Uintacrinus anglicus Zone

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Base: In southern England, the base of the zone is placed at Friar's Bay Marl 1, and in northern England, a little above marl SY 17 of Whitham (1993). Data from East Anglia is incomplete, but the zone appears to be absent in north Norfolk (perhaps omitted at a non-sequence between the M. testudinarius Zone and the Offaster pilula Zone in the BGS Trunch Borehole [TG 2933 3455]; Wood & Morter, 1994), although it probably extends into southern East Anglia (Wood & Morter, 1994). The zone has not yet been proved in Northern Ireland, although Wilson & Manning (1978) tentatively suggested that it might correspond with the topmost part of the Cloghastucan Chalk, above the Oweynamuck Flint, where Marsupites testudinarius is absent.

Top: In southern England, the top of the zone is placed at the highest of the three Friar's Bay Marls (Young & Lake, 1988), and in northern England, at marl SY 23 of Whitham (1993) (Mitchell, 1995).

Range of index species: In southern England, the range of the index is co-extensive with the nominate zone, but in northern England, where the base of the zone is defined by the last occurrence of Marsupites testudinarius, the index is absent from the lower part of the nominate zone (Mitchell, 1995).

Key fauna:

Brachiopoda: Cretirhynchia exsculpta
Bivalvia: Acutostrea incurva
Pseudoperna boucheroni
Pycnodonte vesiculare
Sphenoceramus (Inoceramus) lingua*
Belemnoidea: Gonioteuthis*
Crinoidea: Uintacrinus anglicus
Echinoidea: Echinocorys tectiformis

(*: common in northern England)

Faunal abundance & preservation: In southern England, the zone is not particularly fossiliferous, the fauna being dominated by rather small and fragmentary fossils. The index species is very inconspicuous, comprising rare dissociated calyx plates. In northern England, the fauna is dominated by vast amounts of the fragmented remains of the long-ranging Sphenoceramus (Inoceramus) lingua (Mitchell, 1995).

Bio-markers: The zone is typically very thin and there is little to distinguish particular horizons within it. In southern England, Young & Lake (1988) show that Echinocorys tectiformis appears in the higher part of the zone. On the basis of the relationship between the occurrences of U. anglicus in northern and southern England, Mitchell (1995) proposed the following lithostratigraphical correlations:

Southern England Northern England
Friar's Bay Marl 1 = SY 18 of Whitham (1993)
Friar's Bay Marl 2 = Daneswood Lower Marl
Friar's Bay Marl 3 = Daneswood Middle Marl
Ovingdean Marl = Daneswood Upper Marl

Age: Early Campanian