the supai group members were created from marine (oceanic) sequences of marine transgression, and regression, thus the alternating sandstone, siltsones, conglomerate subsections (facies); the subsections are not always a continuous transition into the above section, mostly due to ocean levels, falling, or rising, glaciation, or regional subsidence-(basins, etc.) or uplift of land. today's wasatch front is the approximate lineage, nne to ssw of the western coast region of north america from where the oceans transgressed. the ancient antler mountains-(antler orogeny, off-shore volcanic island arch(es)), of ancient nevada supplied material, from the west, off the 'ancestral' west coast. the continent supplied material from the east, both directions supplying the offshore basin, the cordilleran basin which became part of the basin and range province, in later epochs. three other basins were involved in this history: southwest of the ancestral rocky mountains was the paradox basin-(eastern utah to southwest colorado), northeast was the central colorado basin-(nw colorado, ne utah, sw wyoming); the oquirrh basin was north-northwest, at present day northwest utah.