsers and rooters such as the red deer , roe deer , and wild boar . Not all

1386-512: The mountain slopes. Mistletoe , Water Chestnut ( Trapa natans ) and Ivy ( Hedera helix ) were present in Denmark . Grass pollen decreased. Softwood forests were replaced by hardwood. Birch and pine were replaced by oak , linden (lime, both small and large leaf species), beech , oak , hazel , elm , alder , and ash , spreading to the north from further south. The period is sometimes called "the alder-elm-lime period". In northeast Europe,

1428-547: The oldest oak in the US. Among the smallest oaks is Q. acuta , the Japanese evergreen oak. It forms a bush or small tree to a height of some 30 feet (9.1 m). The genus Quercus is native to the Northern Hemisphere and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas , Asia, Europe, and North Africa. North America has

1470-855: The oldest records in Asia from the Middle Eocene of Japan; both forms have affinities to the Cyclobalanopsis group. Quercus forms part, or rather two parts, of the Quercoideae subfamily of the Fagaceae , the beech family. Modern molecular phylogenetics suggests the following relationships: Fagus (beeches) Trigonobalanus (3 evergreen species) Lithocarpus (stone oaks) Chrysolepis (chinquapins) Quercus pro parte Notholithocarpus (tan oak) Quercus pro parte Castanopsis (also called chinquapins) Castanea (chestnuts) Molecular techniques for phylogenetic analysis show that

1512-399: The ringed, harp and grey. Mesolithic man hunted them and whales in the estuaries. The main birds were maritime: the red-throated diver , the black-throated diver , and the gannet . The Dalmatian pelican ( Pelecanus crispus ), which is now found only as far north as south-eastern Europe, has been found in Denmark. The capercaillie , as is the case now, was found in forested areas. In

1554-461: The rise. Each period has its distinctive ratios of species. According to the ice-core criterion it is extremely difficult to find a clear boundary, because the measurements still differ too much and alignments are still under construction. Many find a decline of temperature significant enough after 4800 BC. Another criterion comes from bio-stratigraphy: the elm -decline. However, this appears in different regions between 4300 and 3100 BC. The Atlantic

1596-563: The shorelines, exploiting waters rich in marine life, marshes teeming with birds, and forests where deer and boars as well as numerous small species were plentiful. The higher water levels offset the effects of the submarine toxic zone in the Baltic Sea . It contained fish now rare there, such as the anchovy , Engraulis encrasicolus, and the three-spined stickleback , Gasterosteus aculeatus . Also available were pike , whitefish , cod , and ling . Three kinds of seals were found there,

1638-553: The south, the Linear Pottery culture had already spread into the riverlands of Central Europe and was working a great transformation of the land. On the steppe to the east, the Samara culture was deeply involved with large numbers of horses, but it is not yet clear in what capacity. International Commission on Stratigraphy It is the largest subordinate body of the International Union of Geological Sciences (IUGS). The ICS

1680-522: The well-known 6.2 ka BC (8.2 ka calBP)-cold-event . Or one single Atlantic period is defined, starting at that just mentioned cold-event. After a lake-level criterion, Kul’kova and others define the Atlantic as running from 8000 to 5000 (cal?) BP. Early Atlantic, or AT1, was a time of high lake levels, 8000–7000 BP; in Middle Atlantic, AT2, lakes were at a lower level, 7000–6500 BP; and in Late Atlantic I, 6500–6000 BP, and II, 6000–5700 BP, levels were on

1722-420: Was a time of rising temperature and marine transgression on the islands of Denmark and elsewhere. The sea rose to 3 m above its present level by the end of the period. The oysters found there required lower salinity. Tides of up to 1 m were present. Inland, lake levels in all north Europe were generally higher, with fluctuations. The temperature rise had the effect of extending southern climates northward in

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1764-502: Was more sedentary than earlier hunter-gatherers, depending on the great abundance of wildlife. Pottery was being used around the lower Don and Volga from about 8000 BP. In the Late Atlantic, Sertuan culture evolved into Rudnya culture, which used pottery like that of the Narva and Dnieper-Donets cultures. That use of pottery upsets the idea that pottery belongs to the Neolithic. Further to

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