In his brief but illuminating commentary on the Psalms, Derek Kidner graphs the relationship between Genesis 1 and Psalm 104.  I have reproduced an expanded version of his exegetical chart below.  It shows well how the Psalmist wrote his hymn of praise in the light of Moses creation account.

Creation Day				Formed & Filled
Day 1	Gen 1:3-5	Light & Darkness	Ps 104:1-2a	Light
Day 2	Gen 1:6-8	Heaven & Earth	Ps 104:2b-4	Divides the waters
Day 3	Gen 1:9-10	Land & Sea	Ps 104:5-9	Land and water distinct
“   “	Gen 1:11-13		Ps 104:14-18	Vegetation, trees, hills/rocks
Day 4	Gen 1:14-19	Vegetation	Ps 104:19-23	Luminaries as timekeepers
Day 5	Gen 1:20-23	Sea & Sky Animals	Ps 104:25-26	Creatures of sea and air
Day 6	Gen 1:24-28	Animals & People	Ps 104:21-24	Animals and Man
“    “	Gen 1:29-31		Ps 104:27-30	Food appointed for all

Derek Kidner, Psalms 73-150, Tyndale Old Testament Commentary (Downers Grove, IL: InterVarsity, 1973), 368.

Of course, the relationship is not hard and fast, many aspects of the Psalm bleed into other sections, but like creation itself there is order and overlap.  Pericopes, like ecosystems, often do not have fixed boundaries, but rather discernible patterns and parameters.  God has called us to find order in his organic world/Word, but not to force our mold on either. For a lengthier description of Psalm 104, read my last post, “Seeing the Glory of God in Creation”

Soli Deo Gloria, dss