Thursday, April 25, 2013

My Criticism Of K.S Valdiya's Paper Published In Current Science

and Valdiya's reply was not satisfactory at all..

To those unfamiliar with the sequence of events:

1) Giosan et al publish a paper in the May 2012 issue of PNAS on fluvial geomorphology of rivers around the Harappan civilization and conclude amongst other things that the Sutlej and Yamuna rivers got diverted from the channels now occupied by the river Ghaggar (Haryana Punjab plains) to their present day course by Late Pleistocene. This meant that the Harappan civilization along the river named Ghaggar -also identified as the Vedic Saraswati by many- was watered by a monsoonal river and not a glacially connected river.,

2) I write a blog post of this paper on June 15 2012. I comment that some Indian geologists working on this problem accepted the scenario of a glacial Ghaggar /Saraswati during Harappan times without critically assessing the evidence.

3) My blog post appears on the Indo-Archaeology forum.  In the confusion due to many cross links my comments about the role of Indian geologists are misattributed to Giosan et al.  Giosan tries to set the record straight. K.S. Valdiya based on his correspondence with S. Kalyanaraman also confuses the source of those comments and misattributes them to Giosan et al in his article in Current Science. Valdiya accuses Giosan et al of diminishing the research of  Indian geologists partly because he misidentifies Giosan et al as the authors of those comments and partly because of Giosan's comment on the Indo Archaeology forum  that they have only referred to 'papers and authors presenting reliable data and facts’. S. Kalyanaraman forwarded this comment to Valdiya who then regarded it as a slight on the work of Indian geologists.
These below are my words that got misattributed to Giosan et al:

A geological narrative constructed without rigorous evidence has been promoted to support a theory of cultural evolution in northwest India.


..  now be revised or at the very least these geologists  need to admit that their theory has been seriously challenged.

4) I write a blog post on the geological problems in Valdiya's Current Science article.

5) Giosan et al protest the misattribution in the Correspondence section of February 10 issue of Current Science.

6) My comments and Valdiya's reply to Giosan et al and my comment published in the April 25 issue of  Current Science.

phew... I didn't know writing a nerdy geology blog will land me in such a controversy! :)

Moving on to Valdiya's reply to my comment I want to elaborate on Valdiya's denial that he misrepresented the work of other authors.

1) Valdiya commenting upon Saini et al writes:

Kher accuses me of misinterpreting the deduction of Saini et al. [..], who clearly state that the sedimentary succession of the area between Tohana and Sirsa which is ‘considered as a part of the area’ through which the ‘lost’ Saraswati flowed (p. 1634), contains grey sandyfacies with ‘grey sediments similar to the modern day sediments of the mountainfed rivers’, ‘like Ganga and Yamuna’ (p. 1637) and ‘The mineralogical characters, extent and style of the grey micaceous sand suggests that it was a Himalayan mountain-fed multi-channel fluvial system.’ Taking in conjunction with the findings of Courty [..], I concluded that this fluvial system belonged to the Saraswati. Logical deduction cannot be construed as misrepresentation’.

The devil is in the details. Saini et al discover two phases of fluvial activity in the Haryana plains. They find that fluvial activity weakened from the Pleistocene to the mid late Holocene. The sentences that Valdiya refers to are descriptions of a large fluvial system - termed F-1- active in the Pleistocene, before the Last Glacial Maximum about 25,000 to 30,000 years ago. Saini et al discover another much younger phase of fluvial activity (F-2) active between 6000 B.P and 2900 B.P (Before Present) covering a much smaller extent than the buried older Pleistocene system. This younger activity corresponds in age to the Harappan civilization and its sediments are mostly mud and silt, with less of the grey sand present. Of relevance to the problem of the glacial Saraswati is not the older fluvial phase but whether the younger fluvial system overlapping the Harappan civilization was glacially fed or not. Valdiya is his reply doesn't make this distinction.

On the question of the provenance of the younger system Saini et al draw no conclusions.

They say:

The F-2 phase, part of a relict landform, considered as a part of the ‘lost’ Saraswati drainage by previous workers [..] in this part of Haryana matches with the time span of the ‘Vedic’ Saraswati. However, the upstream and downstream connectivity of this segment to the postulated Saraswati course remains elusive and needs further exploration.

Validya on the other hand referring to this younger fluvial activity comments in his paper

Which river deposited these younger sediments in the Hakra reach of the Ghagghar–Hakra river? We believe that it was the Saraswati River originating in the Himalaya.

I have several problems with the way Valdiya has represented Saini et al. In his reply he has cherry picked sentences from Saini et al about the existence of a large multi-channel Himalayan fed -which could be interpreted as a glacial fed-  river network without explaining that this described system was active in the Pleistocene and not during the Harappan civilization.  Moreover, he never clarifies in his original paper that Saini et al don't draw any conclusions about the provenance of the younger fluvial system. He wrongly says in his reply that Saini et al allude to the river coming from the Siwaliks. That remark is not from Saini et al but from Saini and Mujtaba who suggest that river active during Harappan times was fed only from the Siwaliks.  To that, Valdiya's reply is that the Siwaliks are the Outer Himalayas (the southernmost range) and he has always stated that the Himalaya-born Saraswati flowed through the Siwalik terrain! He misses the point that Saini and Mujtaba's work indicates that the river could not have been glacially fed during Harappan times

Finally, he is not a co-author on Saini et al. Despite that he uses the word "We" which might confuse readers into thinking that Saini et al are going along with Valdiya's conclusions. Presumably the "We" doesn't include Saini et al but stands for the collection of geologists who support the theory of a glacial Saraswati as Saini et al decidedly do not come to the same conclusions as Valdiya regarding this younger fluvial phase.

2) On the issue of misquotation of Giosan et al, Valdiya writes in his reply:

I have correctly interpreted what Giosan et al.1 have written in their article. The only error I committed was the wrong placement of quotation mark. I am sorry for this inadvertent mistake. But
the meaning conveyed is the same as what Giosan et al.1 intended.

Let me place next to each other the original passage from Giosan et al and Valdiya's reproduction:

This is from Giosan et al:

‘Provenance detection (...) suggests that the Yamuna may have contributed sediment to this region during the last glacial period, but switched to the Ganges basin before Harappan times. The present Ghaggar– Hakra valley and its tributary rivers are currently dry or have seasonal flows. Yet rivers were undoubtedly active in this region during the Urban Harappan Phase. We recovered sandy fluvial deposits approximately 5,400 years-old at Fort Abbas in Pakistan (SI Text)…’.

And Valdiya's reproduction:

‘Interestingly, Giosan et al. (...) concede that... “the Yamuna may have contributed sediment to this region…” (Hakra– Ghagghar) “before the Mature Harappan Phase. For we recovered 5400-year-old
sandy flood deposit at Fort Abbas (in Cholistan) Pakistan”…’.

Valdiya is now saying in his reply that his only mistake is wrong placement of quotation marks. Which means the phrase "before the Mature Harappan Phase" and the word "For" should have been outside quotation marks and they really are Valdiya's words and not Giosan et al. But does he not realize that adding this text along with his phrase "Interestingly, Giosan et al. (...) concede that" changes the meaning of the original passage?  Giosan et al conclude based on Clift et al's provenance work that the Yamuna was diverted from this area and was captured by the Ganges basin in the Pleistocene perhaps as early as 50,000 years ago.

Phrases like Giosan et al concede- before Mature Harappan Phase- For make it appear that Giosan et al's work indicate that the Yamuna was flowing in this region around 5400 years ago i.e. during early Harappan times. That is certainly not the meaning Giosan et al intend. And in their respective papers these two passages end with very different conclusions. According to Giosan et al,  a monsoonal river was flowing through this region all through Holocene.  In contrast, Valdiya has been arguing all along that glacial rivers were flowing in this region until late Harappan times i.e. around 4000 B.P or so.

Giosan et al will be writing about the scientific issues Valdiya has raised in an upcoming issue of PNAS. I do hope Valdiya sends in his critique too.

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