"WE LIVE AND LEARN!"

Auckland Star, Volume LXXI, Issue 17, 20 January 1940, Page 2 (Supplement)

"WE LIVE AND LEARN!"

5 By - - i A. W. B. Powell

MANY people consider the study of natural history of little use unless it has a definite commercial or utilitarian value. This may appear sound reasoning as far as it goes—the difficulty rests in that it is not possible to decide in advance just what is going to prove of economic importance. The study of some minute and little known insect may suddenly leap into tho limelight as a boon or a bane to horticulture—something smaller still may bo located as a contributing cause io a tropical disease and as the Discover3 r Committee has revealed in its researches into whaling problems the whole structure of whaling rests upon the abundance and well being of several

/ : 5 ; s speeies of shrimp-like creatures which ( in turn are dependent solely upon the t ~ seasonal abundance of tiny diatoms, ( forms of primitive plant life. ; o Equally minute and abundant in the I 0 soa are a primitive group of organisms i e which are tc.rmed foraminifera. * 1 Students of these minute forms of life * e used to be left alone as harmless addicts t - —but not so now. To-day, the fora- * * minifera expert is much in demand, for * 0 his work when applied to geology is of c ' 1 the greatest assistance in the location 11 1 of oil. t t

Foraminifora belong to the protozoa, a group which includes the most primitive animal life. These tiny creatures form shells, often of the most exquisite beauty, and perforated with minute holes or "foramina"—hence their name. More than 2000 living and fossil species are now known to science, and all save 0110 small group are marine. Some are to be found between tide marks, others on the sand or mud, or adhering to seaweeds, while some are what is called pelagic—that is to say they drift about near the surface in tlie open ocean. The tiny shells fall to the bottom by the million and thus through the ages great thicknesses and immense areas of sea bed have been formed. It is now thought that the soft parts of these foraininifera, along with other minute forms of life, are one of the,main sources from which the oil deposits have been formed. Thus tho insignificant and once almost unnoticed foraininifera serves not only in the natural production of petroleum, but their shell-remains, by their abundaneo in nearly all sedimentary rocks, enable the geological specialist to index and correlate the strata of the rocks

with groat precision. Oil becomes imprisoned often far beneath the surface, in the arches as it were—anticlinal folds in ilio geological terminology—and it is the object of the oil geologist to determine where those likely oil reservoirs occur. As many of the foraminifera have a short range in geological time, each stratum has its own distinctive species and so by intensive fora.miniferal research earth contours often deep beneath the surface can-be accurately mapped. Only when this is done and likely spots for oil are determined does the expensive work of boring commence, and then each section of the core brought up by the drill is examined minutely for its fossil foraminifera and so the exact ago classification of the various strata passed through is ascertained as the boring proceeds. It may interest readers to learn that our New Zealand specialist, Dr. H. J. 1' inlay, of the Geological Survey, <S> !

Wellington, is engaged continuously on research into foraininifera with a view to assisting in the location of oil deposits in this country. Already Dr. Finlay has published several papers oil this work and it is evident that apart from benefits to oil interests the work will have a wide value also in providing moro precise age determinations and correlations of our sedimentary rocks. T'lio shells of tho foraminifora are built up in an interesting way, for they begin as a simple sphere, with an open* ing at tho top. As growth proceeds the jellv-liko substance exuding from the mouth of tho shell forms a second and larger chamber. And this process of growth may go on until many such chambers are formed, the mouth of each opening into the floor of the one above it. In some these chambers are ranged in a straight line: in others they giro rise to a spirally-coiled shell. There are yet other species which build a shell by cementing together dozens of tiny sand grains. The tiny perforations in the shells of foraininifera are for th« protrusion of tho delicate filaments of the animal, and these serve in the capture of food. _ '

Even tho Great Pyramids of Egypt aro built of limestone that was formed millions of years ago at the bottom of tho sea through the gradual aocumulfl* t-ion of tho dead shells of millions of foraminifera. These were large species resembling coins, from which resem* blance they gained the name of nummulites. Even to this day there arc large areas of the Egyptian desert where these fossil nummulites lie loose in the sand. Tho nummulitic limestone, as it is termed, extends in a continuous mass from Africa into Europe, sweeping eastwards through the Alps, Carpathians and Can* casus, across Asia to China and Japan; proof of the former extent of a va6t ocean now dry land. To the ancients the loose numnuilitcs of the Egyptian deserts were not fossil marino organisms, but in their opinion they represented the petrified remains of beans left behind by the builders of the Pyramids—"wo live and learn!" <2>