Belemnite Marl	Black Ven Marl	Down Cliff Sands	Eype Clay Bed
Green Ammonite Bed	Junction Bed	Shales with Beef	Thorncombe Sands	Three Tiers Bed

Shales with Beef

Overview

Originally known as the Lower Black Ven Beds.

The Shales with Beef (averaging 22m) formation consists of shale beds interspersed with thin beds of fibrous calcite (known as beef, it is fibrous Calcium Carbonate [Calcite] with a cone-in-cone structure). These beef beds are laterally discontinuous; they do not form continuous sheets within the shales.

An outcrop of Beef.

The Shales with Beef  bed is mostly found at sea level to the west of Charmouth, under Black Ven, where they overlay the Blue Lias (originally known as the Lyme Regis Beds). This bed forms intermittent sloping shore platforms or foreshore ledges that are revealed at low tide.

Raffey's Ledge, formed from Beds 73a73g.

The entire formation can be subdivided into two informal members: a lower marl member that measures some 12m thick, which includes beds 54 to 73u, of which the Alcinoe Bed (70c) is the best known. The blue grey marls of this member all exhibit the conchoidal fracturing lines when broken. The upper member is some 10m thick and comprises of beds 74a to 75b. These beds normally consist of brown bituminous paper shales with occasional beds of beef. Fossils in both of these members are poorly preserved, except for those found inside calcareous nodules or limestone beds. The normal horizontal bedding plane is contorted in places due to more recent deformation.

Little Ledge Reef, formed from Beds 74a.

Towards the top of the cliff near to the seafront steps, can be seen the most noticeable horizon, the Birchi Nodule Bed (Bed 75a), [originally these nodules were known as 'Firestone Nodules'].

Exposures

Shales with Beef as found between Lyme Regis and Charmouth:

Fossils

Common ammonites including Arnioceras, Coroniceras  (Crown Ammonite) and Cymbites, teeth and bones of Ichthyosaurs and many other reptiles can be found here. Also found is this division are the fossilised remains of the lobster species Hoploparia longimana.

Hoploparia longimana. 

At the western end of Black Ven (away from Charmouth and towards Lyme Regis), the lower levels of the Shales with Beef can be found. The lowest 12m are blue grey conchoidal marls containing ammonites Arnioceras  and Euagassiceras . Also seen is Little Ledge (Bed 74a), a 20cm limestone with beef and marl bands. Above this bed and up to the Birchi Nodules, the ammonites Arnioceras, Caenisites turneri and Cymbites  are common. Fine specimens of Microderoceras birchi ammonite are found towards the top of the division and in the Birchi Nodule Bed, [originally known as 'White Ammonites' and 'Tortoise Ammonites'].

Microderoceras birchi.

Zones, subzones, beds and fossils

Beds, geology and fossils

Bed	Name	Geology	Fossils found
75b	Bed 75b sitting between the higher Birchi Tabular of the Black Ven Marl, and the lower Birchi Nodular Bed.
75a	Birchi Nodular Bed [Birchi Nodules sometimes called Cement Stones or Firestone Nodules]	Lenticular limestone nodules	Microderoceras birchi
74w
74v
74u
74t
74s
74r		Double band of beef
74q		Light shale and clay
74p		Tabular or lenticular limestone
74o
74n
74m
74l
74k
74j
74i
74h
74g
74f	Hartmanni Bed (Black Arnioceras Bed)	Tabular limestone	Arnioceras
74e		Light shale and clay
74d	Brooki Bed	Lenticules of limestone	Arietites brooki
74c		Shales with beef
74b		Shales with beef
74a	Little Ledge	Brown bituminous paper shales with occasional beds of beef	Forms Little Ledge
73u		Friable marl
73t		Friable marl
73s		Friable marl
73r		Friable marl
73q		Friable marl
73p
73o
73n
73m
73l
73k
73j
73i
73h
73g	Reef 20 [top]	Double seam of beef	Forms Raffey's Ledge
73f
73e
73d
73c
73b
73a	Reef 20 [bottom]	Double seam of beef

For earlier 'Blue Lias' beds, look here 

Photographs

The Shales with Beef divisions are best seen on the Black Ven cliff face
to the west of Charmouth.

The Shales with Beef and its recent 'capping' are eroding
away to the west of Charmouth.

The relationship between the lower Birchi Nodular Bed (bed 75a) in this division, and
the higher Birchi Tabular Bed (Bed 76a) , from the Black Ven Marl division.