Universal Product Code. The Universal Product Code (UPC) is a barcode symbology that is widely used in the United States, Canada, United Kingdom, Australia, New Zealand, in Europe and other countries for tracking trade items in stores. UPC (technically refers to UPC-A) consists of 12 numeric digits, that are uniquely assigned to each trade item. Along with the related EAN barcode, the UPC is the barcode mainly used for scanning of trade items at the point of sale, per GS1 specifications.
A-C. Abyssal Plain The flat area of the ocean basins between oceanic ridges and trenches or passive margins. Average depth of the abyssal plain is 4km below sea level. Typically the sedimentary rocks forming here are black shales and turbidites.Accretionary Wedge (prism) A zone of deformed sediment made up of thrust slices scraped off a subducting oceanic plate and added onto the over-riding plate.ontinental Crust A collective term for the crust that forming the continents; it has an average thickness of 35 km but can be up to 70 km under mountain ranges. Typically the composition is granitic with a density of 2.7 meaning that it is too buoyant to be subducted at convergent (destructive) plate margins.
The places where the destruction takes place are called convergent plate boundaries, or subduction zones. Convergent margins are the boundaries formed when two plates collide and there are three possibilities depending on whether continental or oceanic lithosphere is involved in the process.ivergent Plate Boundaries. The mid-ocean ridges are one of the three basic types of plate boundaries. We call them divergent plate boundaries because the plate material on either side of the margin is spreading apart.