Latest Issue

Journal of Geography (Chigaku Zasshi), 2020 Vol.129 No.3

2020 Vol.129 No.3

Lake Khubsugul in Northern Mongolia: Summer View from a Hill to the West

Lake Khubsugul, a high-altitude (1645m above sea-level) fresh-water lake in northern Mongolia adjacent to the Russian border, is the second largest lake in Mongolia, extending ca. 140km N–S and ca. 35km E–W. Its name, Khubsugul or “blue water” in the local language, derives from its maximum depth of 262m and high water transparency. Due to its high latitude and altitude, the lake is totally frozen during winter, allowing no human activity around it in the past, with the exception of reindeer farming. In contrast, summer tourism has become extremely popular recently with winter sports now becoming trendy, either. Even in mid-August, a snow blizzard welcomed us during the morning immediately after taking this photo under a blue sky. This convinced us of a rare alleged sighting of a snow leopard in the neighboring mountains.
 Lake Baikal, which is much larger, is located ca. 200km ENE in southern Siberia. These two lakes were formed together as N–S trending rifted basins during the late Cenozoic continental extension in central Asia. Lake Khubsugul is thought to have formed in the late Neogene to early Quaternary, but details have not yet been revealed. Mountains, at over 3000m-high to the west, display rugged, snow-covered landscapes even in summer, and are almost identical to those of the European Alps. Precambrian to Lower Cambrian sedimentary rocks penetrated by Paleozoic granitoids in these mountains record the geotectonic history of the Central Asian orogenic belt, in which several continental blocks (Siberia, North China, Tarim, etc.) successively collided or amalgamated with each other, destroying plural oceans in between.


(Photograph & Explanation: Yukio ISOZAKI)


Original Articles

Reconstruction of Ice Sheet Retreat History
 at Skarvsnes, Southern Part of the Soya Coast, East Antarctica,
 Based on Glacial Landforms and Surface Exposure Ages

Moto KAWAMATA, Yusuke SUGANUMA, Koichiro DOI,
Takanobu SAWAGAKI and Akihisa HATTORI

Journal of Geography (Chigaku Zasshi), 2020, 129(3), 315.

DOI:10.5026/jgeography.129.315

Variations in the Proportions of High Schools
 Offering Basic and Advanced Earth Science Classes
 in Prefectures throughout Japan

Kohei YOSHIDA and Hideo TAKAGI

Journal of Geography (Chigaku Zasshi), 2020, 129(3), 337.

DOI:10.5026/jgeography.129.337

Correlation between a Tephra Bed from Deep (2038m) Underground below Chiba City,
 and Kd48 in the Lowermost Kiwada Formation (Lower Pleistocene)
 on the Boso Peninsula

Masayuki UTSUNOMIYA, Kiyohide MIZUNO, Tomonori NAYA,
Kentaro OMURA and Masashi NAGAI

Journal of Geography (Chigaku Zasshi), 2020, 129(3), 355.

DOI:10.5026/jgeography.129.355

Examination of the Relationship between the Ukinuno and Sakate Tephras
 from Sambe Volcano, Southwest Japan

Seiji MARUYAMA, Tohru YAMASHITA, Akira HAYASHIDA,
Takafumi HIRATA and Tohru DANHARA

Journal of Geography (Chigaku Zasshi), 2020, 129(3), 375.

DOI:10.5026/jgeography.129.375

Secular Changes in Fore-arc Sandstones and Their Provenance
 in Cretaceous Southwest Japan: U‒Pb Dating of Detrital Zircons

Ryo HASEGAWA, Yukio ISOZAKI,
Atsushi YAMAMOTO and Yukiyasu TSUTSUMI

Journal of Geography (Chigaku Zasshi), 2020, 129(3), 397.

DOI:10.5026/jgeography.129.397

Short Article

Significance of Introducing Ecotourism
 in Areas Surrounding Tanigawadake and Problems

Hiroaki NAKAOKA

Journal of Geography (Chigaku Zasshi), 2020, 129(3), 423.

DOI:10.5026/jgeography.129.423