An apparatus for growing a crystalline sheet from a melt includes a cold block assembly. The cold block assembly may include a cold block and a shield surrounding the cold block and being at an elevated temperature with respect to that of the cold block, the shield defining an opening disposed along a surface of the cold block proximate a melt surface that defines a cold area comprising a width along a first direction of the cold block, the cold area operable to provide localized cooling of a region of the melt surface proximate the cold block. The apparatus may further include a crystal puller arranged to draw a crystalline seed in a direction perpendicular to the first direction when the cold block assembly is disposed proximate the melt surface.