Rock art is a rather vague term which denotes prehistoric man-made markings on natural stone. Similar terms include: "rock carvings", "rock engravings", "rock inscriptions", "rock drawings" and "rock paintings". This type of Stone Age art is traditionally divided into two main categories: 1 Petroglyphs : meaning, rock engravings or carvings; this category also includes works of prehistoric sculpture that are part of the rocks themselves known as parietal art , such as relief sculpture. While these petroglyphs and pictographs have been found on the walls of caves, or on exposed outdoor sections of rock, in practice, the earliest art of Europe was created in subterranean caves, while in say Northern Africa it is found mostly on the surface of the ground. A third, smaller category of rock art is associated with Megaliths or Petroforms , involving the arrangement of stones to create a type of monument eg. Stonehenge stone circle.
What types of rocks can be used for radiometric dating
Radiometric dating methods | Geology (modification for Lehman College, CUNY)
Natural Disasters Tulane University Prof. Stephen A. Nelson Meteorites, Impacts, and Mass Extinction. On February 15, a meteor exploded in the sky over Chelyabinsk, southern Russia. Although the Chelyabinsk meteorite probably weighed about 12,—13, metric tonnes, and measured 17 to 20 m in diameter before it exploded, sientists were quick to point out that it was very small compared to other objects that could potentially hit the earth. The explosion released energy estimated at about kilotons of TNT about 20 to 30 times more energy than the Hiroshima atomic bomb.
Radiometric dating of rocks and minerals
Stratigraphy , scientific discipline concerned with the description of rock successions and their interpretation in terms of a general time scale. It provides a basis for historical geology , and its principles and methods have found application in such fields as petroleum geology and archaeology. Stratigraphic studies deal primarily with sedimentary rocks but may also encompass layered igneous rocks e.
Remote sensing in geology is remote sensing used in the geological sciences as a data acquisition method complementary to field observation , because it allows mapping of geological characteristics of regions without physical contact with the areas being explored. First, the intensities of reflectance at different wavelengths are detected, and plotted on a spectral reflectance curve. This helps geomorphological studies of ground motion, and thus can illuminate deformations associated with landslides , earthquakes , etc. Remote sensing data can help studies involving geological mapping, geological hazards and economic geology i.