i 4 SHELVE DISTRICT 



Meadowtown Beds, first occurs in Morocco in the Lower Caradocian part of the 

 Ktaoua Formation. 



The greater diversity of post-Rorrington brachiopod faunas affords an opportunity 

 to apply Bancroft's Caradocian stages (1945) to the younger Shelve formations and 

 thereby effect a correlation with the classic sections of E. Shropshire. 



The Spy Wood Grit, with Harknessella cf. subplicata, Horderleyella cf. plicata, 

 Salopia cf. salteri and young specimens of Heterorthis, may be correlated with the 

 Coston Beds (Dean 1958 : 218). The latter also contain undescribed Bicuspina, 

 small Dalmanella, Glyptorthis, and Sowerbyella, which may prove to be conspecific 

 with those found in the Shelve area. Further afield in Wales, the additional pre- 

 sence of Platystrophia cf. major, Skenidioides cf. costatus and Salacorthis suggests 

 contemporaneity with the early Caradocian faunas of the Arenig district and 

 Anglesey (Whittington and Williams 1955 ; Bates 1968), and W. Carmarthenshire 

 and Pembrokeshire (R. Addison pers. comm.). 



The Aldress Shales are less decisively dateable because the pre-Soudleyan bra- 

 chiopods of E. Shropshire are largely undescribed. But the occurrence of Sower- 

 byella cf . sericea permixta is an indirect link through its first appearance within the 

 Nant Hir Mudstones of the Bala district (Bassett, Whittington & Williams 

 1966 : 263-264) and suggests that the formation is at least Harnagian in age. 



The relative richness of the Hagley and Whittery faunas is in keeping with their 

 identification as part of an evolving Nicolella association (Williams 1973 : 242). 

 This association is known to have occupied the Anglo-Welsh Basin sporadically 

 throughout Caradocian times, being prevalent in the Costonian Derfel Limestone and 

 Longvillian Gelli-grin Calcareous Ashes of the Bala district (Williams 1963 : 341) 

 and the Upper Longvillian to Actonian formations inclusive of E. Shropshire (Dean 

 1958 : 221-224). Consequently the Shelve assemblages appear to be partly an 

 anachronistic blend of earlier and later forms. Thus Caeroplecia, Palaeostrophomena, 

 Platystrophia and Salopia are also known from the Derfel Limestone although they 

 are represented by different species, but another distinctive member of the associa- 

 tion, Dolerorthis tenuicostata, is not. In contrast to these similarities, Nicolella 

 actoniae (or a subspecies), Onniella ostentata and Sowerbyella sericea are known from 

 Longvillian successions in N. Wales and/or E. Shropshire. Finally Bicuspina and 

 Reuschella are unknown from pre-Soudleyan strata and Kiaeromena cf. kjerulfi and 

 Leptaena ventricosa first appear in the Soudleyan Allt Ddu Mudstones. Indeed, 

 bearing in mind the extraordinary range of N. actoniae including its occurrence in the 

 Cautleyan Portrane Limestone (Wright 1964 : 165), and the complex relationship 

 among the Sowerbyellas of N. Wales which are mainly closely related to S. sericea, 

 the Hagley and Whittery brachiopod assemblages are most likely to be Soudleyan 

 in age. 



Like the older brachiopod assemblages, the Caradocian faunas of Shelve contain 

 very few taxa of use in establishing even a tentative correlation with the biostrati- 

 graphic successions of other provinces. Only the Caradocian rocks of Bohemia and 

 Morocco have yielded faunas with an overall similarity, although the majority of 

 common elements again first appear in demonstrably younger rocks than in Shrop- 

 shire in Bohemia (Havlicek and Vanek 1966 : 53-57). Heterorthis, Horderleyella, 



