The Sandbian is the first stage of the Upper Ordovician. It follows the Darriwilian and is succeeded by the Katian. Its lower boundary is defined as the

first appearance datum First appearance datum (FAD) is a term used by geologists and paleontologists to designate the first appearance of a species in the geologic record. FADs are determined by identifying the geologically oldest fossil discovered, to date, of a partic ...

of the

graptolite Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian ( Miaolingian, Wuliuan) through t ...

species '' Nemagraptus gracilis'' around million years ago. The Sandbian lasted for about 5.4 million years until the beginning of the Katian around million years ago.

Naming

The name Sandbian is derived from the village Södra Sandby (

Lund Municipality Lund Municipality () is a municipality in Scania County, southern Sweden. Its seat is the city of Lund. As most municipalities in Sweden, the territory of municipality consists of many former local government units, united in a series of amalg ...

Skåne County Skåne County ( ), sometimes referred to as Scania County or just Scania in English, is the southernmost Counties of Sweden, county, or , of Sweden, mostly corresponding to the traditional Provinces of Sweden, province of Scania. It borders th ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

). The name was proposed in 2006.

GSSP

The

GSSP A Global Boundary Stratotype Section and Point (GSSP), sometimes referred to as a golden spike, is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. ...

of the Sandbian is the Fågelsång section () at Sularp Brook, east of

Lund Lund (, ;"Lund"
(US) and ) is a city in the provinces of Sweden, province of Scania, southern Swed ...

(

Skåne Scania ( ), also known by its native name of Skåne (), is the southernmost of the historical provinces of Sweden, provinces () of Sweden. Located in the south tip of the geographical region of Götaland, the province is roughly conterminous w ...

). It is an outcrop of

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

and

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from ''shale'' by its lack of fissility.Blatt, H., and R.J. Tracy, 1996, ''Petrology.'' New York, New York, ...

. The lower boundary of the Sandbian is defined as the

species'' Nemagraptus gracilis'' in that section.

References

. Ordovician geochronology {{ordovician-stub