Burgsvik Beds - Correlation

Correlation

Mainly due to the inhomogeneous nature of shoreline deposits, lateral variation is intense throughout the Burgsvik beds, making correlation difficult (Laufeld 1974). However, using freshly available borehole data, Manten (1971) was able to further sub-divide the Burgsvik beds into 3 members, illustrated above. The upper bed can be recognised across the entire outcrop belt, varying slightly along strike, and has a distinctive lower contact. The lower bed, however, is easily eroded and rarely exposed. To further complicate the matter, the depositional area was being continually provided with sediment — and thus filling up — from the north west. As bioherm detritus and terrigenous infill accumulated, the coast prograded, and the reef zone advanced in front of it to the south west. This pattern is complicated further by sea level changes, making precise interpretation troublesome, to say the least (Laufeld 1974).

Correlation to units elsewhere in the world is aided by the high-resolution conodont data available; the beds are in the Ozarkodina snajdri conodont subdivision of the Pseudomonoclimacis latilobus graptolite zone, which is also well displayed in, for example, Estonia (Jeppsson et al. 1994, Jeppsson & Männik 1993).