古湖泊

古湖泊（英语：Ancient Lake）是指超过一百万年持续有水的湖泊。世界上大部分湖泊水体的历史都不到 18,000 年。超过100万年的古湖泊仅20个 ^[1]。其中有12个年龄超过260万年，其年龄几乎涵盖整个第四纪。古湖泊能继续存在的原因，是由于活跃的板块构造。在板块构造形成的裂谷带中会形成了非常深的湖泊，在自然环境下这些湖泊很难被沉积物填满。由于古湖泊的寿命很长，它们可以被研究作为孤立的演化特征和物种形成的模型。贝加尔湖通常被认为是最古老的湖，表明它已有2500-3000万年的历史^[2]^[3]，而其所根据的证据无争议。扎伊桑湖可能更古老，但其确切年龄具争议性^[4] 。该湖可能起源于白垩纪，至少有6600万年^[5] 最有可能在7000万年左右 ^[6]。另一个具争议性是马拉开波湖，估计有2000-3600万年的历史。在古代，它是一个真正的湖泊，但今天它是咸水湖并直接与大海相连，导致许多人认为它是一个大潟湖或海湾。

古湖泊与年轻湖泊

湖泊有六种主要类型（如下所列）。大多数湖泊的干涸是由于数千年来从河流系带沉积物填充所致。其他影响水位下降的因素包括、蒸发、自然排水和地球物理过程。由于古湖泊处于裂谷带所造成的地堑中，具活跃的地表下沉，与其他湖泊相比，古湖泊的寿命更长。例如，俄罗斯的贝加尔湖，是由贝加尔裂谷带形成的古老湖泊，已有2500-3000万年的历史，深5,387英尺（1,642米）。相较之下，北美五大湖是在冰河期末期由冰川冲刷和融水汇集形成的，已有14,000年的历史，最大深度为200-1,300英尺（60-400 m）。

裂谷湖
土石流和冰坝湖
咸水湖
牛轭湖
火山口湖
冰川湖
冰下湖泊

古湖泊的形成

古代湖泊的形成类似裂谷。形成发生在位于活动裂谷带上的地堑内。地堑是沿着不同的板块边界形成的土地部分，这些板块边界在两个平行板块之间下沉。地堑的位置位于活动裂谷带上方，导致湖底深度不断下降，湖壁高度不断增加。

对演化的重要性

古湖泊能提供资料让科学家研究冰期-间冰期时间的环境变化的机制。由于古湖泊的长存在期和普遍的地理隔离，人们对包括性选择、辐射适应和间断平衡在内的演化特征进行了研究。大多数研究都针对在孤立湖泊中特有动物群和硅藻有关，主要集中在贝加尔湖、里海和非洲五大湖。资料来自河流-湖泊、波动深部（fluctuating profundal）和蒸发岩的组合。本条目是根据英维“tuya” 编译而来

参考文献

^ Free, Christopher (April 23, 2016). "Ancient lakes of the world". Christopher M. Free. Archived from the original (website) on February 9, 2020. Retrieved 20 January 2024. Most of the hundreds of thousands of inland water bodies on our planet are less than 18,000 years old, but a few lakes and inland seas have existed continuously for more than 1 million years. I present a database of the 20 ancient lakes of the world.
^ Lake Baikal – UNESCO World Heritage Centre". 1992–2024. Retrieved 20 January 2024. Situated in south-east Siberia, the 3.15-million-ha Lake Baikal is the oldest (25 million years) and deepest (1,700 m) lake in the world. It contains 20% of the world's total unfrozen freshwater reserve.
^ ^ "Lake Baikal: Protection of a unique ecosystem". ScienceDaily. 26 July 2017. Retrieved 8 March 2018.
^ "The Oldest Lakes in the World". World Atlas. 25 August 2017. Retrieved 8 March 2018.
^ Lucas; Bray; Emry; Hirsch (2012). "Dinosaur eggshell and Cretaceous-Paleogene Boundary in the Zaysan Basin, eastern Kazakhstan". Journal of Stratigraphy. 36 (2): 1376–1382. doi:10.1016/j.proenv.2011.09.220
^ Dorfman, B.F. (2011). "Zaysan-the Only Surviving Cretaceous Lake-May be Lost". Procedia Environmental Sciences. 10 (B): 1376–1382. Bibcode:2011PrEnS..10.1376D. doi:10.1016/j.proenv.2011.09.220.

[”-1] Free, Christopher (April 23, 2016). "Ancient lakes of the world". Christopher M. Free. Archived from the original (website) on February 9, 2020. Retrieved 20 January 2024. Most of the hundreds of thousands of inland water bodies on our planet are less than 18,000 years old, but a few lakes and inland seas have existed continuously for more than 1 million years. I present a database of the 20 ancient lakes of the world.

[”Lake”-2] Lake Baikal – UNESCO World Heritage Centre". 1992–2024. Retrieved 20 January 2024. Situated in south-east Siberia, the 3.15-million-ha Lake Baikal is the oldest (25 million years) and deepest (1,700 m) lake in the world. It contains 20% of the world's total unfrozen freshwater reserve.

[”Leopold”-3] "Lake Baikal: Protection of a unique ecosystem". ScienceDaily. 26 July 2017. Retrieved 8 March 2018.

[”The”-4] "The Oldest Lakes in the World". World Atlas. 25 August 2017. Retrieved 8 March 2018.

[”Lucas”-5] Lucas; Bray; Emry; Hirsch (2012). "Dinosaur eggshell and Cretaceous-Paleogene Boundary in the Zaysan Basin, eastern Kazakhstan". Journal of Stratigraphy. 36 (2): 1376–1382. doi:10.1016/j.proenv.2011.09.220

[”Dorfman”-6] Dorfman, B.F. (2011). "Zaysan-the Only Surviving Cretaceous Lake-May be Lost". Procedia Environmental Sciences. 10 (B): 1376–1382. Bibcode:2011PrEnS..10.1376D. doi:10.1016/j.proenv.2011.09.220.

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