Donggi Cona

Donggi Cona
Lake Donggi Cona with ice cover
Donggi Cona
Location	Qinghai, China
Coordinates	35°17′N98°32′E / 35.283°N 98.533°E / 35.283; 98.533
Catchment area	3,174 km2 (1,225 sq mi)
Basin  countries	China
Surface area	229 km2 (88 sq mi)
Max. depth	90 m (300 ft)
Surface elevation	4,090 m (13,420 ft)

Lake Donggi Cona (also Donggei Cuona or Dongxi Co) is a freshwater lake located 4090 m above sea level at the northeastern Tibetan Plateau.

Geology and water chemistry

The lake basin is a tectonic pull-apart structure situated at the highly active Kunlun fault. It is characterised by a 92 m deep graben structure in the deeper western part of the lake basin, and a more shallow eastern part which is filled up with fluvial sediments.

During different episodes of the last ice age, the lake level was 24 to 57 m lower than today, and the lake was a closed system without outflow. With rising lake levels during the Holocene, an outflow developed ca. 4300 years ago, turning the lake into an open system. ^{[1] [2]}

Since ca. 6800 years, the lake is an oligotrophic freshwater lake, with oxygen supply down to the lake bottom and a mean pH of 8.6. A higher primary productivity than at present and brackish conditions were inferred for the late glacial to mid Holocene period. ^{[3] [4]}

Ecology

The vegetation in the lake catchment consists mainly of alpine meadows dominated by Kobresia , Artemisia , and Poaceae. Dunes on the alluvial plains around the lake are characterised by the occurrence of Salix sp. ^[5]

Literature

1. Dietze, E.; Wünnemann, B.; Diekmann, B.; Aichner, B.; Hartmann, K.; Herzschuh, U.; IJmker, J.; Jin, H.; Kopsch, C.; Lehmkuhl, F.; Li, S.; Mischke, S.; Niessen, F.; Opitz, S.; Stauch, G. (2010). "Basin morphology and seismic stratigraphy of Lake Donggi Cona, north-eastern Tibetan Plateau, China". Quaternary International. 218 (1–2): 131–142. doi:10.1016/j.quaint.2009.11.035. Archived from the original on 2023-12-02. Retrieved 2023-02-21.
2. Opitz, Stephan; Wünnemann, Bernd; Aichner, Bernhard; Dietze, Elisabeth; Hartmann, Kai; Herzschuh, Ulrike; IJmker, Janneke; Lehmkuhl, Frank; Li, Shijie; Mischke, Steffen; Plotzki, Anna; Stauch, Georg; Diekmann, Bernhard (June 2012). "Late Glacial and Holocene development of Lake Donggi Cona, north-eastern Tibetan Plateau, inferred from sedimentological analysis" . Palaeogeography, Palaeoclimatology, Palaeoecology. 337–338: 159–176. doi:10.1016/j.palaeo.2012.04.013.
3. Aichner, Bernhard; Herzschuh, Ulrike; Wilkes, Heinz; Schulz, Hans-Martin; Wang, Yongbo; Plessen, Birgit; Mischke, Steffen; Diekmann, Bernhard; Zhang, Chengjun (2012). "Ecological development of Lake Donggi Cona, north-eastern Tibetan Plateau, since the late glacial on basis of organic geochemical proxies and non-pollen palynomorphs". Palaeogeography, Palaeoclimatology, Palaeoecology. 313–314: 140–149. doi:10.1016/j.palaeo.2011.10.015. Archived from the original on 15 November 2023. Retrieved 21 February 2023.
4. Mischke, Steffen; Aichner, Bernhard; Diekmann, Bernhard; Herzschuh, Ulrike; Plessen, Birgit; Wünnemann, Bernd; Zhang, Chengjun (2010). "Ostracods and stable isotopes of a late glacial and Holocene lake record from the NE Tibetan Plateau" . Chemical Geology. 276 (1–2): 95–103. doi:10.1016/j.chemgeo.2010.06.003.
5. Kürschner, Harald; Herzschuh, Ulrike; Wagner, Dorothea (2005-12-14). "Phytosociological studies in the north-eastern Tibetan Plateau (NW China) A first contribution to the subalpine scrub and alpine meadow vegetation" . Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie. 126 (3): 273–315. doi:10.1127/0006-8152/2005/0126-0273. ISSN   0006-8152.