This verse in Amsha 1 Adhyaya 4 of the Vishnu Purana describes the aftermath of Vishnu’s incarnation Varaha rescuing the Earth from the water:
Uttishtatah tasya jalaardra kuksheh mahaa varaahasya maheem vigruhya |
Vidhunvato veda mayama shareeram romaantarasthaa munayah stuvanti ||
Through the indentations made by his hoofs, the waters rushed into the lower worlds with a thundering noise. Before his breath, the pious denizens of Janaloka were scattered[.]
Here is what the 11th century Sri Vaishnava Acharya Engalalwan says about this verse in his commentary on the Vishnu Purana, followed by U. Ve. A. Narasimhan Swami’s summary of the commentary:
Prayaanti ityaadi |
Varaahasya khuraagrena vikshate videerne rasaatale sati, adhah anda kataahe prayaanti sma |
Kruta shabda santati iti kiyaa visheshanam |
Tathaa cha shri vishnu dharmottare gangaa vyaaptou paataalaani adhikruti uktam * roukma bhoumaat adho yaataa roudram tejah sudaarunam |
Tatra api avilayam yaataa varaaham lokamaagataa |
Vaaraaha loke brahmaandam adha oordhve bhinnavaan harih |
Chidrena tena saa devee svaam yonim punaraagataa |
Rasaatala being torn apart, the waters started moving down in the anda kataaha. Great noise was made by the moving waters, when the Rasaatala got torn apart. Sri Engal Aalwaan quotes Vishnu Dharma, where Ganga came from Deva Loka to here, it went to various worlds. Various layers of the earth are told - shveta bhouma, rakta bhouma, shilaa bhouma, rukma bhouma. Crossing all of this, it came to Vaaraaha loka. Brahmaanda was torn apart into two halves by Hari. After that, He again came back to the original place.
I’m interested in the part in bold. My question is, what scriptures describe Shveta Bhouma, Rakta Bhouma, Shila Bhouma, and Rukma Bhouma, the layers of the Earth alluded to by Engalalwan?
Note that I don’t want scientific speculation, I just want to know what scriptures describe these layers.