Holocene era

During the middle Holocene era, occasional summer rainy intervals (see ref. 22) carried desert sediments down the Great Wadi into the modern flood plain, building up a succession of alluvial fans under what would later be the site of the walled city of Nekhen (Kom el Ahmr). The level of Nile flooding in this area (marked by the Nekhen lithozone) reached to within about 100 m of the modern boundary between the cultivation and the low desert, at an elevation of approximately 80 m above sea level. 

The appearance of domesticated species (Neolithic Period, Iron Age) and the gradual extermination of the large mammals (aurochs, wisent, moose, bear) which survived the Pleistocene and adapted to the Holocene are characteristic of the late period of this era. Those data are supplemented, among others, by botanical and archaeological remains, which, when combined, will lead to a better understanding of the events of the last phase of palaeohistory. 

The Cenozoic Era (c.65 million years BP to the present) encompasses the Tertiary and the Quaternary Periods. During the Tertiary the Earth s climate began an overall cooling trend of about 12 °C in the past 40 million years. Over the past two and a half million years the climate has varied from cool to warm periods, accompanied by massive expansions and contractions of the polar ice caps. This period of climate fluctuation is termed the Quaternary Period and spans the geologic time scale from the end of the Pliocene Epoch, roughly 1.8-2.6 million years ago, to the present. The Quaternary Period includes the Pleistocene and Holocene Epochs, with the Holocene... 

Holocene (Recent) 1) Time The last epoch within the Quaternary Period and the Ceno-zoic Era, equivalent to Oxygen Isotope Stage 2. Traditionally defined to have begun at 10 ka, some now place the boundary at approximately 10.8 ka, at the end of the Younger Dryas event. 2) Rocks The rocks or sediment formed during the Holocene Epoch, also known as the Flandrian in Britain. 

Quaternary 1) Time The second and last period in the Cenozoic Era. Normally, it is subdivided into the Holocene (Recent) and Pleistocene Epochs. The short chronology places its beginning at the traditionally defined boundary atroughly 1.78 Ma, while the long chronology places it at the start of the Matuyama Magnetochron at approximately 2.48 Ma. 2) Rocks The sediment and rocks formed during the Quaternary Period. 

A number of reputable scientists now believe that the Holocene is ending and a new era is beginning. What is the Holocene What is the new era that may well be replacing it and how does it relate to the material in this chapter What are some of the environmental implications of this change ... 

Cenozoic era Quaternary Holocene Pleistocene 0-0.0115 0.0115-1.81 Homo Erectus breakout... 

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