The present is the key to the past, that is what Mr. James Hutton, the funding father of modern geological concept said to answer the ancient rocks phenomena. By learning and studying the present days process on how rocks are formed, how magma were erupted to the surface and why the dynamic of earth occured by sending their signals through earthquakes, landslides, and volcano eruptions. How do sands travel from the mountains to the ocean, how do they interact along its travel from gullies, streams, rivers, deltas until rich the ocean. These are what we see in everyday life.
Those acquire the better understanding to reveal what happened on the earth in the past. What are the geologists think if they face the rock outcrops. Are they layerly distributed? Are they chaotic and mix between very fine, fine grain and boulders in the same place? Or, are they formed in differents type of rocks; the rocks formed in the oceans, rocks formed in the river terraces and mix with rocks from beneath of the earth where those only can be formed in very high pressure and temperature?? Hmm… stop for a while for geologist to think, in what environment are they meet together, I mean, how do rocks meet and bounded together. It took time to meet up, it took place to reach and they need some independent agent to make their dream come through ( I mean, to formulate the rocks hahaha, I guess it is called tectonic?). Well, I write to much just to explain how the rocks, mainly, sedimentary process were formed and in what tectonic condition they meet together. Seems like I am crazy as a geologist just to imagine again and again … and here we are..
I took time to discuss with my colleague, I mean senior colleague. He is interested with the volcanism concepts to answer the local geological history in a place where the ocean and continent meet and create a subduction along westcoast of Sumatera, southerncoast of Java, Bali and NTT and continue to the northern part of Sulawesi, Banda and Maluku. Well, I will say that my country is Indonesia. It is how do I describe in geological ways.
So, back to the volcanism concepts. This concepts is relatively against the sedimentary concepts where the volcosedimentary rocks becomes an precious child to be confronted. In this way of thinking, tectonic is the pioner agent to make magma reach out earth surface and after that magma will find its energy to what ways they wanna formed although the tectonic still has an effort to contribute. The visual interpretations of remotely sensed imageries, the geological maps careful readings and lastly the most expensive, in my term, the geochemical and geophysical imaging could reveals the past volcanism process within the area of interest. The first two methods will become my passion due to its availabilty and various rs datasets in free mode. Well, let’s explore our imagination into the past. I wish I have a machine time in my doraemon pockets, but I have two in my mind, my imagination and my geological thinking. Do they enough? Let’s proof it.