Oldest Dryas
Encyclopedia
Stadial
A stadial is a period of lower temperatures during an interglacial separating the glacial periods of an ice age. Such periods are of insufficient duration or intensity to be considered glacial periods...
after the Weichselian glaciation in north Europe. In the Alps
Alps
The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
, the Oldest Dryas corresponds to the Gschnitz
Gschnitz
Gschnitz is a municipality with 415 inhabitants in the southern part of the District Innsbruck-Land and is located 25 km south of Innsbruck at an elevation of 1242 m.-Setting:...
stadial of the Würm glaciation. The three “Dryas” periods (younger, older, oldest) are named for a marker species, Dryas octopetala
Dryas octopetala
Dryas octopetala is an arctic-alpine flowering plant in the family Rosaceae. It is a small prostrate evergreen subshrub forming large colonies, and is a popular flower in rock gardens...
, detected in core sample
Core sample
A core sample is a cylindrical section of a naturally occurring substance. Most core samples are obtained by drilling with special drills into the substance, for example sediment or rock, with a hollow steel tube called a core drill. The hole made for the core sample is called the "core hole". A...
s of glacial ice and peat bogs. The Oldest Dryas corresponds to pollen zone
Pollen zone
Pollen zones are a system of subdividing the last glacial period and Holocene paleoclimate using the data from pollen cores. The sequence provides a global chronological structure to a wide variety of scientists, such as geologists, climatologisists, geographists and archaeologists, who study the...
Ia.
Dating
Before Present
Before Present years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use AD 1950 as the origin of the age scale, reflecting the fact that radiocarbon...
, from Roberts, 1998. A date from Kilkeel
Kilkeel
Kilkeel is a small town in County Down, Northern Ireland. It is the main fishing port on the Down coast, and its harbour houses one of the largest fishing fleets in Ireland. It had a population of 6,338 people according to the 2001 Census...
, Northern Ireland
Northern Ireland
Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...
, extends the start of the period to as early as 19,000 BP. A strong sequence of C-14 dates derived from layered material in the Hauterive/Rouges-Terres excavations on the northwest shore of Lake Neuchâtel
Lake Neuchâtel
Lake Neuchâtel is a lake in Romandy, Switzerland . The lake lies mainly in the canton of Neuchâtel, but is also shared by the cantons of Vaud, of Fribourg, and of Bern....
in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
, 1992–1993, places the end of the Oldest Dryas at about 14,650 BP calibrated. The same date from Antarctica and the south China sea is 14,600 and 14,700, respectively, while a Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
ice core indicates 14,500.
The ultimate standard to which all these dates are to be compared is the graph of the oxygen isotope ratio cycle
Oxygen isotope ratio cycle
Oxygen isotope ratio cycles are cyclical variations in the ratio of the abundance of oxygen with an atomic mass of 18 to the abundance of oxygen with an atomic mass of 16 present in some substances, such as polar ice or calcite in ocean core samples. The ratio is linked to water temperature of...
s, which gives change in isotope concentration on the y-axis versus time on the x-axis. The graph plots many events that are sharply defined, but others are not. The selection of a terminal point is sometimes partially arbitrary.
The end of the Oldest Dryas is sharply defined. The beginning is a long, gently sloping band, probably no earlier than 19,000 BP, but the date might be set later by approximately 1000 years. Data derived from isotope variation of nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
and argon
Argon
Argon is a chemical element represented by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table . Argon is the third most common gas in the Earth's atmosphere, at 0.93%, making it more common than carbon dioxide...
trapped in Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
ice gives a high-resolution date for the end of the oldest Dryas at the sharp temperature rise of 14.67 ky BP.
Late Pleistocene climate sequence
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Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
climatic periods defined for northern Europe are the Oldest Dryas, the Bölling
Bølling Oscillation
The Bølling oscillation was a warm interstadial period between the Oldest Dryas and Older Dryas stadials, at the end of the last glacial period. It is named after a peat sequence discovered at Bølling lake, central Jutland...
(interstadial), the Older Dryas
Older Dryas
The Older Dryas was a stadial period between the Bølling and Allerød oscillations during the Pleistocene glacial period of ~11,700—12,000 uncalibrated years ago...
(stadial), the Allerød
Allerød Oscillation
The Allerød period was a warm and moist global interstadial that occurred at the end of the last glacial period. The Allerød oscillation raised temperatures , before they declined again in the succeeding Younger Dryas period, which was followed by the present interglacial period.In some regions,...
(interstadial), and the Younger Dryas
Younger Dryas
The Younger Dryas stadial, also referred to as the Big Freeze, was a geologically brief period of cold climatic conditions and drought between approximately 12.8 and 11.5 ka BP, or 12,800 and 11,500 years before present...
(stadial). The Holocene
Holocene
The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...
begins immediately afterward. The last three just mentioned are also Blytt-Sernander
Blytt-Sernander
The Blytt-Sernander classification, or sequence, is a series of north European climatic periods or phases based on the study of Danish peat bogs by Axel Blytt and Rutger Sernander...
periods.
Sometimes the Older Dryas is missing, as in the Jura
Jura mountains
The Jura Mountains are a small mountain range located north of the Alps, separating the Rhine and Rhone rivers and forming part of the watershed of each...
of France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, or is negligible in the evidence. In that case, the initial part of the sequence appears to be: Oldest Dryas (cold), Bølling-Allerød (warm), Younger Dryas (cold). The Bølling-Allerød corresponds to the Windermere
Windermere
Windermere is the largest natural lake of England. It is also a name used in a number of places, including:-Australia:* Lake Windermere , a reservoir, Australian Capital Territory * Lake Windermere...
interstadial in Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
.
Often, however, the apparently missing Older Dryas is a problem of resolution in the evidence. Some scientists have undertaken “high-resolution” studies, which combine a variety of climatological methods. These studies, such as the ones conducted on Owens
Owens Lake
Owens Lake is a mostly dry lake in the Owens Valley on the eastern side of the Sierra Nevada in Inyo County, California. It is located about south of Lone Pine, California...
and Mono
Mono Lake
Mono Lake is a large, shallow saline lake in Mono County, California, formed at least 760,000 years ago as a terminal lake in a basin that has no outlet to the ocean...
lakes in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, usually detect the Older Dryas. Even when detected, the Older Dryas appears to be no more than a few centuries of slightly cooler weather on the oxygen isotope ratio graph.
Flora
During the Oldest Dryas, a treeless Europe similar to the Arctic tundraTundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
presented itself. It contained shrubs and herbaceous plants such as:
- PoaceaePoaceaeThe Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...
, grasses - ArtemisiaArtemisia (plant)Artemisia is a large, diverse genus of plants with between 200 to 400 species belonging to the daisy family Asteraceae. It comprises hardy herbs and shrubs known for their volatile oils. They grow in temperate climates of the Northern Hemisphere and Southern Hemisphere, usually in dry or semi-dry...
- Betula nanaDwarf BirchBetula nana is a species of birch in the family Betulaceae, found mainly in the tundra of the Arctic region.-Description:...
, dwarf birch - Salix retusaDwarf WillowSalix herbacea is a species of tiny creeping willow adapted to survive in harsh Arctic and sub-Arctic environments...
, dwarf willow - Dryas octopetalaDryas octopetalaDryas octopetala is an arctic-alpine flowering plant in the family Rosaceae. It is a small prostrate evergreen subshrub forming large colonies, and is a popular flower in rock gardens...
Fauna
Species are mainly Arctic; however, during the glacial maximum the warmer weather species had withdrawn into refugia. Starting in the oldest Dryas they began to repopulate Europe.The brown bear, Ursos arctos
Brown Bear
The brown bear is a large bear distributed across much of northern Eurasia and North America. It can weigh from and its largest subspecies, the Kodiak Bear, rivals the polar bear as the largest member of the bear family and as the largest land-based predator.There are several recognized...
, was among the first to arrive in the north. Genetic studies indicate north European brown bears came from a refugium in the Carpathians
Carpathian Mountains
The Carpathian Mountains or Carpathians are a range of mountains forming an arc roughly long across Central and Eastern Europe, making them the second-longest mountain range in Europe...
of Moldavia
Moldavia
Moldavia is a geographic and historical region and former principality in Eastern Europe, corresponding to the territory between the Eastern Carpathians and the Dniester river...
. Other refugia were in Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
, Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
and Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
.
The bears would not have returned north except in pursuit of food. The tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
must already have been well populated. It is likely that the species hunted by man at Lake Neuchâtel
Lake Neuchâtel
Lake Neuchâtel is a lake in Romandy, Switzerland . The lake lies mainly in the canton of Neuchâtel, but is also shared by the cantons of Vaud, of Fribourg, and of Bern....
in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
by the end of the period were present during it:
Aves
- Gavia arcticaBlack-throated DiverThe Black-throated Loon is a migratory aquatic bird found in the northern hemisphere. The species is known as an Arctic Loon in North America and the Black-throated Diver in Eurasia, its current name is a compromise proposed by the International Ornithological Committee.-Taxonomy:The...
, black-throated diver - Podiceps nigricollisBlack-necked GrebeThe Black-necked Grebe, Podiceps nigricollis, known in North America as the Eared Grebe, is a member of the grebe family of water birds. It occurs on every continent except Australia and Antarctica.-Taxonomy:There are three subspecies:*P. n...
, black-necked grebe - Cygnus cygnusWhooper SwanThe Whooper Swan , Cygnus cygnus, is a large Northern Hemisphere swan. It is the Eurasian counterpart of the North American Trumpeter Swan. An old name for the Whooper Swan is Elk; it is so called in Francis Willughby and John Ray's Ornithology of 1676.-Description:The Whooper Swan is similar in...
, whooper swan - Aquila chrysaetosGolden EagleThe Golden Eagle is one of the best known birds of prey in the Northern Hemisphere. Like all eagles, it belongs to the family Accipitridae. Once widespread across the Holarctic, it has disappeared from many of the more heavily populated areas...
, golden eagle
The above birds are primarily maritime. They must have fed in the copious glacial waters of the north just beginning to be released.
Fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
- Lota lotaBurbotThe burbot is the only gadiform fish inhabiting freshwaters. It is also known as mariah, the lawyer, and eelpout. It is closely related to the marine common ling and the cusk...
, burbot - Thymallus thymallusGrayling (species)The grayling is a species of freshwater fish in the salmon family of order Salmoniformes. It is the type species of its genus. Native to the Palearctic ecozone, the grayling is widespread throughout northern Europe, from the United Kingdom and France to the Ural Mountains in Russia...
, grayling - Rutilus rutilus, roach
- Salmo truttaTroutTrout is the name for a number of species of freshwater and saltwater fish belonging to the Salmoninae subfamily of the family Salmonidae. Salmon belong to the same family as trout. Most salmon species spend almost all their lives in salt water...
, trout - SalvelinusSalvelinusSalvelinus is a genus of salmonid fish often called char or charr; some species are called "trout". Salvelinus is a member of the Salmoninae subfamily of the Salmonidae family. Charr may be identified by light cream pink or red spots over a darker body. Scales tend to be small, with 115-200 along...
alpinus, char
The smaller mammals of the food chain inhabited the herbaceous blanket of the tundra:
Cricetidae
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...
- Discrotonyx torquatusLemmingLemmings are small rodents, usually found in or near the Arctic, in tundra biomes. They are subniveal animals, and together with voles and muskrats, they make up the subfamily Arvicolinae , which forms part of the largest mammal radiation by far, the superfamily Muroidea, which also includes rats,...
, collared lemming - Microtus oeconomusVoleA vole is a small rodent resembling a mouse but with a stouter body, a shorter hairy tail, a slightly rounder head, smaller ears and eyes, and differently formed molars . There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice in North America...
, root vole - Microtus arvalisVoleA vole is a small rodent resembling a mouse but with a stouter body, a shorter hairy tail, a slightly rounder head, smaller ears and eyes, and differently formed molars . There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice in North America...
, common vole - Chionmys nivalisVoleA vole is a small rodent resembling a mouse but with a stouter body, a shorter hairy tail, a slightly rounder head, smaller ears and eyes, and differently formed molars . There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice in North America...
, snowy vole
Leporidae
Leporidae
Leporids are the approximately 50 species of rabbits and hares which form the family Leporidae. The leporids, together with the pikas, constitute the mammalian order Lagomorpha. Leporids differ from pikas in having short furry tails, and elongated ears and hind legs...
- Lepus timidusMountain HareThe Mountain Hare , also known as Blue Hare, Tundra Hare, Variable Hare, White Hare, Alpine Hare and Irish Hare, is a hare, which is largely adapted to polar and mountainous habitats. It is distributed from Fennoscandia to eastern Siberia; in addition there are isolated populations in the Alps,...
, Arctic hare
Sciuridae
- Marmota marmotaMarmotThe marmots are a genus, Marmota, of squirrels. There are 14 species in this genus.Marmots are generally large ground squirrels. Those most often referred to as marmots tend to live in mountainous areas such as the Alps, northern Apennines, Eurasian steppes, Carpathians, Tatras, and Pyrenees in...
, marmot
In addition to the bears and the birds were other predators of these small animals:
Carnivora
Carnivora
The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...
- Felis lynxLynxA lynx is any of the four Lynx genus species of medium-sized wildcats. The name "lynx" originated in Middle English via Latin from Greek word "λύγξ", derived from the Indo-European root "*leuk-", meaning "light, brightness", in reference to the luminescence of its reflective eyes...
, lynx - Alopex lagopusArctic foxThe arctic fox , also known as the white fox, polar fox or snow fox, is a small fox native to Arctic regions of the Northern Hemisphere and is common throughout the Arctic tundra biome. The Greek word alopex, means a fox and Vulpes is the Latin version...
, Arctic fox - Canis lupus, wolf
Man was interested in the large mammals, which included:
- Rangifer tarandusReindeerThe reindeer , also known as the caribou in North America, is a deer from the Arctic and Subarctic, including both resident and migratory populations. While overall widespread and numerous, some of its subspecies are rare and one has already gone extinct.Reindeer vary considerably in color and size...
, reindeer - Equus ferusHorseThe horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...
, wild horse - Capra ibex, ibex
At some point the larger mammals arrived: the hyena
Hyena
Hyenas or Hyaenas are the animals of the family Hyaenidae of suborder feliforms of the Carnivora. It is the fourth smallest biological family in the Carnivora , and one of the smallest in the mammalia...
, wooly rhinoceros, cave bear
Cave Bear
The cave bear was a species of bear that lived in Europe during the Pleistocene and became extinct at the beginning of the Last Glacial Maximum about 27,500 years ago....
and mammoth
Mammoth
A mammoth is any species of the extinct genus Mammuthus. These proboscideans are members of Elephantidae, the family of elephants and mammoths, and close relatives of modern elephants. They were often equipped with long curved tusks and, in northern species, a covering of long hair...
.
Human prehistory
Cro-Magnon
The Cro-Magnon were the first early modern humans of the European Upper Paleolithic. The earliest known remains of Cro-Magnon-like humans are radiometrically dated to 35,000 years before present....
man, the first full humans. Neanderthal
Neanderthal
The Neanderthal is an extinct member of the Homo genus known from Pleistocene specimens found in Europe and parts of western and central Asia...
s had long since disappeared either by replacement or by amalgamation with modern man. The Magdalenian
Magdalenian
The Magdalenian , refers to one of the later cultures of the Upper Paleolithic in western Europe, dating from around 17,000 BP to 9,000 BP...
culture of reindeer hunters prevailed in west Europe. From the Carpathians
Carpathian Mountains
The Carpathian Mountains or Carpathians are a range of mountains forming an arc roughly long across Central and Eastern Europe, making them the second-longest mountain range in Europe...
eastward the Epigravettian continued the prior Gravettian
Gravettian
thumb|right|Burins to the Gravettian culture.The Gravettian toolmaking culture was a specific archaeological industry of the European Upper Palaeolithic era prevalent before the last glacial epoch. It is named after the type site of La Gravette in the Dordogne region of France where its...
. To the far east, the Jōmon culture had already become sedentary, was producing some food, and possibly grew rice, even though they were not at all urban. They were manufacturing the first pottery ever, as far as we know now.
One of the most remarkable discoveries of the period was the domestic wolf, a distinct breed of canis lupus with smaller teeth. The domestic dog, canis familiaris, also has been found. It is thought that these animals helped with the hunting, but they would by the nature of the hunt have gradually become adept at herding.