1.2. Types of Basaltic Lava

This is a kind of lava where we talk about the ‘Aa’ which is the basaltic lava which is characterized by a rough or a rubbly surface and these lava blocks also we actually extract the clinker from this kind of rough and rubbly surface lava is called ‘Aa’.

The 'Aa' lava type is rough and has a broken, rubbly surface. It forms when lava cools quickly and solidifies in a rough texture. This type of lava can be challenging to walk on due to its jagged surface. It's often associated with more explosive volcanic eruptions, where the gas content is higher, leading to cooler and thicker lava flows.

Imagine walking on gravel or shards of glass; that's what walking on 'Aa' lava feels like! Just like how it's hard to find smooth paths on such a surface, moving over 'Aa' lava can be difficult and slow.

This is a very smooth surface which is unbroken lava that has a very smooth, billowy, undulating or a ropy surface and this is called a Pahoehoe and this is a Hawaiian meaning which is called smooth and unbroken lava, it just floats in a very smooth liquid like you know when the mercury starts flowing down.

Pahoehoe lava has a smooth and ropy surface, unlike Aa lava. It flows more easily because it's hotter and less viscous, creating a more fluid motion. As it cools, it can display beautiful, wave-like patterns on its surface. This type of lava typically indicates less violent eruptions since it flows steadily.

Think of pouring thick honey on a surface; it moves gracefully and forms flowing shapes. That's similar to how Pahoehoe lava flows before it cools and solidifies.

When these kind of molten lava gets cooled up that is where it develops the structural forms whether structural joints are developed and some hollow spaces are also developed.

As lava cools and solidifies, it can form various structural features. This includes joints, which are cracks that occur as the lava cools and shrinks. Additionally, spaces may form within cooling lava, leading to cavities or hollow areas where once molten rock flowed.

It's like making a chocolate cake. If the batter is still too hot when it solidifies, it might crack or form air pockets. Similarly, the cooling lava solidifies and can create structures and holes.

Now, what we can see is the layers of the horizontal layers of one over the another. So, these layers also talk about these beds which are talking about, so a set of lava have come down and gradually another set of lava and by the time it cools down the another set came, another set came.

As lava flows continuously from a volcano over time, it creates layers that stack upon one another. Each layer represents a different flow of lava that has cooled and solidified. The accumulation of these layers forms what we call lava beds, and they provide insight into the volcano's eruptive history.

Consider making a layered cake with different colored icing. Each layer of icing represents a different flow of lava. As you add more layers, the cake gets taller, just like how a volcano builds up its layers over time with each eruption.

This Tacheletic Basalt which is not a conducive rock for cave excavation as its chemical properties react sharply with moisture and disintegrate into pieces.

Tacheletic Basalt poses challenges for excavation due to its chemical composition. When exposed to moisture, it can break down and disintegrate easily. This reaction makes it difficult for archaeologists and geologists to excavate safely without losing important geological evidence.

Think about how a wet sponge breaks apart when squeezed too hard; similarly, Tacheletic Basalt becomes fragile when moisture is present, complicating any excavation efforts.

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