Topic –Introduction to Prehistory
Subtopic –Quaternary Period
Heading - Holocene (New 2019)
Holocene
Holocene environment and biota
In formerly glaciated regions, the Holocene has been a time for the reinstitution of
ordinary processes of subaerial erosion and progressive reoccupation by
a flora and fauna.
The latter expanded rapidly into what was an ecological vacuum, although with a
very restricted range of organisms, because the climates were initially cold and
the soil was still immature.
Floral change
The most important biological means of establishing Holocene climate
involves palynology, the study of pollen, spores, and other microscopic organic
particles.
Pollen from trees, shrubs, or grasses is generated annually in large quantities and
often is well preserved in fine-grained lake, swamp, or marine sediments.
Statistical correlations of modern and fossil assemblages provide a basis for
estimating the approximate makeup of the local or regional vegetation through time.
Even a crude subdivision into arboreal pollen (AP) and non-arboreal pollen (NAP)
reflects the former types of climate.
The tundra vegetation of the last glacial epoch, for example, provides predominantly
NAP, and the transition to forest vegetation shows the climatic amelioration that
heralded the beginning of the Holocene.
The first standard palynological stratigraphy was developed in Scandinavia by Axel
Blytt, Johan Rutger Sernander, and E.J. Lennart von Post, in combination with a
theory of Holocene climate changes.
The so-called Blytt–Sernander system was soon tied to the archaeology and to the
varve chronology of Gerard De Geer. It has been closely checked by radiocarbon
dating, establishing a very useful standard.
Every region has its own standard pollen stratigraphy, but these are
now correlated approximately with the Blytt–Sernander framework. To some extent
this is even true for remote areas such as Patagonia and East Africa.
Particularly important is the fact that the middle Holocene was appreciably warmer
than today. In Europe this phase has been called the Climatic Optimum (zones Boreal
to Atlantic), and in North America it has been called the hypsithermal (also
altithermal and xerothermic).
Like pollen, macrobotanical remains by themselves do not establish chronologies.
Absolute dating of these remains does, however, provide a chronology of floral
changes throughout the Holocene.
Subtopic –Quaternary Period
Heading - Holocene (New 2019)
Holocene
Holocene environment and biota
In formerly glaciated regions, the Holocene has been a time for the reinstitution of
ordinary processes of subaerial erosion and progressive reoccupation by
a flora and fauna.
The latter expanded rapidly into what was an ecological vacuum, although with a
very restricted range of organisms, because the climates were initially cold and
the soil was still immature.
Floral change
The most important biological means of establishing Holocene climate
involves palynology, the study of pollen, spores, and other microscopic organic
particles.
Pollen from trees, shrubs, or grasses is generated annually in large quantities and
often is well preserved in fine-grained lake, swamp, or marine sediments.
Statistical correlations of modern and fossil assemblages provide a basis for
estimating the approximate makeup of the local or regional vegetation through time.
Even a crude subdivision into arboreal pollen (AP) and non-arboreal pollen (NAP)
reflects the former types of climate.
The tundra vegetation of the last glacial epoch, for example, provides predominantly
NAP, and the transition to forest vegetation shows the climatic amelioration that
heralded the beginning of the Holocene.
The first standard palynological stratigraphy was developed in Scandinavia by Axel
Blytt, Johan Rutger Sernander, and E.J. Lennart von Post, in combination with a
theory of Holocene climate changes.
The so-called Blytt–Sernander system was soon tied to the archaeology and to the
varve chronology of Gerard De Geer. It has been closely checked by radiocarbon
dating, establishing a very useful standard.
Every region has its own standard pollen stratigraphy, but these are
now correlated approximately with the Blytt–Sernander framework. To some extent
this is even true for remote areas such as Patagonia and East Africa.
Particularly important is the fact that the middle Holocene was appreciably warmer
than today. In Europe this phase has been called the Climatic Optimum (zones Boreal
to Atlantic), and in North America it has been called the hypsithermal (also
altithermal and xerothermic).
Like pollen, macrobotanical remains by themselves do not establish chronologies.
Absolute dating of these remains does, however, provide a chronology of floral
changes throughout the Holocene.
