Maotianshan Shales

Maotianshan Shale
Stratigraphic range: Cambrian Stage 3, Qiongzhusian age local stage
Outcrop of the Maotianshan Shale, site of the discovery of the Chengjiang Biota
TypeMember
Unit ofChiungchussu Formation
Areamultiple 10,000 km2 (3,900 sq mi)
Thickness50 m (160 ft)
Lithology
PrimaryShale
OtherMudstone
Location
Coordinates26°42′N 108°24′E / 26.7°N 108.4°E / 26.7; 108.4
Approximate paleocoordinates28°06′N 154°18′E / 28.1°N 154.3°E / 28.1; 154.3
RegionChengjiang County, Yunnan
CountryChina
Type section
Named forMaotianshan Hill
LocationMaotianshan Hill
RegionChengjiang County, Yunnan
CountryChina

The Maotianshan Shales (帽天山页岩) are a series of Early Cambrian sedimentary deposits in the Chiungchussu Formation or Heilinpu Formation, famous for their Konservat Lagerstätten, deposits known for the exceptional preservation of fossilized organisms or traces. The Maotianshan Shales form one of some forty Cambrian fossil locations worldwide exhibiting exquisite preservation of rarely preserved, non-mineralized soft tissue, comparable to the fossils of the Burgess Shale of British Columbia, Canada. They take their name from Maotianshan Hill (Chinese: ; pinyin: Màotiānshān; lit. 'Hat Sky Mountain') in Chengjiang County, Yunnan Province, China.

The most famous assemblage of organisms are referred to as the Chengjiang biota for the multiple scattered fossil sites in Chengjiang. The age of the Chengjiang Lagerstätte is locally termed Qiongzhusian, a stage correlated to the late Atdabanian Stage in Siberian sequences of the middle of the Early Cambrian. The shales date to ≤518 million years ago.

Along with the Burgess Shale, the Maotianshan Shales are remarked as "our best window into the Cambrian 'explosion'", especially on the origin of chordates.