Guanling Fm

Synonym: Kuanling Fm

Lithology and Thickness:

The bottom of the lower Songzikan section (member) is yellowish green glassy tuff (mung bean or "Green Bean" rock), generally 1 to 3 m thick, and the lower part is gray and yellowish gray medium-thick bedded fine-grained dolomite, gray dolomite and dolomitic tuff, sometimes with conglomerate structure, and the middle and upper part is purple-red, gray-green, dark gray and other miscellaneous sandy clay rocks, calcareous clay rocks interspersed with muddy dolomite and marl, etc. The upper Lion Mountain section (member) is gray and dark gray thin to The upper part of Lishan section (member) is dominated by gray and dark gray thin- to thick-bedded tuffs, creeping conglomerate tuffs and marl, with yellow-brown muddy dolomite and calcareous shale in the middle. The thickness is 108 to 920 m.

Lithology-pattern: Sandy claystone

Relationships and Distribution:

Lower contact:

At the bottom, the "Green Bean Rock" is in integrated contact with the underlying Yongningzhen Fm

Upper contact:

It is in conformable contact with the overlying Yangliujing Fm. The first appearances of dolomite is the sign of that boundary.

Regional extent:

This group is a semi-closed shallow or saline marine sediment, distributed in northwest, central and southwestern Jiangxi, and along the eastern part of Yunnan, and is fully exposed, but the thickness varies greatly. In other areas, the upper part suffers from denudation and is not fully preserved.

GeoJSON:

Fossils:

It is rich in bivalve fossils, and the Costatoria goldfussi mansuyi-Leptochondria illyrica assemblage zone can be built; the Shizishan section (member) also produces Progonoceratites sp.

Age:

Anisian

Age span:

Beginning stage: Anisian

Fraction up in beginning stage: 0.0

Beginning date (Ma):

Ending stage: Anisian

Fraction up in ending stage: 1.0

Ending date (Ma):

Depositional setting:

This formation is a semi-closed shallow or saline marine sediment, distributed in central Jiangxi, northwestern Jiangxi, southwestern Jiangxi, and along the eastern part of Yunnan, and is fully exposed, but the thickness varies greatly. In other areas, the upper part suffers from denudation and is not fully preserved.

Depositional-pattern:

Additional Information

In 1944, Xu Deyou and Chen Kang changed the name to "Ani Sikh Formation" (Guanling System). In 1962, Yin Hongfu used the Guanling Formation to represent the Middle Triassic sediments and divided it into four sections (members) from bottom to top: the Maocaopu section, the Songzikan section, the Lishan section and the Yangliujing section. In 1976, the stratigraphic group of the Guizhou Stratigraphic and Paleontological Task Force redefined the lithospheric range of the Guanling Formation. In 1976, the stratigraphic group of Guizhou Stratigraphic Paleontological Task Force redefined the rock stratigraphy of the Guanling Formation as "Green Bean Rock", including the above-mentioned Songzikan section, Lishan section and Yangliujing section (members), which is of Middle Triassic Anisian age. The Southwest Regional Stratigraphy, Guizhou Branch (1977) and the Guizhou Bureau of Geology and Mines (1987) also separate the "Yangliujing section" into a separate group. Wang Zunzhou et al. (1992) basically followed this meaning, but advocated that the bottom boundary of this group should be raised from the "Green Bean Rock" to the bottom of the muddy mudstone layer by tens of meters. The meaning of "Stratigraphic Table" (1977) and Guizhou Geological and Mining Bureau (1987) is used in the present Code. The Songzikan member is derived from the Songzikan Shale by Ding Wenjiang (1928), and the named section is located in Songzikan, 2.5 km north of Zunyi City, Guizhou. The Shizishan member is derived from the "Shizishan Limestone" of Wang Yu (1944), and the named section is located in Shizishan near Zunyi, Guizhou. This limestone was once called the "Sanqiao Limestone" by Liu Zhiyuan (1942), but was renamed the "Lishan Formation" by Zhao Jinke and others in 1962.