Palaeoclimatology and Palaeoceanography from Laminated Sediments
Palaeoclimatology and Palaeoceanography from Laminated Sediments

Author: Alan E. S. Kemp

Publisher: Geological Society of London

Published: 1996

Total Pages: 278

ISBN-13: 9781897799673

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The magnitude and causes of decadal to century-scale changes in climate are major issues of global concern. The separation of anthropogenically driven change from natural 'baseline' variability within the atmosphere/ocean system is a prerequisite to identifying human impact on global climate. An understanding of past climate variability is therefore a key to predicting future climate change. The sedimentary record of the oceans, seas and lakes is produced by a series of depositional events that occur on seasonal timescales but can rarely be resolved due to mixing of the sediment by bottomdwelling organisms. Where they are preserved, laminated sediments act like tree rings to record these seasonal-scale processes, such as plankton blooms and floods, and provide a uniquely high-resolution record of environmental change. In addition, annually laminated or 'varved' sediment sequences act as geochronometers against which other timescales can be tested. Laminated sediments may therefore be used to develop records of interannual and decadal-scale variability which serve to test models of climate change. The authors cover a range of topics that include strategies for study and techniques of analysis. A series of case studies, dealing with a variety of lacustrine and marine records, illustrates the wide potential of laminated sediments as palaeoclimatic and palaeoceanographic indicators.

Annual to Seasonal Resolution Analysis of Late Pleistocene and Holocene Sediment in Saanich Inlet, British Columbia, Canada
Annual to Seasonal Resolution Analysis of Late Pleistocene and Holocene Sediment in Saanich Inlet, British Columbia, Canada

Author: Kinuyo Kanamaru

Publisher:

Published: 2011

Total Pages: 263

ISBN-13:

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This thesis aims to combine long high-resolution sediment data with information on sedimentation processes in and around Saanich Inlet, to better understand the seasonal sedimentation mechanisms in Saanich Inlet from the late Pleistocene to the early Holocene. These understandings are used to establish sediment provenance in Saanich Inlet with seasonal to sub-seasonal resolution, and to help understand paleoclimatic variations between 10700 and 2150 14 C calibrated (cal) a BP (= cal yr BP). In Saanich Inlet, elemental variability within laminated sediments is largely controlled by mineralogical changes in the sediment caused by changes in sediment provenance and primary productivity. In particular, on Vancouver Island, gold and platinum group elements (PGE), occurring in soils as a result of weathering of metamorphic and igneous rocks during the process of pedogenesis, are only observed within a restricted area of naturally occurring minerals, which concentrate those elements in soil. Therefore, preferential deposition of such minor elements can be strongly related to a change in sediment provenance. Chalcophile elements, such as Cu, have successfully proven to be reliable indicators of heterogenic-origin and/or bottom water redox conditions. Furthermore, sediment provenance along the western slope basin near Bamberton are distinguished and identified by a strong expression of enriched excess CaCO3 in both organic (high Ca/Ti and Sr/Ca) and inorganic (high Ca/Ti and low Sr/Ca) forms. This dissertation is divided into five related and complementary parts. The first chapter introduces Saanich Inlet and provides an overview of climatic and oceanographic patterns. The second chapter explains the methodology used in this work, and the third and fourth chapters, which are intended for publication, examine paleoclimatic and oceanographic variability during selected intervals of the Holocene in sub-seasonal (third chapter) and multi-annual to decadal (fourth chapter) scales. The last chapter summarizes the conclusions. Because of this format, some repetition of the introductory material exists in the main chapters.

Fjord Systems and Archives
Fjord Systems and Archives

Author: John Allen Howe

Publisher: Geological Society of London

Published: 2010

Total Pages: 394

ISBN-13: 9781862393127

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"The current volume brings together a selection of papers which have variously, but not exclusively, been presented in recent years at one of three international meetings on the theme of Fjords. The first of these meetings on 'Fjord environments: past, present and future' was held as a workshop ...The second meeting was convened as a formal session (CGC-13) entitles 'Fjords: climate and environmental change' ..The third of these meetings, the 2nd International workshop on the theme Fjord environments: past, present and future ..." --p. [1].