Glacial History of the Holocene
A global chronology of the Holocene was proposed by Porter and Denton, based on the glacial fluctuations then known for the North American cordillera. The fluctuations of Alpine glaciers in the Holocene occurred in response to quite small fluctuations in temperature. In the late 1990s, additional botanical material was used to trace Holocene climate history in Switzerland and a chronology was developed which appears to correspond quite well with the one derived from glacier advances and retreats. At the beginning of the Holocene, when the inland ice sheet was disintegrating rapidly, most of Scandinavia still lay under ice, its greatest thickness being in the northern Gulf of Bothnia. The moraines contain comminuted pumice lapilli, possibly because the Holocene glaciers ploughed over and incorporated parts of Glacier Peak tephra layers. Warming during the early Holocene was presumably accompanied by increased precipitation.