Quaternary geology of the Inner Hebrides

1983 ◽  
Vol 83 ◽  
pp. 83-89
Author(s):  
J. D. Peacock
Keyword(s):  
Quaternary Geology ◽  
Geological History ◽  
Glacial Deposits ◽  
Marine Origin ◽  
The Past ◽  
Last Glaciation ◽  
History Of ◽  
Raised Beaches

SynopsisThe Quaternary features and deposits provide a record of the geological history of the past 18,000 years and only a few elements of the landscape, such as the glaciated rock platforms and cliffs of marine origin, can be ascribed to earlier times. Mainland ice almost certainly covered the islands during the last glaciation, its retreat being temporarily reversed or halted perhaps more than once. There was a final well-marked, but short-lived episode of valley glaciation some 10,000 to 11,000 years ago. Glacial deposits, raised beaches, periglacial features, landslips and the post-glacial accumulations of peat, shell sand and diatomite are discussed briefly.

scholarly journals Continuous vegetation record of the Greater Cape Floristic Region (South Africa) covering the past 300 thousand years (IODP U1479)

2021 ◽  
Author(s):  
Lydie M. Dupont ◽  
Xueqin Zhao ◽  
Chistopher Charles ◽  
J. Tyler Faith ◽  
David Braun
Keyword(s):  
South Africa ◽  
Vegetation History ◽  
Modern Human ◽  
Cape Floristic Region ◽  
Archaeological Record ◽  
The Past ◽  
Modern Human Origins ◽  
Last Glaciation ◽  
History Of ◽  
The Last Glacial

Abstract. The flora of the Greater Cape Floristic Region (GCFR) of South Africa is a biodiversity hotspot of global significance, and its archaeological record has contributed substantially to the understanding of modern human origins. For both reasons, the climate and vegetation history of south-western South Africa is of interest to numerous fields. Currently known paleo-environmental records cover the Holocene, the last glacial-interglacial transition and parts of the last glaciation but do not encompass a full glacial-interglacial cycle. To obtain a continuous vegetation record of the last Pleistocene glacial-interglacial cycles, we studied pollen, spores and micro-charcoal of deep-sea sediments from IODP Site U1479 retrieved from SW of Cape Town. We compare our palynological results of the Pleistocene with previously published results of Pliocene material from the same site. We find that the vegetation of the GCFR, in particular Fynbos and Afrotemperate forest, respond to precessional forcing of climate. The micro-charcoal record confirms the importance of fires in the Fynbos vegetation. Ericaceae-rich and Asteraceae-rich types of Fynbos could extend on the western part of the Palaeo-Agulhas Plain (PAP), which emerged during periods of low sea-level of the Pleistocene.

scholarly journals The Current State and 125 Kyr History of Permafrost in the Kara Sea Shelf: Modeling Constraints

2019 ◽  
Author(s):  
Anatoliy Gavrilov ◽  
Vladimir Pavlov ◽  
Alexandr Fridenberg ◽  
Mikhail Boldyrev ◽  
Vanda Khilimonyuk ◽  
...  
Keyword(s):  
Sea Level ◽  
Field Data ◽  
Ice Sheets ◽  
Forward Modeling ◽  
Kara Sea ◽  
Geological History ◽  
Freezing And Thawing ◽  
The Past ◽  
Current State ◽  
History Of

Abstract. The evolution of permafrost in the Kara shelf is reconstructed for the past 125 kyr. The work includes zoning of the shelf according to geological history, compiling sea-level and ground temperature scenarios within the distinguished zones, and forward modeling to evaluate the thickness of permafrost and the extent of frozen, cold and unfrozen rocks. The modeling results are correlated to the available field data and are presented as geocryological maps. The formation of frozen, cold, and unfrozen rocks of the region is inferred to depend on the spread of ice sheets, sea level, and duration of shelf freezing and thawing periods.

II.—The Recent Geological History of the Baltic and Scandinavia and its importance in the Post-Tertiary History of Western Europe

1918 ◽  
Vol 5 (10) ◽  
pp. 451-461
Author(s):  
Henry H. Howorth
Keyword(s):  
Western Europe ◽  
Geological History ◽  
History Of ◽  
The Baltic ◽  
Raised Beaches

Let us now turn to the lessons presented by the Mollusca found in the raised beaches of Norway and Western Sweden.

Pteridophyte success and past biota—a palaeobotanist's approach

1985 ◽  
Vol 86 ◽  
pp. 423-430
Author(s):  
B. A. Thomas
Keyword(s):  
Fossil Record ◽  
Geological History ◽  
Term Survival ◽  
Long Term Survival ◽  
Amount Of Information ◽  
The Past ◽  
History Of

SynopsisThe success of plants which lived in the past should be assessed differently from that of living plants as time is an additional important factor. Success may therefore be judged in one period of time or throughout the whole geological history of the plants.Limitations of the fossil record through plant fragmentation, lack of preservation and incomplete preservation severely restrict the amount of information available. However, accepting these problems, there are four major ways in which plants may be judged: long term survival, repeated specialisation, dominance and adaptability. Examples are given of pteridophytes that exhibit success in these four ways.

scholarly journals Continuous vegetation record of the Greater Cape Floristic Region (South Africa) covering the past 300 000 years (IODP U1479)

2022 ◽  
Vol 18 (1) ◽  
pp. 1-21
Author(s):  
Lydie M. Dupont ◽  
Xueqin Zhao ◽  
Christopher Charles ◽  
John Tyler Faith ◽  
David Braun
Keyword(s):  
South Africa ◽  
Vegetation History ◽  
Modern Human ◽  
Cape Floristic Region ◽  
Human Origins ◽  
The Past ◽  
Modern Human Origins ◽  
Last Glaciation ◽  
History Of ◽  
The Last Glacial

Abstract. The Greater Cape Floristic Region (GCFR) of South Africa is a biodiversity hotspot of global significance, and its archeological record has substantially contributed to the understanding of modern human origins. For both reasons, the climate and vegetation history of southwestern South Africa is of interest to numerous fields. Currently known paleoenvironmental records cover the Holocene, the last glacial–interglacial transition and parts of the last glaciation but do not encompass a full glacial–interglacial cycle. To obtain a continuous vegetation record of the last Pleistocene glacial–interglacial cycles, we studied pollen, spores and micro-charcoal of deep-sea sediments from IODP Site U1479 retrieved from SW of Cape Town. We compare our palynological results of the Pleistocene with previously published results of Pliocene material from the same site. We find that the vegetation of the GCFR, in particular fynbos and afrotemperate forest, responds to precessional forcing of climate. The micro-charcoal record confirms the importance of fires in the fynbos vegetation. Ericaceae-rich and Asteraceae-rich types of fynbos could extend on the western part of the Paleo-Agulhas Plain (PAP), which emerged during periods of low sea level of the Pleistocene.

scholarly journals VI. On the structure and affinities of matonia pectinata, R. BR., with notes on the geological history of the matonineœ

1899 ◽  
Vol 191 ◽  
pp. 171-209 ◽  
Keyword(s):  
Special Interest ◽  
Past History ◽  
Wide Distribution ◽  
Steep Slope ◽  
Geological History ◽  
Malay Peninsula ◽  
The Past ◽  
History Of ◽  
Mountain Side ◽  
Distribution In Europe

In describing an ascent of Mount Ophir—about fifty miles east of Malacca, in the Malay Peninsula—Wallace writes as follows : “ After passing a little tangled jungle and swampy thickets, we emerged into a fine lofty forest, pretty clear of undergrowth, and in which we could walk freely. We ascended steadily up a moderate slope for several miles, having a deep ravine on the left. We then had a level plateau or shoulder to cross, after which the ascent was steeper and the forest denser till we came out upon the “ Padang-Batu,” or stone-field, a place of which we had heard much, but could never get any one to describe intelligibly. We found it to be a steep slope of even rock, extending along the mountain side farther than we could see. Parts of it were quite bare, but where it was cracked and fissured there grew a most luxuriant vegetation, among which the pitcher plants were the most remarkable .... A few Coniferae of the genus Dacrydium here first appeared, and in the thickets, just above the rocky surface, we walked through groves of those splendid ferns, Dipteris Horsfeldii and Matonia pectin, which bear large spreading palmate fronds on slender stems, 6 or 8 feet high. The Matonia is the tallest and most elegant, and is known only from this mountain, and neither of them is yet introduced into our hot-houses.” A sketch of Dipteris and Matonia accompanies this description. Both these ferns are of special interest on account of their rarity and isolation at the present day, and as living representatives of generic types which had a wide distribution in Europe during the Mesozoic epoch. The following pages deal with the structure of Matonia pectinata and with such records of fossil ferns as throw light on the past history of Matonia and closely allied genera.

scholarly journals Recent Glacial History of an Alpine Area in the Colorado Front Range, U.S.A.: II. Dating the Glacial Deposits

1968 ◽  
Vol 7 (49) ◽  
pp. 77-87 ◽  
Author(s):  
James B. Benedict
Keyword(s):  
Local Development ◽  
Colorado Front Range ◽  
Front Range ◽  
Glacial History ◽  
Glacial Deposits ◽  
Radiocarbon Dates ◽  
The Past ◽  
Rhizocarpon Geographicum ◽  
History Of ◽  
Mountain Glaciation

AbstractRecent glacial deposits in the Indian Peaks area of the Colorado Front Range have been dated lichenometricaily, using a growth curve developed locally forRhizocarpon geographicum. Radiocarbon dates, where available, tend to support the lichen chronology. Three distinct intervals of glaciation, each consisting of several minor pulsations, have occurred in the area during the past 4500 years. The earliest advance (Temple Lake Stade) is dated at 2500–700 b.c. A later advance (Arikaree Stade) began in about a.d. 100 and ended in a.d. 1000. The most recent advance (Gannett Peak Stade) is dated at a.d. 1650–1850. It remains to be seen whether the Arikaree Stade was purely a local development or whether glaciers were advancing elsewhere in the cordilleran region during this interval. Alluviation on the plains east of the Colorado Front Range seems to have occurred during the waning stages of mountain glaciation.

scholarly journals Gaseous Components in the Atmosphere and the Historic Record Revealed by Ice Cores

1985 ◽  
Vol 7 ◽  
pp. 54-59 ◽  
Author(s):  
B. Stauffer ◽  
H. Oeschger
Keyword(s):  
Special Interest ◽  
Low Temperatures ◽  
Direct Method ◽  
Ice Cores ◽  
Atmospheric Composition ◽  
Ice Formation ◽  
The Past ◽  
Last Glaciation ◽  
History Of ◽  
Historic Record

The composition of air in bubbles of ice reveals important information on the composition of the atmosphere at the time at which the ice was formed. The enclosed air has essentially an atmospheric composition if the ice formation occurred by dry sintering of snow and firn at low temperatures. The history of atmospheric CO2 concentration is of special interest due to its present increase and its climatic implications. Currently, CO2 analysis of air extracted from ice cores seems the best and most direct method of determining the natural CO2 concentration before 1950 and possible pre-industrial variations. Analyses of ice samples representing the past 40 ka show that there were significant changes in concentration of atmospheric CO2 at the end, and probably during part, of the last glaciation. δ13C measurements on CO2 extracted from ice cores can indicate possible mechanisms causing these changes in the concentration of atmospheric CO2.

scholarly journals Gaseous Components in the Atmosphere and the Historic Record Revealed by Ice Cores

1985 ◽  
Vol 7 ◽  
pp. 54-59 ◽  
Author(s):  
B. Stauffer ◽  
H. Oeschger
Keyword(s):  
Special Interest ◽  
Low Temperatures ◽  
Direct Method ◽  
Ice Cores ◽  
Atmospheric Composition ◽  
Ice Formation ◽  
The Past ◽  
Last Glaciation ◽  
History Of ◽  
Historic Record

The composition of air in bubbles of ice reveals important information on the composition of the atmosphere at the time at which the ice was formed. The enclosed air has essentially an atmospheric composition if the ice formation occurred by dry sintering of snow and firn at low temperatures. The history of atmospheric CO2 concentration is of special interest due to its present increase and its climatic implications. Currently, CO2 analysis of air extracted from ice cores seems the best and most direct method of determining the natural CO2 concentration before 1950 and possible pre-industrial variations. Analyses of ice samples representing the past 40 ka show that there were significant changes in concentration of atmospheric CO2 at the end, and probably during part, of the last glaciation. δ13C measurements on CO2 extracted from ice cores can indicate possible mechanisms causing these changes in the concentration of atmospheric CO2.

scholarly journals Recent Glacial History of an Alpine Area in the Colorado Front Range, U.S.A.: II. Dating the Glacial Deposits

1968 ◽  
Vol 7 (49) ◽  
pp. 77-87 ◽  
Author(s):  
James B. Benedict
Keyword(s):  
Local Development ◽  
Colorado Front Range ◽  
Front Range ◽  
Glacial History ◽  
Glacial Deposits ◽  
Radiocarbon Dates ◽  
The Past ◽  
Rhizocarpon Geographicum ◽  
History Of ◽  
Mountain Glaciation

AbstractRecent glacial deposits in the Indian Peaks area of the Colorado Front Range have been dated lichenometricaily, using a growth curve developed locally for Rhizocarpon geographicum. Radiocarbon dates, where available, tend to support the lichen chronology. Three distinct intervals of glaciation, each consisting of several minor pulsations, have occurred in the area during the past 4500 years. The earliest advance (Temple Lake Stade) is dated at 2500–700 b.c. A later advance (Arikaree Stade) began in about a.d. 100 and ended in a.d. 1000. The most recent advance (Gannett Peak Stade) is dated at a.d. 1650–1850. It remains to be seen whether the Arikaree Stade was purely a local development or whether glaciers were advancing elsewhere in the cordilleran region during this interval. Alluviation on the plains east of the Colorado Front Range seems to have occurred during the waning stages of mountain glaciation.

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