For an unholy usage; they raked up,
And shivering scraped with their cold skeleton hands
The feeble ashes, and their feeble breath
Blew for a little life, and made a flame
Which was a mockery; then they lifted up
Their eyes as it grew lighter, and beheld
Each other's aspects—saw, and shrieked, and died—
Even of their mutual hideousness they died,
Unknowing who he was upon whose brow
Famine had written Fiend. The World was void,
The populous and the powerful was a lump,
Seasonless, herbless, treeless, manless, lifeless—
A lump of death—a chaos of hard clay.
The rivers, lakes, and ocean all stood still,
And nothing stirred within their silent depths;
Ships sailorless lay rotting on the sea,
And their masts fell down piecemeal: as they dropped
They slept on the abyss without a surge—
The waves were dead; the tides were in their grave,
Earth has become the epitome of death. There is no more life, or sound, or warmth. Only darkness remains. Darkness and silence. 
 This worth a comparison to Genesis 1:2  “and darkness [was] upon the face of the deep” , however,  no “Spirit of God moved upon the face of the waters” in Byron’s vision. The world is abandoned without God or hope of salvation. 
 Where is the source of this cancerous darkness? The deprivation of light has caused the earth to decay into a caracas.  Once harboring life with light; now a sailor-less sea.  Clay is not living and is representative of a primordial essence.  Nietzsche refers to an unchiseled block of clay as an aphorism for the untainted Dionysian realm, which has not been formed (or defiled) by the Apollonian light from the sun. 
 The “hard clay” could also be a reference to Genesis, in which Adam is made from clay. Instead, in Byron’s vision, the clay is not malleable, capable of being formed into creation, it is “hard” and “chaos” (an antithesis of artistic creation). The Biblical clay that created human life is but a “lump of death”.
Darkness