Joseph G. Medlicott

Joseph G. Medlicott (died 1866) was a geologist and General Assistant with the Geological Survey of Ireland.[1] He studied the geology of India.

Background

J. G. Medlicott had graduated from Trinity College, Dublin. In the year 1851, he relinquished his post and joined the Geological Survey of India which was established by the East India Company and the Government of Bengal. While in the GSI, he got engaged in a mapping program to find coal deposits started by Thomas Oldham, who was the first Superintendent of the Geological Survey of India. Soon after, Joseph's younger brother, Henry Benedict Medlicott also left for India and after serving as Professor of Geology at Roorkee, joined the Geological Survey of India. It was H. B. Medlicott who first coined the term Gondwana in 1872 for the coal bearing formations of India.

Narmada-Son line

That the Narmada and Son Rivers flow in a straight line of disturbance from the Gulf of Cambay in the west to the Ganges valley in the east and that this line marks not only the southern boundary of the late Proterozoic Vindhyan Supergroup rocks but also the northern limit of deposition of the coal-bearing Gondwana rocks was first shown by Joseph G. Medlicott, a member of the founding team of the Geological Survey of India, as early as in 1860.

It will not be an exaggeration at all to say that this entire memoir is nothing but an account of the Narmada-Son line, and its principal thesis is the focus on the aspects of the line of Narmada and Son valleys, albeit with a rather primitive geological or scientific knowledge base as could be expected of a mid-nineteenth century publication. Geologists in India do not know this too well since the memoir in question is out-of-print but those working on the aspects of Narmada Son line must not fail to acknowledge this epoch making great work by an unmatched genius and the concerned scientist engaged in research on Narmada-Son line must cite it in the list of references at the end of the paper.

In central India, there occurs an important tectonic lineament, viz. the Narmada-Son line stretching from Broach near the Gulf of Cambay, where Narmada River meets the Arabian Sea, to as far east as the place called Dehri-on-Son where Son River drains into the Ganges. The characteristic feature of this lineament, along which two major rivers flow is that it marks the southern limit of deposition of the sediments (and sporadically occurring volcanics) of the rocks of the Vindhyan Supergroup; besides, it also forms the northern limit of the coal-bearing Gondwana Supergroup rocks. The existence of this peculiar and tectonically significant feature was first very elaborately described a good one hundred and fifty years ago by Medlicott in a memoir titled The Geological Structure of the Central Portion of the Nerbudda District. In fact the entire memoir is devoted only to this aspect of this important tectonic feature. In 1962, a hundred years after Medlicott's work was published, this work was plagiarised by William Dixon West, then a Professor of Geology in the Department of Applied Geology, Dr H S Gour University, Sagar, India.

Medlicott mentioned two important points about this unique feature of tectonic significance in Central India and he focuses repeatedly on these two aspects throughout the course of discussion in this memoir. These two aspects are:

(i) This feature of Vindhyan escarpment and the valleys of the Narmada and the Son rivers being extremely straight or rectilinear for an appreciable distance; and

(ii) That the rocks of the Vindhyan Series occur only to the north of the two valleys and are not found anywhere to the south of these valleys and the rocks containing coal were to be found only to the south of this linear feature and not to the north of it in the vast stretch of area that was covered.

Regarding the first of these points of great significance, Medlicott remarked (1860, p. 228): “This line of escarpment joins the north side of the valleys of the Nerbudda and of the Sone; it deviates little from a straight line, when considered as a whole, and even within shorter limits, its rectilinear direction is very remarkable.”

On the second point of significance, Medlicott has had a lot to say. He has emphasised this second point at numerous places in the text of this 340 page memoir, of which nearly 200 pages are occupied by the paper by Medlicott. Also, the name Vindhyan was coined by the Geological Survey of India during this period only. Medlicott remarks (1860, p. 115): "The entire group of Sandstones, Shales, &c., of Bundelcund and Rewah which lie north of the River Nerbudda, (or more correctly of that part of the river Nerbudda included in our map,) the great scarp of which rocks is well seen along that valley as that of the Sone, was separated totally from the Sandstone rocks associated with coal, &c., which occur to the south of those rivers, and with which it had previously been confounded: to this great group the name of the Vindhyan was applied, as being best seen in the Vindhyan range”.

He then points out to say that the rocks of the Vindhyan Series are different and were therefore separated from those such as Talchir Series, Mahadeva Series etc. For example, (Medlicott, 1860, p. 119):” Thus the Table land of Malwah and Bundelcund is formed of the sandstones seen in the Vindhyan escarpment, and described in the following pages under the name of “Vindhyan Sandstones”, a group of rocks not known to occur anywhere south of this line of the north escarpment of the Nerbudda valley, at least not within the area mapped. In a similar manner the line of escarpment bounding the valley on the south, marks the northern limit of a series of rocks, which will be found described below, as including those formations called in our lists “Talcheer”, “Damuda”, “Mahadeva” &c., and no rocks belonging to any of these groups are known, within our area, to occur north of this line of escarpment”.

About the general extent of Narmada Son line and the disposition of rocks of two different types occurring to the north and the south, Medlicott said (1860, p. 228), “The remarkable physical features now to be fully described, characterize with more or less distinctness, the band of country stretching from the Gulf of Cambay on the west, to the Ganges valley on the east, and including the Sone as well as the Nerbudda River. Most maps of British India show a marked range, called the Vindhyan Range, running along this line; Mandu stands near the western extremity of it, as generally shewn on the published maps and Rotasgur at the eastern end. Running parallel to this line, is a much less regular range, very different in general aspect, formed as has been stated, of other rocks, and lying on the south side of the Nerbudda valley, within our area. Beyond the district surveyed, a very similar arrangement is known to form a continuation of the range along the banks of the Sone, the south side of whose valley has been found, (in part of its course at least) to be formed, like that of the Nerbudda, of rocks different from those of the Vindhyan escarpment".

Again on p. 146 of the memoir he emphasises the distribution of the Vindhyans and the Gondwanas as being on two sides of this major conspicuous lineament. Quoting him (1860, p. 146)," If we take together the sub-divisions §5, §6 and §7 (Talchir, Damuda and Mahadeva) of our list, it will be seen from the map that rocks belonging to these groups, form the ranges which bound the Nerbudda valley on the south, as the Vindhyans do that which bounds it on the north". And he further goes on to say :"Nowhere have the Vindhyans been seen in contact with these rocks (Gondwanas) and between the boundaries which respectively limit the two groups, a long country lies, which may be considered as occupied by the crystalline rocks, these being however, for the most part, covered by the more recent ossiferous sands, and gravels, and surface clay".

Medlicott also noted that the entire range and the valleys had a singularly uniform trend of ENE-WSW, or more precisely a trend N75ºE-S75ºW. Quoting him (Medlicott, 1860, p. 141), "The rocks of the Vindhyan series cover an immense area in Central India (see map Pl. III). The great Table land of Bundelcund and Malwah is mainly formed of them, and their southern boundary, continuous as it is with that of the table land itself, is marked, as has been stated, by one of the finest physical features imaginable: the vast plateau terminates on the south in a line of escarpment which, stretching from east to west(or more correctly E 15ºN), (that is N 75ºE)forms the north side of the Nerbudda valley, and farther on towards the east holds a similar position in that of the Sone river”.

The Vindhyans are known to have a monotonous composition over extremely large areas and lateral sedimentological variations are but few. This fact was also noted by Medlicott and that despite this there are variations at some places. Quoting him (1860, p. 142):” ….its most marked characteristic certainly is the persistency of this lithological aspect over great areas. This sameness of texture is strongly in contrast with the prevailing character of all those more recent sandstone formations to the south……” And further, “This general constancy in lithological character does not, of course, imply the entire absence of varieties among the beds of the series : instead of clear quartz grits slightly earthy sandstones are found, and in many places ferruginous clay has been so strongly accumulated as to form a considerable ingredient in the mass.” Regarding the subhorizontality of the Vindhyans, Medlicott remarked (1860, p. 141),” …that a slight undulating dip is the rule, so slight as to leave most commonly an impression of general horizontality, in spite of great disturbances which have locally affected the rocks along their southern boundary.”

Soon after the publication of the memoir in question, Medlicott appears to have retired from the Survey or relinquished his position, because the literature shows that he was assigned a job to compile a report on the cotton plantation (Medlicott, 1862) in Bengal Province assigned to him by Lord Canning. For this he was rewarded in money and by being made a member of the Senate of the Calcutta University. He was a frequent writer in the Calcutta Review. Darwin wrote out to India to discover the author of an essay on his "Origin of Species" and finding it was Mr. Medlicott he wrote a most flattering letter to him saying that his was the best essay on the book. In 1862 he joined the Education Department of Bengal. The duties of post he occupied were reportedly ably discharged up to the time of his death.

Death and legacy

He was struck with Paralysis in 1863, went home to Dublin but could not stand inactivity and returned to India, where after a short resumption of his duties his health entirely gave way and he finally sank. He died on 10 May 1866. In an article from a newspaper it was mentioned:[2] By the death of Mr. J.G. Medlicott the Government loses one of its few enthusiastic servants, and India one of its few scientific men. Another newspaper article in the Pioneer says: The deceased gentleman was an accomplished scholar and an able writer and his death is a public loss to the literary world of India.

He was survived by his wife Agnes and son Samuel. The latter is reported to have later died in 1900 in British Columbia, Canada. An account of Medlicott after his death was given in the annual report of the Asiatic Society of Bengal in 1867 which mentioned that "Mr. J.G. Medlicott was well-known as one of the earliest and most energetic members of the Geological Survey of India.”

Notes

  1. ↑ Davies, Gordon L. Herriers (1995). North from the Hook: 150 years of the Geological Survey of Ireland. Dublin: Geological Survey of Ireland. p. 42. ISBN 1-899702-00-8.
  2. ↑ "Notes on the Family of Medlicott of Dunmurry". www.medlicott.eu. Retrieved 24 November 2010.

References

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