CIPW Classification and Ratios

The video tutorial covers the practical aspects of petrology, focusing on the CIPW classification system. It explains how to convert molecular proportions into percentages and details the classification into classes, orders, ranges, and sub-ranges. The tutorial provides a step-by-step guide on how to fill out the classification table and includes an example to illustrate the process. Key concepts such as salic and femic ratios, and the importance of accurate calculations are emphasized throughout.

What is the first step in the CIPW classification process?

• Naming the rock

• Converting molecular proportions to percentages

• Filling out the form

• Cross-checking calculations

How do you cross-check your calculations in the CIPW classification?

• By ensuring the total is near 100

• By comparing with a standard table

• By using a calculator

• By asking the teacher

What is the classification based on the salic biofemic ratio called?

• Sub-range

• Range

• Order

• Class

If the salic biofemic ratio is more than 7, which class does it belong to?

• Salic

• Peralkalic

• Dosalic

• Persalic

What is the ratio used to classify the order in the first three classes?

• Q by F or F by L

• P by O

• MGO by FeO

• K2O by Na2O

What is the term for the predominance of alkali in the first range?

• Alkali Calci

• Pericalcic

• Peralkalic

• Domealkalic

How many sub-ranges are there in the first three ranges?

• Three

• Five

• Nine

• Seven

What is the basis for the section division in classes four and five?

• Q by F ratio

• MGO by FeO ratio

• K2O by Na2O ratio

• P by O ratio

In the practical example, what is the salic value used?

• 35.37

• 93.93

• 58.56

• 24.4

According to the practical example, what is the final classification of the rock?

• I1 3

• I2 1

• I3 2

• I3 1