MIDDLE ALBIAN (LOWER GAULT)
Stratigraphy at Folkestone
based on a section at Copt Point

 

Ammonite Zone

Ammonite

Sub-zone

Bed 

Lithology

Meters

LATE ALBIAN

Mortoniceras inflatum (part)

Dipoloceras cristatum (part)

VIII

 

 

MIDDLE ALBIAN

 

Euhoplites lautus

Anahoplites daviesi

VII

mid-grey clay with shell seams containing pyritised fossils and scattered phosphatised fossils

0.84

Euhoplites nitidus

1.54

VI

Lenticles of light grey clay, extensively burrowed with dark grey clay infillings in mid-grey clay

0.305

V

Shelly burrowed mid-grey clay with scattered brown phosphates

0.46 to 0.48

MIDDLE ALBIAN

 

Euhoplites loricatus

Euhoplites  meandrinus

IV

(iii) Abraded black phosphatised nodules and fossils in grey clay

0.025 to 0.05

Dipoloceroides

subdelaruei

(ii) Dark grey shelly clay

0.1

(i) Seam of bivalves, part phosphatised fossils & buff phosphatised nodules

0.025

Dimorphoplites niobe

III

Fawn grey clays with shell seams and partly phosphatised fossils and occasional lenticles of ferruginous marlstone

1.83

Anahoplites intermedius

II

(iv) Dark grey clay black when wet, with seams of crushed & pyritic shells passing at top by lenses of fawn clay into bed III

0.89

(iii) Blackish phosphatic nodules in dark grey clay

0.025

(ii) Dark grey clay, black when wet, with seams of crushed shells

0.38

(i) Crushed and part phos. shelly and irregular phosphatic nodules

0.05

I

(vii) Dark-grey slightly silty shelly clay

1.575

MIDDLE ALBIAN

 

Hoplites (Hoplites) dentatus

Hoplites spathi

(v) Gritty grey clay becoming more glauconitic and gritty downward; sparsely shelly with occasional seams of phosphatic "clots"

1.22

(v) Large phosphatic nodules mainly casts of ammonites in shelly glauconitic loam "dentatus nodule bed"

0.1

Lyelliceras lyelli

(iv) Highly glauconitic loam with few blackish phosphatic nodules

0.1 to 0.18

(iii) Scattered spherical septarian phosphatic nodules

0.05

EARLY ALBIAN

(Part)

 

Douvilleiceras mammillatum

*Pseudosonneratia

(Isohoplites)

steinmanni

 

 

 

Otohoplites bulliensis

 

 

 

 

Protohoplites (Hemisonneratia) puzosianus

 

Otohoplites raulinianus

 

Cleoniceras floridum

 

 

(ii) Highly glauconitic loam with scattered lumps of blackish phosphate and a few spherical nodules at the base

0.275

11.  "Sulphur Band".  An indurated layer of phosphatic nodules, the nodules veined and encrusted with pyrites and embedded in a matrix of clayey greensand, the whole coloured yellow and reddish-brown by decomposition products.  Two distinct concentrations of nodules recognisable.  Abundant fossil wood.

0.38

10.  Course grey sand, somewhat clayey at top

0.45 to 0.61

9. Main mammillatum Bed.  Seam of coarse yellow-green sand and grit with clusters of phosphatic nodules

0.15 to 0.30

9. Very coarse yellowish sand and grit

0.30 to 0.46

 

 

References:

a. Owen H.G. 1971. Middle Albian Stratigraphy in the Anglo-Paris Basin Bulletin of the British Museum (Natural History) Geology, Supplement 8

b. Casey R. 1961. The Stratigraphical Palaeontology of the Lower Greensand; Paleontology, Vol 3, Part 4, pp. 487-621