Pollen zone
Encyclopedia
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"...
paleoclimate using the data from pollen core
Pollen core
A pollen core is a core sample of a medium containing a stratigraphic sequence of pollen. Analysis of the type and frequency of the pollen in each layer is used to study changes in climate or land use using regional vegetation as a proxy...
s. The sequence provides a global chronological structure to a wide variety of scientists, such as geologists
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
, climatologisist
Climatology
Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time, and is a branch of the atmospheric sciences...
s, geographists
Geography
Geography is the science that studies the lands, features, inhabitants, and phenomena of Earth. A literal translation would be "to describe or write about the Earth". The first person to use the word "geography" was Eratosthenes...
and archaeologists, who study the physical and cultural environment of the last 15,000 years.
History
The palynological aspects of the system were first investigated extensively by the SwedishSweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
palynologist
Palynology
Palynology is the science that studies contemporary and fossil palynomorphs, including pollen, spores, orbicules, dinoflagellate cysts, acritarchs, chitinozoans and scolecodonts, together with particulate organic matter and kerogen found in sedimentary rocks and sediments...
Lennart von Post
Lennart von Post
Ernst Jakob Lennart von Post was a Swedish naturalist and geologist. He was the first to publish quantitative analysis of pollen and is counted as one of the founders of palynology. He was a professor at Stockholm University 1929-1950.-Early life:Lennart von Post was born in Johannesberg, near...
in the years before the First World War
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. By analysing pollen 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 taken from peat
Peat
Peat is an accumulation of partially decayed vegetation matter or histosol. Peat forms in wetland bogs, moors, muskegs, pocosins, mires, and peat swamp forests. Peat is harvested as an important source of fuel in certain parts of the world...
bogs, von Post noticed that different plant species were represented in bands through the cores.
The differing species and differing quantities of the same species are caused by changes in climate. Von Post was able to confirm the 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...
climatic sequence showing fluctuations between warmer and colder periods across thousands of years. He used local peat sequences combined with varve
Varve
A varve is an annual layer of sediment or sedimentary rock.The word 'varve' is derived from the Swedish word varv whose meanings and connotations include 'revolution', 'in layers', and 'circle'. The term first appeared as Hvarfig lera on the first map produced by the Geological Survey of Sweden in...
dating to produce a regional climatic chronology for Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...
.
In 1940 Harry Godwin
Harry Godwin
Sir Harry Godwin FRS, was a prominent English botanist and ecologist of the 20th century. He had a long association with Clare College, Cambridge.-Early life:...
began applying von Post's methods to pollen cores from the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
to produce the wider European sequence accepted today. It basically expanded the Blytt-Sernander further into the late Pleistocene
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 ....
and refined some of its periods. Following the Second World War
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, the technique spread to the Americas.
Currently scientists are focusing a repertory of several different methods on 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 in peat, ice, lake and ocean bottoms, and sediments to achieve "high resolution" dating not possible to only one method: Carbon dating, Dendrochronology
Dendrochronology
Dendrochronology or tree-ring dating is the scientific method of dating based on the analysis of patterns of tree-rings. Dendrochronology can date the time at which tree rings were formed, in many types of wood, to the exact calendar year...
, isotope ratios
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...
on a number of gases, studies of insects and molluscs, and others. While often doubting the utility of the modified Bytt-Sernander, they seem to confirm and expand it all the more.
Sequence table
| Zone | Biostratigraphic division | Dates | Dominant plant type | Archaeological periods | Geological stage |
|---|---|---|---|---|---|
| IX | Sub-Atlantic | 500 BC to present | Spread of grasses and pine and beech woodland | Iron Age Iron Age The Iron Age is the archaeological period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing... onwards | Flandrian Flandrian interglacial The Flandrian interglacial or stage is the name given by geologists and archaeologists in the British Isles to the first, and so far only, stage of the Holocene epoch , covering the period from around 12,000 years ago, at the end of the last glacial period to the present day. As such, it is in... |
| VIII | Sub-Boreal | 3000 - 500 BC | Mixed oak forest | Bronze Age Bronze Age The Bronze Age is a period characterized by the use of copper and its alloy bronze as the chief hard materials in the manufacture of some implements and weapons. Chronologically, it stands between the Stone Age and Iron Age... and Iron Age Iron Age The Iron Age is the archaeological period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing... | Flandrian |
| VII | Atlantic Atlantic (period) 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 Sub-Boreal, a... | 5500 -3000 BC | Mixed oak forest | Neolithic Neolithic The Neolithic Age, Era, or Period, or New Stone Age, was a period in the development of human technology, beginning about 9500 BC in some parts of the Middle East, and later in other parts of the world. It is traditionally considered as the last part of the Stone Age... and Bronze Age | Flandrian |
| V and VI | Boreal Boreal (period) In paleoclimatology of the Holocene, the Boreal was the first of the Blytt-Sernander sequence of north European climatic phases that were originally based on the study of Danish peat bogs, named for Axel Blytt and Rutger Sernander, who first established the sequence. In peat bog sediments, the... | c. 7700 - 5500 BC | Pine/birch forest and increasing mixed forest | Mesolithic Mesolithic The Mesolithic is an archaeological concept used to refer to certain groups of archaeological cultures defined as falling between the Paleolithic and the Neolithic.... | Flandrian |
| IV | Pre-Boreal Boreal (period) In paleoclimatology of the Holocene, the Boreal was the first of the Blytt-Sernander sequence of north European climatic phases that were originally based on the study of Danish peat bogs, named for Axel Blytt and Rutger Sernander, who first established the sequence. In peat bog sediments, the... | c. 8300 - 7700 BC | Birch forest | Late Upper Palaeolithic and early - mid Mesolithic Mesolithic The Mesolithic is an archaeological concept used to refer to certain groups of archaeological cultures defined as falling between the Paleolithic and the Neolithic.... | Devensian glaciation and Flandrian |
| III | 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... | c. 8800 - 8300 BC | 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... | Late Upper Palaeolithic | Devensian |
| II | Allerød Oscillation 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,... | c. 9800 - 8800 BC | Tundra, Park Tundra Park Tundra Park tundra was a plant community that occurred in northwestern Europe after the last ice age ended. The community was similar to that found today at the boundary between tundra and taiga in Siberia: species included the dwarf birch and the least willow. Park tundra stretched as far south as the... and birch forest | Late Upper Palaeolithic | Devensian |
| Ic | 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... | c. 10,000 - 9800 BC | Tundra | Late Upper Palaeolithic | Devensian |
| Ib | Bølling Oscillation 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... | c. 10,500 - 10,000 BC | Park Tundra Park Tundra Park tundra was a plant community that occurred in northwestern Europe after the last ice age ended. The community was similar to that found today at the boundary between tundra and taiga in Siberia: species included the dwarf birch and the least willow. Park tundra stretched as far south as the... | Late Upper Palaeolithic | Devensian |
| Ia | Oldest Dryas Oldest Dryas The Oldest Dryas was a climatic period, which occurred during the coldest stadial after the Weichselian glaciation in north Europe. In the Alps, the Oldest Dryas corresponds to the Gschnitz stadial of the Würm glaciation. The three “Dryas” periods are named for a marker species, Dryas octopetala,... | c. 13,000 - 10,500 BC | Tundra | LateUpper Palaeolithic | Devensian |