ToL. VII. Xo l.-)l 



THE AGRICULTURAL NEW?. 



45 



GEOLOGY AND MINERAL RESOURCES 



OF BARBADOS. 



The j)ort.ions of Dr. Ells' pn per. which relate to tlie 

 Geology and Mineral Re.soiiices of Barbados are here 

 reprocl lined, in coiitinuaiiou of the extracts ihat 

 nppeareil in the List issue of the Ayrlcultaral News 

 (Vol. VII, p. SO), dealing with the i-sland of Trinidad : — ■ 



111 liarbailiis, the geological foiiuatioiis are somewhat 

 diiferent from those of Trinidad. (Jftlie 166 square miles 

 in the area, six-sevenths are occupied by coral limestone, 

 which doubtless at one time formed a complete capping over 

 the whole island. This coral formation reaches ti) the 

 highest points of the island or about 1,100 feet above the 

 sea, though to the ordinary observer or visitor the ishind 

 is usually regarded as of but small elevation. The remaining 

 seventh in the north-eastern portion shows a .series of 

 Tertiary sediments which aie almost identical with those 

 seen in Trinidad, and, like that island, contain petroleum and 

 manjak'in large quantities. They have been exposed by the 

 denudation of the overlying coral, which presents bold 

 escarpments facing to the east, lietwee'n the Tertiary rocks 

 and the coral is a consideialile thieknfos of earths and clay 

 <lej)osit.s, with an aggregate thickness of nearly 300 feet, 

 which, with the overlying coral tormation, are ijuite undis- 

 tui'lied. 



The Tertiary oil-bearing sandstone and shale are more 

 highly disturbed than those of Trinjdad, the anticlines 

 being sharper and the strata in places loverturned for short 

 distances. As in Trinidad, boring for oil has been carried on 

 for some years as well as mining for nianjak, and some 

 fifteen holes liave been sunk, several of which have 

 been carried to depths of over 1,000 feet. In most of 

 these oil has been found in some ipiantity and a jiijjeline 

 and refinery were erected several year's ago, the oil being 

 pumped from the wells to the lieighf of land whence it 

 descended by gravity to the refining works near the city of 

 Bridgetown. In certain cases the location of the borings 

 was unsuitable, the sediments being too greatly disturbed to 

 be largely productive of oil, so that the yield of petroleum in 

 economic quantity has not been satisfactory ; but at other 

 places the conditions are more favoura^ble, the strata being- 

 more regular and less l)roken, while bpneath the coral and 

 clay formations — the latter being known under the name 

 ' Oceanic beds' —the oil-bearing Tertifiry probably occurs 

 throughout the whole extent of the islan<:l. Here also, owiu" 

 to the covering of inii)ervious clay.s, the possibility of finding 

 oil in paying quantity should be more favourable than in 

 those portions where the clay and coral formations have 

 been removed, as in the north-eastern portion. The thickness 

 of the coral formation varies from a few feet only to I'OO 

 feet, and, in some places, possibly lioO feet, and the Tertiary 

 rocks are sometimes seen, owing to the denudation of the 

 -coral, more e.speL'ially in the sunthern and northern portions 

 of the island. The judicious expenditui'c of a certain amount 

 of ca[)ital by boring in this coral-ripped area slionld lie pare- 

 fully considered. 



In the ()ri_-anic or day andcarlliy deposits arc large beds 

 ■of infusorial earth.s, often beautifully white and resembling' 

 the infusorial earth obtained from the beds of lakes in 

 eastern Canada. The microscopic ekamination of the 

 contained foraminifera, however, sliowslhat the forms are of 

 deep sea water types instead of fresh water origin, as is the 

 case with the northern lake deposits. These infusorial earths 

 • should at some time lie of economir importance. 



The manjak deposits of Barbados occur in true fis^nl■e 

 veins as in Trinidad, the fissures undoubtedly being formed 

 during the general period m uiiheaval which att'ected the 

 Tertiary oil-bearing sands.! The origin of this mineral 

 is rleariy seen in the case., ff- the .shaft referred to, where 

 the manjak pas.sed down at |,50 feet into petroleum. The 

 inference is, that this petrolffiim has flowed into the fissures 

 thus formed, either from thj, sides or bottom, from the oil- 

 sands which have been thu^traversed ; the volatile matters 

 have been largely removed ;iy oxidation, and the asphaltic 

 portion has remained as a vein filling. 



TOBACCO GROWING IN CENTRAL AFRICA. 



The cultivation of tobacco is bec-oniing more ami 

 more popular in the British Central Africa Proteccorate. 

 While in IDGG, the area under tobacco was 955 acres, 

 thhs had increased to 2,330 acres in 1907. In the 

 latter year, too, the tobacco exports were valued at 

 £6,,S89, as compared with .£3.317 in 190G. 



The following information on tobacco, furnished by 

 the Blantyre & East Africa Co. Ltd., is given in the 

 Annual Report fl90()-7) on the protectorate: — 



Tobacco is generally grown by planters, but owing to 

 the season, the crop has not been ijuite .so successful as in 

 the previous j-ear. The drought in January came at a very 

 critical time, most of the plants having then only been 

 recently set out or being w&A'j to put (jut from the nurseries, 

 ilany of those in the field die^l, and the drought stopped the 

 planting out operations. The, result was that large numliers 

 of the plants were lost and the full aci-eage could not be 

 planted up. Following the ' dry weather, the continued 

 rain was prejudicial. Some" of the tobacco which was 

 planted eariy could only he harvested at a disadvan- 

 tage, owing to the wet weather, Avhile the younger 

 tobacco was affected by a improbably fungoidal) disease. 

 This showed up in the cured product as black spots 

 and depreciated the value of the tobacco. The propor- 

 tion of first-class tofiacco \\as therefore small, and the 

 in-op(jrtion of good bright yellow leaf was also much less 

 than expected. In spite of alLdrawbacks, however, the total 

 crop will exceed that of the previous year. The unfavourable 

 conditions were much to be regretted, as efforts were bein;' 

 made to grow a leaf snitalile for the home market, ainl^ 

 natnrall)-, it was desired to make as favourable an impression 

 as possible. There is, however, no doubt now, that excellent 

 toliacco suitable for the I^ritish market can be grown in 

 this protectorate. 



iitibrts during the last few seasons have been chieHy 

 directed to the production of Brights (bellow Leaf), and 

 there is no doubt that Blights will pay the planter best as 

 the prices rage from M. to l.v. pei- It,, on the Liverpool 

 market. All e.states, however, have not the class of .soil 

 most suitable for Brights, and on these a fine sun-cured 

 tobacco has been produced. Although the price for dark 

 leaf is lower than for Ihights, the iieavier yield, to some 

 extent, makes up for the lower prices. It is interesting to 

 note that Turkish leaf has been tried in the Protectorate 

 for the tirst time daring the pas-t season, and that the results 

 obtained ]iroinise success for this chss of leaf. Cigar tobacco 

 production has also received attention, and while it is too 

 soon to iironounco a final verdict, the results, so far, are all 

 favmirable. It is hoped to be able to complete the curing 

 of the leaf and subject it to the iinal test this jx'ar, viz. the 

 test of the open contiiu'iital market. 



