The cause of major lake level changes during the evolution of Lake Van (Anatolia): internal (tectonic-volcanic) vs. external (climate) forcing

主要湖平面变化的成因在该湖的演化过程中。600 ka old（ca.）220 m钻孔沉积物，包括约25%（最高）500)原生和改造的火山岩）断层约束的货车湖（安纳托利亚）是有争议的，大多数解释援引气候变化。我建议，构造因素是一个合理的替代解释重复的主要湖泊水位变化高达600米（！）。构造型货车盆地的地球动力学活动至少有600 ky。 例如，2011年的一次大地震造成600人死亡，并在湖盆造成重大断层位移。这里提出的假设将测试高分辨率测年和纹理火山灰分析在四个深度范围内的主要湖泊水位变化的间隔。来源于活跃的亚碱性Süphan和过碱性Nemrut火山的改造火山灰的纹理，其活动侧翼延伸到深湖盆，允许明确的来源识别，同时包含大量关于改造地点和机制的信息。改造的火山岩-特别是在地震记录的主要湖泊水位变化的间隔常见-将以高分辨率进行采样，并详细分析纹理和成分。我们将定义诊断标准，允许区分原位返工远场底部运输过程，并将诊断返工纹理与一系列水深以及快速与缓慢的深度变化率相关联。这种以过程为导向的火山岩内部再加工分析是新颖的，将有助于世界各地的火山岩专家探索火山岩再加工的解释潜力。主要的湖平面变化将通过斜长岩的40 Ar/39 Ar单晶定年来精确定年。将湖平面剧烈变化间隔的详细年龄结构与定年和间接推断的构造过程（例如，阿赫拉特海脊-Halepkalesi线性构造的上升）进行比较。我们的目标是建立货车系统的改造火山灰在构造活跃的湖盆，经历了主要的湖泊水位和气候变化的高度可变的沉积模式的广泛应用的模型。

The origin of major lake level changes during the evolution of the ca. 600 ka old (ca. 220 m drilled sediments including ca. 25% (up to ca. 500) primary and reworked tephras) fault-bound Lake Van (Anatolia) is in dispute, most interpretations invoking climate changes. I propose that tectonic factors are a plausible alternative to explain repeated major lake level changes by up to 600 m (!). The tectonic Van Basin has been geodynamically active for a minimum of 600ky. For example, a major earthquake in 2011 resulted in 600 fatalities and significant fault-displacements in the lake basin. The hypothesis presented here will be tested by high-resolution dating and textural tephra analysis at four depth ranges of major lake level change intervals. Textures of reworked tephra sourced in active subalkaline Süphan and peralkaline Nemrut volcanoes, their active flanks extending into the deep lake basin, allow unambiguous source identification while harboring much information on reworking sites and mechanisms. The reworked tephras – particularly common in the intervals of seismically documented major lake level changes – will be sampled at high resolution and analyzed texturally and compositionally in detail. We will define diagnostic criteria that allow to distinguish in-situ reworking from far-field bottom-transport processes and to correlate diagnostic reworking textures to a range of water depths as well as to rates of fast vs. slow depth changes. Such process-oriented analysis of reworked intralake tephras is novel and will aid lake tephra specialists worldwide in exploring the interpretative potential of reworked tephras. Major lake level changes will be precisely dated by 40Ar/39Ar single crystal dating of anorthoclase. This detailed age structure of drastic lake level change intervals will be compared to dated and indirectly inferred tectonic processes (e.g. rise of Ahlat Ridge-Halepkalesi lineament). Our goal is to establish the Van system as a model for broad applications of highly variable depositional modes of reworked tephra in tectonically active lake basins that have experienced major lake level and climate changes.