Isotopic and Petrographic Evidence as a Proxy in Paleoclimatic Reconstructions from Flowstones in Southern Spain

• 作者: Antonio González-Ramón Bartolomé Andreo Concepción Jiménez de Cisneros Cristina Sequero Ian J. Fairchild
• 来源期刊: 地质学期刊(英文)
• 学科: 经济
• 关键词: SPELEOTHEMS Flowstones Fabrics Isotopic Characterization CAVE Paleoclimatic Changes
• 年，卷（期）: 2020,（6）
• 页码范围: 597-611
• 页数: 15页
• 分类号: F42

摘要

Changes in the morphology and mineralogy of speleothems (flowstones) clearly respond to climate-related phenomena, such as drip rate variability and temperature-modulated cave ventilation. Detailed petrographic observations have been coupled with <em><em style="font-family:Verdana;white-space:normal;"><em style="font-family:Verdana;white-space:normal;">δ</em></em></em><sup style="font-family:Verdana;white-space:normal;">18</sup><span style="font-family:Verdana;white-space:normal;">O</span> and <span style="font-size:12px;font-family:Verdana;"><em>δ</em></span><span style="font-size:12px;font-family:Verdana;">¹³C values. Fabrics may show changes related to variations in supersaturation, drip rate or input of detrital particles or organic compounds. Fabrics formed under relatively constant and regular drips (columnar compact, open and elongated) show similar <em>δ</em>¹⁸O and <em>δ</em>¹³C values, which are more negative than those of micrite and microsparite. The combination of internal microstratigraphy studies and isotopic data (<em>δ</em>¹⁸O and <em>δ</em>¹³C) from two flowstones collected from two caves in the north of Almeria province (SE Spain), suggest a spectrum of environmental conditions ranging from wetter to drier periods. Both records constitute a very useful tool for screening and interpreting high-resolution paleoclimate reconstructions.</span>