Glacial stages and post-glacial environmental evolution in the Upper Garonne valley, Central Pyrenees
| العنوان: | Glacial stages and post-glacial environmental evolution in the Upper Garonne valley, Central Pyrenees |
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| المؤلفون: | Marc Oliva, Maria Rosário Fernandes, Luis Felipe Dias Lopes, Pedro Palma, Jesús Ruiz-Fernández |
| المساهمون: | Repositório da Universidade de Lisboa |
| المصدر: | Repositório Científico de Acesso Aberto de Portugal Repositório Científico de Acesso Aberto de Portugal (RCAAP) instacron:RCAAP |
| سنة النشر: | 2016 |
| مصطلحات موضوعية: | Environmental Engineering, 010504 meteorology & atmospheric sciences, Glacial landform, 010502 geochemistry & geophysics, 01 natural sciences, Deglaciation, Environmental Chemistry, Glacial period, Waste Management and Disposal, Geomorphology, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Holocene, Glacier, Glacier morphology, Pollution, U-shaped valley, Moraine, Last Glaciation, Wisconsin glaciation, Physical geography, Central Pyrenees, Upper Garonne, Geology |
| الوصف: | The maximum glacial extent in the Central Pyrenees during the Last Glaciation is known to have occurred before the global Last Glacial Maximum, but the succession of cold events afterwards and their impact on the landscape are still relatively unknown. This study focuses on the environmental evolution in the upper valley of the Garonne River since the Last Glaciation. Geomorphological mapping allows analysis of the spatial distribution of inherited and current processes and landforms in the study area. The distribution of glacial records (moraines, till, erratic boulders, glacial thresholds) suggests the existence of four glacial stages, from the maximum expansion to the end of the glaciation. GIS modeling allows quantification of the Equilibrium Line Altitude, extent, thickness and volume of ice in each glacial stage. During the first stage, the Garonne glacier reached 460 m in the Loures-Barousse-Barbazan basin, where it formed a piedmont glacier 88 km from the head and extended over 960 km 2 . At a second stage of glacier stabilization during the deglaciation process, the valley glaciers were 12–23 km from the head until elevations of 1000–1850 m, covering an area of 157 km 2 . Glaciers during stage three remained isolated in the upper parts of the valley, at heights of 2050–2200 m and 2.6–4.5 km from the head, with a glacial surface of 16 km 2 . In stage four, cirque glaciers were formed between 2260 m and 2590 m, with a length of 0.4–2 km and a glacial area of 5.7 km 2 . Also, the wide range of periglacial, slope, nival and alluvial landforms existing in the formerly glaciated environments allows reconstruction of the post-glacial environmental dynamics in the upper Garonne basin. Today, the highest lands are organized following three elevation belts: subnival (1500–1900 m), nival (1900–2300 m) and periglacial/cryonival (2300–2800 m). |
| وصف الملف: | application/pdf |
| تدمد: | 1879-1026 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6b6e1a0260f1755e22e286fa68f7d48a https://pubmed.ncbi.nlm.nih.gov/28162758 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....6b6e1a0260f1755e22e286fa68f7d48a |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 18791026 |
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