Skip navigation

Hunting fossils in Indonesia

2 Posts tagged with the volcanoes tag
0

By Elena Lo Giudice, University of Kiel

 

This is Elena, a PhD student at the University of Kiel, in Germany. I’m an oceanographer so this is my first time on land and I never thought that the life of a geologist could be so exciting.

 

Our adventure started early in the morning trying to communicate with our driver, a very nice, patient and always-smiling guy. After a couple of misunderstandings we arrived at the outcrop and we started the initial investigation of the area. Our curiosity about a missing part of the rock succession drove us at first to the playground of a school, which was built in the middle of the section. Here we were accepted as rockstars - everybody wanted a picture of us - and then we reached the base of the outcrop, a very important point for our work. We were working on the edge of a mining area - there are lots of coal mines here. We will work on mined outcrops higher up in the section later this week but first we need to have health and safety training so we can be safe around the mining roads.

 


Nathan and Elena school.JPG

Nathan and me with students at the local school

 

Our work today consisted of logging the outcrop, for instance defining the different rocks and geological structures present in the strata – from the base to the top - and measuring them. We make this information into a diagram (a log) so that other people on our trip can use them when they want to collect from the section. This way they will know where their fossil or rock samples came from and when we work out the ages and palaeoenvironments of the sections, they can relate that information back to the fossil faunas and floras they have identified and have more information on how they lived.

 

stadium section.jpg

Layers of clay, silt and sandstone at the Stadion Section near Samarinda

 

So, after this amazing day, I came back to the hotel with our driver’s smile impressed in my mind, a lot of pictures with the school guys and, of course, 80m of logged section, what can I ask more for just a single day?

0

Firemountains, source of life

Posted by Lil S Nov 30, 2010

By Frank Wesselingh, Naturalis Museum, Leiden

 

The amazing volcanoes that straddle Java are here for a reason. This is a short essay on how Indoaustralian nutrients enrich day-to-day Indonesian life.

 

The first physical disorders are already occurring within our group: toothache here, bronchitis there and some of the inevitable stomach disorders. However, the team is in good spirits, certainly after an inspiring day of workshop that included some of the basics of writing a blog.

 

So here you have a blog which tries to explain why there are so many volcanoes around us, written by your molluscan palaeontologist Frank.

 

There are really many volcanoes on Java, I think seventeen of them are classified as active. Many of them have the characteristic conical volcano shape that I learnt as a kid volcanoes should look like. Java is located on the southeast tip of the Eurasian continent, the large plate on which the United Kingdom (and Ireland and the rest of mainland EU) is located.

 

Only a few hundred kilometers to the south of Bandung there is the plate that contains India and Australia, the Indoaustralian plate. That plate and the Eurasian plate are converging. In some places the plates collide and huge mountains, the Himalayas are uplifted. In other areas, such as south of Java, the Indoaustralian plate dives under the Eurasian plate, because of the slightly heavier weight of the former.


2volcanosexplained.jpg

 

the process of making a volcano

 

The submerging plate is drawn into the hot mantle and melts: magma begins to form. Because the submergence occurs under an angle, the melting takes place deep under the Eurasian plate. When enough magma is formed it will seek its way upward and will form volcanoes, like those on Java. When you encounter a row of volcanoes, like here, or in southern Alaska or Peru, you can be certain there must be a subducting plate nearby.

 

2javanvolcanos.jpg
Volcanoes on West Java

 

 

A part of the lava and ashes spewed by the Java volcanoes has an Indoaustralian origin! They are rich in nutrients and make very fertile ground. You can see this in the landscape. Crawling up the flanks of the volcanoes are vegetable plots and villages. People live in places they’d better not and as shown by the recent Merapi eruption, the likelihood of casualti increases.


2fertilelands.jpg

the fertile grounds around the volcano