- Sularp Brook
Sularp Brook (coord|55|42|49.3|N|13|19|31.8|E), near
Fågelsång ,Skåne ,Sweden , is the location of theGlobal Boundary Stratotype Section and Point (GSSP) which marks the boundary between the Middle and Late epochs of theOrdovician era on thegeologic time scale .The first appearance of the
graptolite "Nemagraptus gracilis" defines the boundary. The rock section consists primarily of dark-grayshale andmudstone , except for a phosphorite marker bed 1.4 m above the GSSP, and was probably deposited at a water depth exceeding 100 m. Drill cores have revealed almost identical stratigraphy across an area several km wide. Due to heating, possibly from an intrusive dike, the stratotype is unfit for dating by magnetic analysis, but this lack is compensated by the diversity of chemostratigraphic and biostratigraphic options.References
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