Learn Turkish: Bu mağarada dikitler birkaç katmandan ibaret. - In this cave, the stalagmites are composed of several layers.

The word ibaret means composed of, consisting of, or nothing but. It is a postposition that always requires the noun before it to be in the ablative case (-dan or -den). Therefore, katmandan ibaret is the required grammar structure for composed of a layer.

The English translation says several layers, so why is it birkaç katmandan instead of the plural birkaç katmanlardan?

This is a common rule to remember: in Turkish, nouns that follow plural quantifiers like birkaç (several), az (few), or specific numbers do not take the plural suffix -lar or -ler. The noun remains singular in form, so it is just birkaç katman, which then takes the ablative ending to become birkaç katmandan.

Why doesn't the sentence end with a verb suffix, like ibarettir?

In the third-person present tense, the to be copula is often simply implied by the noun or adjective at the end of the sentence. Adding the suffix -tir to make it ibarettir would make the statement sound a bit more formal, encyclopedic, or definitive, but leaving it as just ibaret is perfectly natural for a standard factual sentence.

What is the root of the word dikitler (stalagmites)?