Slate and Marl Types and Facts
Types
Phyllite, Schist, and Slate
Clay Marl ,Blue Marl, Red Marl, High Bank Marl, Shell Layer Marl, Under Shell Layer Marl, Sand Marl, Green Marl, Grey Marl and Clayey Marl
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Generally rough to touch, Is one of the oldest rock, Splintery, Very fine grained rock
Archaeological Significance
Types of Slate and Marl
Some rocks according to their use or texture are classified into different types. Know more about Slate Texture and Marl Texture. Types of Slate are Phyllite, Schist, and Slate whereas the types of Marl are Clay Marl ,Blue Marl, Red Marl, High Bank Marl, Shell Layer Marl, Under Shell Layer Marl, Sand Marl, Green Marl, Grey Marl and Clayey Marl.During historic times, some rocks depending on their hardness were used to create Pictographs and Petroglyphs. Rocks which are hard were generally not used. Pictographs are paintings or drawings that have been placed or created on the surface of rock. Slate and Marl were for creating pictographs. Petroglyph is an image which is carved into a rock. These are images created by removing part of a rock surface by incising, picking, carving or abrading, as a form of rock art. Slate and Marl were for creating petroglyphs.