It is said in the Matysa Purana, that Brahma composes Puranas in accordance with the predominant Guna of that particular day of Brahma (Kalpa):
‘There are four categories — the mixed, the sattvik, the rajasik and the tamasik'
In the various Puranas produced in the past by Brahma, deities have been praised corresponding to the dominant qualities of the epoch of production.
In the epochs of tamas the greatness of Agni and Shiva is praised. In the epochs of rajas the greater greatness of Brahma is praised (Matsya. LIII, 68);’ ‘Then in the epochs of sattva the still greater greatness of Hari is praised. Those who reach realization in them attain the highest goal (Matsya. LIII, 67);’ ‘In the mixed epochs the greatness of Sarasvati and manes is praised (Matsya. LIII, 69).’
And Ramanujacharya in his Vedartha Sangraha, or "Summary of the meaning of the Vedas," says:
The idea of the foregoing is this: Brahma is the first individual self (in the realm of samsara). Therefore even in him, some days sattva, some days rajas, and some days tamas preponderate.
Further, it is to be understood, that in case there is a conflict between the Puranas that have been composed by Brahma on the days in which sattva preponderates and the Puranas that have been composed by him on other days, the Puranas composed on the days of sattva are true and the others in conflict with them and composed on other days are untrue. This principle of evaluation has been formulated by Brahma himself, when established in and devoted to sattva.
The author of each of the Puranas, first of all gathered from Brahma himself all the materials that should go into the particular Purana and then transmitted that body of information through his composition. Accordingly it has been stated, ‘I will tell you, as Brahma, told, in reply to the questions put to him by the great sages like Daksa (Vi. Pu. 1:2:8)’. (This is the governing principle of evaluation in connection with the Puranas).
Currently, we are in the Shveta Varaha Kalpa.
Does any scripture say what Guna this kalpa is?