Geobulletin alpha

Geological Contacts: Angular Unconformity Kaladgi Basin 

Through the Proterozoic Eon, beginning around 2 billion years ago,  extensional forces acting on continental crust opened up several sedimentary basins across what is now peninsular India. Crustal blocks subsided along faults and these depressions filled in with sediments deposited in fluvial and shallow marine environments. These basins were long lived, some lasting for more than a

The Making Of Iceland 

Committees are underappreciated. xkcd comics.Happy New Year

Geological Contact: Sirohi Fold Belt And Erinpura Granite 

One of  my favorite courses during graduate work in Pune was geological Remote Sensing. We focused a lot on visual interpretation of aerial photographs and satellite imagery. Lab work meant hours of poring over different areas of India and making preliminary geology maps based on observations of the landforms and rock structures visible from space. The rock composition, structure,

I visited the Iceland eruption last summer! 

Dear friends, It’s been a while since I posted any geology. I saw some really cool stuff in Europe during my 5-week trip in July and August. I primarily visited Iceland, northern Italy, and London with a couple nights each in Munich and Innsbruck. I will share the two significant geologic highlights. The first was

Rivers might not need plants to meander 

Here’s a new study that, if true, this would have some big implications for the nature of the sedimentary record for a lot of Earth History. Research from 1.2 billion year-old sediments in Scotland adds the oldest evidence yet against … Continue reading →

Pavement Geology: Ophicarbonate 

You must have come across polished slabs of this dark green rock with white veins, used on stairways and as wall panels. It is an ophicarbonate.The term encapsulates a range of geological processes, often separated by tens of millions of years. Oceanic lithosphere that is being generated by magmatism at mid ocean ridges, where plates diverge, is made up of igneous rocks arranged in a

Exploring The Panchachuli Glacier Geotrail This May 

Folks, join me for a walk to explore the geological landscapes near Panchachuli Glacier, Darma Valley, Kumaon Himalaya. The plan is from May 7 to May 13 2023. This geo excursion is being organized by Deep Dive India. I will be the geology expert accompanying the group. We will be observing a variety of geologic terrains made up of rocks that tell a story of Himalaya mountain building. High

Tethyan Himalaya And Trans Himalaya 

What is the difference between Tethyan Himalaya and Trans Himalaya?I've seen the two terms being used interchangeably, but geologists recognize them as geologically distinct terrains. Their geographic locations and geologic context has been annotated in the satellite imagery below. The Indus Suture is the zone of collision between the Indian and Asian tectonic plates. It contains broken pieces

A Geological Map Of The Himachal Himalaya 

Digging through my collection of Himalaya geology papers, I came across this geological map of the Himachal Himalaya. It is from a study on the tectonic history of the Himachal mountains by A. Alexander G. Webb and colleagues, published in Geosphere in the year 2011. The paper itself is quite a detailed work using both field mapping and various geochemical and geochronologic methods. It will

Obsessing over the Anthropocene’s “golden spike” misses the point of the Anthropocene 

This is a good write-up of the latest step in the long and somewhat contentious process of making the Anthropocene “official”: In the same week as the world’s population ticked over to 8 billion people, the Anthropocene Working Group (AWG) began … Continue reading →

Milam Glacier Trail - Geology 

Geology enthusiasts will find the Milam Glacier trail captivating. The river Goriganga emerges from the glacier and flows in the Johar valley in this region. I walked the trail in Mid October, and came across a variety of geological features of interest. The trail begins in the village of Lilam, just north of the town of Munsiyari in the Kumaon region of Uttarakhand. It passes through the

Juno reveals Europa’s evolving surface 

About a month ago, NASA’s Juno probe buzzed the Jovian moon Jupiter, and we got this cool picture, taken from a distance of about 400 km away. The grooves and ridges criss-crossing Europa’s icy shell are thought to record water from … Continue reading →

The beautiful geological info-art of John Emslie 

Look at this beautiful 19th century infographic, courtesy of the History of Geology on Twitter: Here it is in all it’s glory: Except for the somewhat interesting landscape associated with label 12 – “Earthquakes and elevations of the land by … Continue reading →

Mount Pilchuck geology guide is published. 

I hiked the Mount Pilchuck trail a week ago and just published a field guide on the Northwest Geology Field Trip website and you’ll find it here. I was motivated by an email from long-time reader Wendy B. She hiked Pilchuck last fall and asked me about this ‘standing stone’ near the summit. So I

Just published: can sandbox models be educational and fun? 

Just out: a paper by me and education expert Bridget Mulvey grapples with the question: analogue sandbox models are cool, but are they effective teaching tools? Analogue sandbox models are a way of demonstrating tectonic deformation processes in the classroom: the … Continue reading →

Not enough people get taught Earth Science, and that’s a problem for all of us 

This article articulates an increasingly concerning question: in a world where increased exposure to natural hazards, resource scarcity and the consequences of climate change are amongst the most critical issues facing our society, why does Earth Science get no love in … Continue reading →

Weird rocky exoplanets 

Obtaining the composition of rocky exoplanets from the spectral signature produced when their dying parent star eats them is already pretty mind-blowing. But the results – which suggest that on some of these worlds, quartz is substituted for olivine in their … Continue reading →

Diversity (or lack thereof) in geoscience: are we hyping up the wrong things? 

Via Dr Sarah Greene, some data from a survey of student attitudes to STEM careers, including geosciences, at a college in the SW US indicates that they care more about whether their career can help people or the environment than the … Continue reading →

Geology Crossword 

A couple of years ago I reconnected with my Florida State University friend Shanker Venkateswaran.Shanker is quite a geology and nature enthusiast. He has put together this geology crossword for beginners on the Crossword Club website.Click on the link below for the full set of clues and the interactive version.Geology Crossword -

Be a geoscience and data science detective 

Introduction These days everyone talks about data science. But here’s a question: if you are a geoscientist, and like me you have some interest in data science (that is, doing