Sunday, October 29, 2017

The Geology Of India In 220 Tweets

Ok, I am exaggerating.

Last week I hosted the @Geoscitweeps account and tweeted 8 stories about Indian geology. This is an earth sciences focused rotating twitter account curated by science writer Sandhya Ramesh (@sandygrains).  Geologists from all over the world have been volunteering to host the account for a week and tweet about their work. I volunteered for the week beginning October 16 and decided to broadcast some interesting stories about Indian geology.  I had written blog posts about some of the topics, but it still was a challenge to create an engaging  narrative using 20-30 tweets.

Here are the threads:

1) Does India have Cambrian age Burgess Shale type fossils?

2) The Tempo of Deccan Volcanic Eruptions

3) Deccan Lava Flows and Buddhist Caves and Rock Art

4) Piggy Back Basins and Seismic Risk of Himalaya Frontal Ranges

5) Exploring India's Fossil Sites and Paleogeography using the Paleobiology Navigator

6) Which of these Indian Island Chains is Geologically Older? Lakshadweep or Andamans?

7) Evolution of the Western Ghat Escarpment and Coastal Plain.

8) How To Discover Your Inner Geologist When You Go Trekking In The Himalaya

It was really gratifying to see the enthusiastic response by readers from all over the world... and particularly satisfying to see that a large number of Indians began following @Geoscitweeps as news spread that there was Indian geology on the menu.

More Indian geologists need to start writing and talking with the general public about their work. There is certainly an audience out there eager to hear from them. 

Tuesday, October 10, 2017

#Neatrock Entry For Earth Science Week

SciFri Science Club is hosting a #Neatrock challenge as part of Earth Science Week.

Here are my two entries:

Megascopic #neatrock:


This is a migmatitic gneiss from the Greater Himalayan Sequence, Darma Valley, Kumaon Himalaya. Migmatite means a mixed rock made up of a metamorphic host and a newly formed igneous rock. During continental collision, metamorphic rocks buried to great depths and subject to high temperatures may partially melt to form granite magma. The granitic melt segregates into layers. The resultant rock is composed of the original metamorphic host rock such as a gneiss (dark bands)  and granitic igneous layers (lighter bands). This migmatite formed during the Miocene.

Microscopic #neatrock:


This photomicrograph of a Late Ordovician limestone (Fernvale Limestone) from Georgia, U.S.A.  is close to my heart. It formed an important part of my PhD work.  I have stained the thin section with a Potassium Ferricyanide dye. Calcite containing minor amounts of iron (Ferroan calcite Fe+2) is stained blue. Non Ferroan calcite is unstained.  In the center of the photomicrograph is a non ferroan 'dog tooth' spar. It is a calcite crystal with a shape resembling a canine tooth of a dog.

This calcite has a pendant habit. It is hanging from the underside of a particle, in this case a piece of an echinoid shell. Such pendant crystals precipitate in a vadose zone i.e. above the water table.  In this environment, pore spaces are not completely filled with water. Rather, films of water coat grains and form drips. These drips become saturated with calcium carbonate and calcite precipitates from them.  Just like a larger and more familiar stalactite in a cave! Except that this micro-stalactite in tiny..tiny.

Development of a vadose environment indicates that sedimentation was interrupted by a large sea level fall. The sea bed got exposed to rain and a fresh water aquifer developed in the sedimentary deposits.  A tiny 'dog tooth' spar can tell us a fair bit about sedimentary basin evolution and sea level history.

Wednesday, October 4, 2017

Geo Week 2017, Pune

 Geo-Week 2017 Pune

Starting October 9th 2017, a week long geo-activity program for the public is going to be held at Raja Ravi Varma Art Gallery, Ghole Road, Pune.

It is being organized by the Center For Education and Research in Geosciences (CERG) along with Fergusson College, Pune. CERG is a citizen outreach initiative taken by students and professionals from the Pune geology community.

Take a look at the poster.


The inaugural talk by Dr. R. Shankar of Mangalore University will be on October 9th at 11.30 am . The topic is Paleoclimate Studies of Lake Sediments from South India. The venue is Raja Ravi Varma Art Gallery.

There is another lecture scheduled on October 14th  at 7.40 pm by Dr. S. N. Rajguru. The topic is Prehistoric Environment of the Mula Mutha River, Pune. This talk will be held at the Amphitheater on Fergusson College campus.

There is also a geology exhibition, art and essay competitions for school children, earth science themed film shows and a workshop on QGIS. The exhibition is at Raja Ravi Varma Art Gallery, while most of the films will be screened at the Amphitheater, Fergusson College. Check the website for schedule details.

Pune geology and science enthusiasts, share this with your friends and do stop by and support this initiative!

Geo-Week 2017, Pune