4. Indicate the largest deposits of mineral resources.

Analysis of the map:

The map shows geographical features like rivers and cities, along with a legend for 'Conventional Symbols'. However, there are no symbols or annotations on the map indicating mineral resource deposits.

Task 4: Indicate the largest deposits of mineral resources.

To fulfill this task, the map would need to display specific icons or shaded areas representing oil fields, gas fields, coal mines, mineral deposits, etc., along with their labels. Since these are absent, I cannot identify the largest mineral resource deposits from the given image.

Conclusion: I am unable to complete task 4 based solely on the visual information present in the image.