Aleksander Czekanowski

From 1869 to 1875 he made several expeditions to Eastern Siberia. to study the geological structure of Irkutsk province. Between 1869 and 1871 Chekanovski conducted work on the study of Baikal Mountains and Siberian lands from Baikal to Yenisei and Sayan Mountains, and also studied Irkutsk province. In 1869, he defined the Primorsky Range (1728 m), which stretches along the western shore of Lake Baikal, as an independent morphographic unit. In 1871 together with Wiktor Godlewski and Benedykt Dybowski he explored the northern part of the shore of Lake Khövsgöl in Mongolia. His stay in Irkutsk was marked by a number of scientific discoveries that brought him the glory of “one of the outstanding geologists of Russia”. Published in 1872, his monograph on the Irkutsk province was awarded a gold medal, and the collections collected in Ust-Baley formed the basis of the famous work on the Jurassic flora, written by professor Geer of the University of Zurich.

In 1872, Czekanowski proposed to the Geographical Society to explore the area between Yenisei and Lena, which at the time was still a "big white spot" in terms of hyrodgraphy and relief. The company commissioned him to lead a small research expedition lasting two years, to which Ferdinand Ferdinandovich Miller was appointed to its staff as astronomer and physicist. From 1872 to 1875, the two explored Central Siberian Plateau.

The first expedition began in March 26 1873 when Czekanowski went from Irkutsk to the source of the Lena, where he studied the geological structure of the banks of the upper reaches of the Lena and Angara rivers. When the ice drift began on the Angara, physicist Miller and the Nakhalny topographer joined him from Irkutsk. May 12 the group moved in boats along the Angara River to the headwaters Lower Tunguska. Over the three summer months of 1873, travellers traced the entire course of the Lower Tunguska to its mouth, plotting it on a map and determining its length (2989 km). It was the second scientific expedition to the Lower Tunguska after Daniel Messerschmidt (1723). In September 1873, the expedition, having passed the Arctic Circle, reached the Yenisei and by November 5 had returned to Irkutsk. The main result of this expedition was the discovery of a huge trap cover (the Middle Siberian Traps), traced by him along the valley of the Lower Tunguska for over 1900 kilometers. In addition, Czekanowski's “Additional information to the map of the Lower Tunguska River" for the first time described the territory along the river as a plateau – a hill with characteristic table mountains. He had in fact made the scientific discovery of the Central Siberian Plateau and described the relief of its central part.

A new second expedition was hastily prepared, which was to cross the Arctic Circle and conduct research to the still unknown river Olenyok. On 25 December 1873 Czekanowski and Miller left Irkutsk with two local guides travelled to Dolna Tunguska and proceeded on to 63º N, before continuing north-northwest to reach the springs of the river Vilyuy (66°00′N 104°00′E). The journey lasted two months, and finally, in April, the expedition reached the shores Syurungna (Vilyui). After several weeks of exploring the shores of Lake Yakongna, June 6 1874, the expedition reached a fairly significant river. Czekanowski, having decided that it was the Olenyok, however, the local Evenks explained that it was Moyero (the right tributary of the Kotuya from the Khatanga basin), and Olenyok was located to the northeast. From Moyero, the two crossed the hill Bukochan that acts as a low watershed, and crossed to the Oleneok about 150 kilometres below the source, and in July began rafting down on the river on a raft. At the end of September they reached 70º 30` N, and when the river froze they continued downstream with reindeer herds, crossing the Central Siberian Plateau in a northeast direction and reaching the river mouth in early November. Then they returned again to 70º 30` N, ascend one of the right tributaries of Olenyok, crossed watershed and between Olenyok and Lena and descend on the latter to the village of Bulun. From there in Verkhoyansk they reached Yakutsk and in January 1875 returned to Irkutsk. Czekanowski established that there are no high mountains along the Olenyok, and according to his definition, the length of the river was about 2350 kilometres (according to the latest data – 2292 kilometers). Miller was the first to measure the heights of Eastern Siberia.

Organising his third Siberian expedition, A. L. Czekanowski intended to "go along the banks of the Lena to the mouth and, if possible, then go to the mouth of the Olenyok from the sea." He hoped to have time to conduct geological exploration of the banks of the Lena River before the onset of winter, but a short summer frustrated his plans. From a barge Czekanowski conducted an investigation of the banks of the Lena from Yakutsk to Bulun exploring the Lena River for a distance of about 1,200 kilometres (750 mi), from Yakutsk to the mouth to the Eyekit, its left tributary. At first, the path ran along the deep and wide bay of the Eyekit river, and then along the rocky and mountainous watershed area lying between the Lena and the Olenyok and descending along the Kelimyar River to the Olenyok. In this way he discovered a 350 kilometres (220 mi) long ridge (highest point 432 metres (1,417 ft)), which was later named Chekanovski at the suggestion of Edward Toll. From the Kelimyar he traced the course of the Olenyok to its mouth. August 26 from the top of Mount Karanchat they saw the ocean. By the 18 September the expedition was already in Bulun, having safely crossed the frozen Lena. The expedition reached Verkhoyansk by reindeer from where they went through the mountains and tundra reaching Irkutsk on the 20 December 1875.

Thus ended the three expeditions of A. L. Czekanowski, the zoological results of which were recognized as “the richest of all that have ever been undertaken in Siberia. The reports of the expedition, rich in content, being translated into different languages, became the property of science, and the maps compiled by him significantly changed and supplemented the map of Asian Russia. ” He wrote the first reliable data on the geology of this region (1873), the southern course of the Lena and the Olenyok region (1874–75). He also discovered coal and graphite deposits over the Lower Tunguska River.

Upon his return from his last expedition, he received notice that he was amnestied, and returned to St Petersburg, to handle the processing of materials collected by him during the expeditions from the point of view of geography, geology and paleontology.. In the same year, he presented to the Academy of Sciences a project of an expedition in which he set out to geologically explore all the large Siberian rivers in the territory between the Yenisei, Lena, Anabar, Khatanga and Pyasina. However, the expedition's equipment required large sums of money, and the project of Czekanowski met with serious objections. This provoked an exacerbation of his mental disorder and on October 18 (30), 1876 Czekanowski committed suicide by taking a large dose of poison. His materials were not published until 1896 under the title ' Diary of the expedition on the rivers Nizhny Tunguska, Olenek and Lena in 1873 – 1875 "" (St. Petersburg, 1896). His botanical and zoological collections have been the subject of studies by numerous scientists since.