Taihu Lake, often likened to a Buddha's hand in shape, serves as the heart of the water network in southern China. It is rich in resources and has nurtured the lives of people in its basin for centuries, earning the title of 'the cradle of Wu and Yue.' Throughout history, poets and scholars have been captivated by its beauty, leaving behind many famous verses. With its picturesque scenery and abundant produce, the areas surrounding Taihu Lake, including the intricate river networks of the Yangtze River Delta, have long been known as a land of fish and rice in China. The hills surrounding Taihu produce famous teas like Biluochun and the region's red oranges, which were once tributes to the imperial court. Among the diverse aquatic products, the Taihu silver fish, known for its translucent body and tender flesh, is a delicacy often served at banquets.
However, despite its stunning landscapes and grandeur, the origins of Taihu Lake remain a topic of ongoing debate.
As early as the 20th century, Chinese geographer Ding Wenjiang and foreign scholar Heidenshirm suggested that the lake was formed due to sedimentation from the Yangtze River. They theorized that 5,000 years ago, Jiangyin was a coastline, and the area now known as Taihu was part of the sedimentation zone of the Yangtze River, marking the initial theoretical description of the lake's origins.
By the 1930s, the discovery of lacustrine and marine sediment in the lake area led to a more mature and systematic understanding of Taihu's formation. Notable geographers like Zhu Kezhen and Wang Huzhen proposed the lagoon theory, which has since been expanded upon. In 1941, German researcher Feishengmeng suggested that the coastline in the 1st to 3rd centuries AD extended through areas like Taicang, Jiading, and up to Hangzhou Bay. Subsequent carbon-14 dating of shell fragments found at the Maqiao cultural site confirmed that the area was part of an ancient coastline dating back 6,000 years.
Professor Chen Jiyu from East China Normal University, among others, has further developed the lagoon theory based on previous research, arguing that the accumulation of sediment brought by the Yangtze River led to the formation of sandbars that eventually enclosed the ancient Taihu, creating a lagoon. Over time, continuous sedimentation isolated this lagoon from the sea, resulting in the formation of various lakes, with Taihu being the largest.
In recent years, ongoing studies of the geological, geomorphological, hydrological, archaeological, and literary aspects of the Taihu region have raised questions about the lagoon theory. Researchers have found evidence of Neolithic sites and ancient biological fossils beneath the peat layers in the heart of Taihu, suggesting that much of the Taihu plain was originally land, allowing ancient inhabitants to thrive there.
It is speculated that around 6,000 to 10,000 years ago, the Taihu area was a flat plain where people lived. Due to its low elevation, it eventually accumulated water and formed a lake, flooding the homes of its residents before they could evacuate.
The formation of this depression is believed to be linked to tectonic movements. The Taihu region may have been a zone of continuous subsidence, where water from all directions could not drain away, naturally forming a lake. While the 'plain submergence theory' has not gained widespread recognition, a new hypothesis has emerged. Recently, a group of young geologists has proposed that a massive meteorite may have struck the area, creating Taihu Lake.
They hypothesize that the impact of this meteorite generated immense energy, equivalent to the explosion of billions of tons of TNT or the energy of 10 million atomic bombs detonated over Hiroshima.
The proponents of the 'meteorite impact' hypothesis have provided several pieces of evidence: First, the external contour of Taihu shows a significant inward indentation in the northeast, with a fragmented shoreline, while the southwest protrudes outward with a smooth, circular arc resembling meteorite craters found on other continents. Second, researchers have noted a remarkable regularity in the fracturing of rock layers around Taihu, with many fractures in the northeast and compressive fractures in the southwest, suggesting a massive impact from the northeast. Third, they have discovered complex angular gravel around Taihu, which exhibits signs of metamorphism due to impact, along with cosmic dust and molten glass, materials typically formed by meteorite impacts.
Based on this evidence, they infer that the meteorite struck from the northeast, causing radial fractures in the southwest and tension fractures in the northeast. The immense force of the impact shattered rocks, leading to the formation of mixed angular rocks and impact metamorphism.
Currently, there is no consensus on the origins of Taihu, but these diverse perspectives contribute to further investigation and research. As exploration continues, it is believed that the mystery of Taihu's origins will eventually be unveiled.
