Figure F7. Simplified conceptual diagrams showing (A) plan view and (B) a fence diagram cross section of the possible relationships between shallow plutons (white, funnel shaped, numbered in order of intrusion), underplated olivine gabbro crystallized from ferrobasalt (gray), and primitive cumulates (black) frozen in columnlike conduits in the vicinity of ODP Hole 735B. Resulting notional series in Hole 735B are on the right. Note that Series 1 (Pluton 5) and some portion of Series 3 (underplated) postdate Series 2 (Pluton 2). Red arrows give hypothetical directions of migration of ferrobasaltic magmas as they are expelled from the funnel-shaped plutons beneath a brittle-ductile transition that deepens with distance away from the center of spreading. That transition shifts toward the center of spreading as spreading proceeds, driving ferrobasaltic liquids to successively greater depths, eventually prying the deeply rooted primitive cumulates in the columns beneath each funnel away from their mantle sources.

Figure F7. Simplified conceptual diagrams showing (A) plan view and (B) a fence diagram cross section of the possible relationships between shallow plutons (white, funnel shaped, numbered in order of intrusion), underplated olivine gabbro crystallized from ferrobasalt (gray), and primitive cumulates (black) frozen in columnlike conduits in the vicinity of ODP Hole 735B. Resulting notional series in Hole 735B are on the right. Note that Series 1 (Pluton 5) and some portion of Series 3 (underplated) postdate Series 2 (Pluton 2). Red arrows give hypothetical directions of migration of ferrobasaltic magmas as they are expelled from the funnel-shaped plutons beneath a brittle-ductile transition that deepens with distance away from the center of spreading. That transition shifts toward the center of spreading as spreading proceeds, driving ferrobasaltic liquids to successively greater depths, eventually prying the deeply rooted primitive cumulates in the columns beneath each funnel away from their mantle sources.