86 MIDDLE ALBIAN STRATIGRAPHY 



in particular of the eodentatus and lyelli Subzones in this area. The clay facies of the 

 dentatus Zone passes rapidly in the St. Florentin area to a predominately sandy facies 

 characteristic of the succession in the Puisaye-Yonne, Nievre, Cher, indicating the 

 proximity of the Variscan massif of Morvan. In the whole area under consideration 

 the proved sediments of loricatus Zone age represent only the intermedins Subzone 

 and in the Puisaye these are largely remanie. Sediments of lautus Zone age have 

 not yet been detected. 



This area has been studied by many French Cretaceous workers. One of the 

 earliest papers written was by Michelin (1838) on the sequence at Gaty, pres Geraudot 

 (Aube). Leymerie (1841, 1842) then described the Gault in the Aube but, unfortun- 

 ately, d'Orbigny (1841) just antedated Leymerie's description of Ammonites lyelli 

 one of the most characteristic fossils. This was followed by a similar description 

 of the Gault in the Departement of the Meuse by Buvignier (1852). Various papers 

 on individual localities were then published but the next important work before 

 Barrois was that of Ebray (1863) who attempted to coordinate the sequence in the 

 various Departements. 



Barrois made the first attempt to tie in the apparently different sequences of the 

 Boulonnais, Ardennes, and the strip of country from the Meuse to the Nievre (1875). 

 Unfortunately, two very inaccurate attempts were made to correlate the succession 

 in the Aube with that of Folkestone (Price & Delatour in Price 1879 ; 1880 ; 37-40, 

 Jukes-Browne 1900 ; 388-390). The result completely obliterated Barrois's work in 

 English minds, and eventually led to a great deal of uncertainty as to the strati- 

 graphical position of the clays containing Ammonites lyelli in relation to the sequence 

 known in England. This uncertainty was not completely settled even by Spath 

 (e.g. 1926b ; 1943, 722). It was not until Wright & Wright demonstrated the 

 occurrence of Lyelliceras in the ' benettianus ' Subzone in Surrey (1948), and the 

 stratigraphical position more definitely indicated by Casey (1961a) that the question 

 was put beyond doubt in English minds. 



The first general account of the Albian in this area of France to appear after 

 Barrois was a paper by Lemoine (1910). Larcher (1937) subsequently produced a 

 very interesting paper in which the fauna of the broad lithological units were listed 

 accurately for the first time. However, it was not until 1965 that a more detailed 

 picture of the sequence and its facies changes could be obtained. Four very im- 

 portant papers were presented to the Colloque sur le Cretace inferieur held in Lyon in 

 1963. These were published in 1965 and written by : — Larcher, Rat, & Malapris ; 

 P. & J.-P. Destombes ; Marie ; and Ciry, Rat, Malapris & Nicolas. Of these, the 

 paper by P. & J.-P. Destombes is of paramount importance. Recently, Lauverjat 

 (1969) has described the broad lithological sequence and facies changes shown by 

 deep borings through the Chalk along two lines, parallel to the Albian sediment out- 

 crop, from the area of Troyes (Aube) south west to the river Loing ( Yonne) . 



(a) Revigny-sur-Ornain (Meuse) 



Barrois demonstrated (1878), that in the northern part of the Argonne (part of the 

 Departements of the Ardennes, Meuse, and Marne) sediments now included in the 



