1 - Baikal drilling project

Abstract

This chapter outlines the history of the Baikal drilling project and describes the main results of this project. The aim of this project is to study the paleoclimate in Central Asia through a comprehensive study of Lake Baikal sediment. A drilling rig that operates in an environmentally friendly manner is specially manufactured for this project. This rig is capable of drilling a sediment core of up to 1000 m at a depth of 900 m below the lake surface. The sedimentation pattern of the samples is dependent on the climate and topographical features of the area. Dense terrigenous clays formed during cold glacial periods, while sediments containing large amounts of diatom fossils were deposited during the interglacial periods. This alternating sediment pattern is typical of underwater uplifts that are isolated from the lakeshore by deep basins. A significant amount of sedimentation in the deep basins arises from turbidite flows, which also brings a large amount of fossilized vegetation. Gas hydrates, which were collected in fresh water also form in the deep basins. A continuous 5 Ma paleoclimatic record is obtained from the Academician Ridge, which correlates well with the oceanic oxygen curve. The paleoclimate of Central Asia is reconstructed by using the distribution of diatoms and biogenic silica content. The Lake Baikal paleoclimatic record is continuous and well dated and can be regarded as an excellent source of information on the paleoclimatology of continental interiors. As a result of investigations on the continuous Baikal record and its accurate dating, the age of several global events influencing Central Asia, the Eurasian continent, and the northern hemisphere have been more precisely dated.