Bouldery deposits along the Kherlen fault, Central Khentey, Mongolia: implications for paleoseismologyстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 26 января 2022 г.
Аннотация:The assumed Jargalant rockslide is located in Khentey Upland of Mongolia, an area undergoing
active tectonic deformation and seismogenic activity but where geomorphic research
that connects rock slope failure and long-term paleoseismic events has yet to be conducted.
We present the first reconnaissance study on this topic, which demonstrates the possibility
of cosmogenic 10Be dating of landslide-induced bouldery deposits to date the timing
of the assumed seismic events. We performed integrated geomorphic analysis (geomorphic
mapping, topographic profile analysis, and surface trenching) and 10Be surface exposure
dating (boulder and bedrock scar) to document the recurrence interval of the assumed
paleoseismic events by determining the recurrence of rock slope failures in Jargalant River
valley. We identified four geomorphic surfaces and units identified based on their morphology,
the distribution of quartzite boulders, and their ages. The geomorphic units are as
follows: (1) outburst flood fan (S1), (2) remnant landslide-dam deposit (S2), (3) surviving
rockslide body (S3), and landslide scar (S4). Bedrock quartzite outcrops only in the
assumed headscarp, while most of the upland is composed of schist. The average 10Be age
of quartzite boulders of S1 to S3 is 283.4, 138.8, and 48.4 ka, respectively, and that of
the landslide scar (inner and outer edge) are 44.5 and 193.5 ka. Based on the morphology,
depositional characteristics, quartzite provenance, and separated and clustered 10Be
exposure age, we hypothesize that at least three catastrophic rock slope failures could occur
at 283 ka, 138 ka, and 48 ka, likely being triggered by earthquakes associated with active
Kherlen fault.