Lake Xiaolongwan




Longgang Volcanic Field

Lake type:


Category: biogenic varves


655 m asl

Length of record:

1500 years

Archive type:

lacustrine sediments

Author of images:

Guoqiang Chu


Chu GQ, Sun Q, Rioual P, Boltovskoy A, Liu Q, Sun PQ, Han JT, Liu JQ, 2008. Dinocyst microlaminations and freshwater “red tides” recorded in Lake Xiaolongwan, northeastern China. Journal of Paleolimnology, 39: 319-333.

Link to reference or DOI:

Dinocyst varve from Lake Xiaolongwan, northeastern China, consisting of light- and brown-colored laminae in the thin sections. The brown-colored layer is composed mainly of dinoflagellate cysts. The grey-colored layer consists of other organic (plant detritus, diatoms, chrysophyte cysts) and clastic matter. A: Flatbed scan of a thin section; B: Detail of laminations from the marked area in A analysed microscopically with transmitted light; C: Enlarged detail of B with transmitted light. > max. resolution

Scanning electron microscopic image of dinoflagellate cysts in Lake Xiaolongwan. A: Cyst showing antapical archeopyle; B: Detail of cyst wall, showing very fine ornamentation in the surface; C: Cyst showing paraplate structure, similar to the theca of Peridinium inconspicuum. D: View of the large archeopyle; E: Cyst with large archeopyle and impressed structure; F: Cyst showing a paraplate structure. > max. resolution