15 comments on “Baitoushan – the volcano with many names

  1. Hi agimarc, Baitoushan is certainly one interesting volcano; thanks for your detective work! Hopefully it does show some activity soon!

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  2. Definitely one of the most difficult large active calderas to visit, most of the research about Changbaishan was published in Chinese or Japanese. Only recently researchers have started publishing in English journals.
    Based on the K-Ar dating published in Chinese, constructions of the base of the trachytic cone started about a million years ago but the main construction of the cone did not start until >600 kyr, and the erupted materials, including trachyte and trachytic pyroclastics, during this stage are known as Baitoushan Formation. Baitoushan Formation is mainly composed of lava flows embedded with pyroclastics, including traychtic welded tuff, breccia and pumice, indicating explosive eruptions. Some of these explosive eruptions were just as strong as Millennium Eruption (946 AD) based on thickness and Middle-Late Pleistocene trachytic tephra layers originated from Changbaishan in the Japan Sea cores. There are more dozen of tephra layers which are chemically correlated with Changbaishan trachyte but distinct from Japan arc or other sources, but their corresponding proximal deposits are not fully explored. Baitoushan Formation are divided into at least three periods based on the embedded paleosol, the final phase of this formation was dated to be as recent as 20 kyr based on K-Ar and 40Ar/39Ar.
    There have been two explosive comenditic eruptions comparable in magnitude after the main construction of the cone. The first one, known as Tianwenfeng period, produced widespread of yellow pumice, but most of its product is eroded and its ignimbrite has never been identified anywhere. The age of this eruption, unfortunately, has not yet reached a consensus. It could be anytime from Late Pleistocene to Mid-Holocene (likely older than 10 kyr though).
    The second explosion, Millennium Eruption, was recently dated to the winter of 946 AD. There is no break in between pumice fallout and flow, but the eruption does have two phases and possibly has a short hiatus in between. The first phase erupted grey-white comenditic pumice with a Plinian plume (25 km) and is immediately followed by the collapse of the plume producing flows covering over 2400km2 on the plain. There is likely a short break lasting from days to months. The second phase started with black-yellow trachytic pumice also with a Plinian plume but less in intensity and is followed by dark trachytic welded tuff (pyroclastic flows) deposited within valleys and the caldera.
    Other Holocene eruptions include a few historical ones and 180 BC and 2160 BC. The 180 BC is questionable and is only reported to be a distal tephra layer discovered in Japan, yet no known proximal deposit could correlate with it. 2160 BC comes from dating a charcoal buried within a limited exposed lag breccia deposit on the north flank of the volcano, but there is also no other product that could be attributed to this eruption. Some Chinese scholars try to correlate the lag breccia with Tianwenfeng period but their connection is very ambiguous.
    Overall, the history of explosive eruptions of Changbaishan is still elusive. International volcanologists are corroborating with Chinese scholars to determine the large eruptions of Changbaishan in the past 86 kyr by carefully examining Changbaishan tephras in the Japan Sea cores. Other scholars are working to obtain high-resolution 40Ar/39Ar dating of Tianwenfeng pumice and to establish the correct stratigraphic sequences.

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