A. J. Jukes Browne — On tlie Upper Greensand, etc. 355 
Firestone of the Wealden area, and tbeir equivalents of Firestone 
and Chertj T Sandstone in the Isle of Wight. The Warminster Green- 
sand has also been generally accepted as another type of the Upper 
Greensand, and of its Claims more will be said hereafter. 
The Chloritic Marl. 
By whom this name was first proposed, and to what bed or beds 
it was first applied, I have been unable to determine with any cer- 
tainty, nor have the several geological friends whom I have consulted 
been able to enlighfien me on the subject. It seems probable indeed 
that in its first application it was nsed rather as a descriptive term 
than as a designation for any particular bed, and simply as a transla- 
tion of the French “ Marne chloritee.” 
Thus the earliest paper which takes cognizance of it is one by Mr. 
God win- Austen on the geology of the south-east of Surrey, 1843. 1 
After describing the Lower Chalk of this district, he says, “This 
portion of the series, taken in a descending Order, slowly acquires 
an admixture of sand and green earth, so as to become first a craie 
chloritee, tili by the further diminution. of the calcareous matter we 
reach the bright green beds of the Upper Greensand with Plicatula 
inflata.” 
This craie chloritee appears to coincide in position with what was 
afterwards called the Chloritic Marl; but a paper written in the 
ensuing year by Prof. Forbes and Capt. L. L. B. Ibbetson, contains the 
first actual mention of the term that I have been able to find, and 
in this a more indefinite location is assigned to it. 2 The authors 
describe the Cretaceous System as seen in the Isle of Wight between 
Sandown and Whiteclifi Bays, and the following passage occurs : “The 
Upper Greensand corresponds nearly to the section at St. Catherine’s 
Down, presenting successively sands and clays, under the name of 
Chloritic Marl, siliceous bands, firestone and freestone, malm and 
rag, the malm in a 3-feet bed, highly fossiliferous, surmounted by 
26 feet of malm and rag passing into Chalk Marl.” 
The whole description is somewhat confused ; but if any particular 
beds are meant to be indicated by the name of “ Chloritic Marl,” 
they would appear to be sandy marls and clays overlying the Gault - 
clay, and forming the passage-beds to which I have previously alluded. 
The authors may, however, have been mistaken in their identifica- 
tion of the horizon, or they may have merely meant the term to be 
descriptive of the lithological character of the beds. 
However this may be, the term Chloritic Marl had apparently 
been associated with strata at the top of the Greensand or base of 
the Chalk Marl before the year 1848, and by this time the authors 
above mentioned had arrived at more definite views regarding it. 
Captain Ibbetson read another paper before the British Association 
in this year “ On the position of the Chloritic Marl or Phosphate of 
Lime-bed in the Isle of Wight,” 3 the substance of which was in- 
1 Proe. Geol. Soc. vol. iv. p. 169. 
2 Brit. Assoc. Eep. Trans. Sec. 144. 
3 Brit. Assoc. Eep. 1S4 j, iraLS. Sec. p. 69. 
