The geology of the Zion and Kolob canyons area includes nine known exposed formations, all visible in Zion National Park in Utah, United States, and representing about 150 million years of mostly Mesozoic-aged sedimentation. Part of the Grand Staircase, the formations exposed in the Zion and Kolob area were deposited in several different environments that range from warm shallow seas, streams, and lakes to large deserts and dry near-shore environments. Subsequent uplift of the Colorado Plateaus exposed these sediments to erosion by swifter streams that preferentially cut through weaker rocks and jointed formations. Much later, lava flows and cinder cones covered parts of the Zion area. Zion National Park is situated on an elevated plateau that consists of sedimentary formations that dip very gently to the east. This means that the oldest strata are exposed along the Virgin River in the Zion Canyon part of the park and the youngest are exposed in the Kolob Canyons section. The plateau is bounded on the east by the Sevier Fault Zone, and on the west by the Hurricane Fault Zone. Weathering and erosion along north-trending faults and fractures influence the pattern of landscape features associated with canyons in this stream-incised plateau region. Read the rest of this article: http://en.wikipedia.org/wiki/geology_of_the_Zion_and_Kolob_canyons_area _______________________________ Today's selected anniversaries: 1768: The first edition of the Encyclopædia Britannica was published. (http://en.wikipedia.org/wiki/Encyclop%E6dia_Britannica) 1922: The Irish Free State came into existence, one year after the signing of the Anglo-Irish Treaty. (http://en.wikipedia.org/wiki/Irish_Free_State) 1957: The Project Vanguard attempt to launch the United States's first satellite was thwarted by a launchpad explosion. (http://en.wikipedia.org/wiki/Project_Vanguard) 1989: Marc Lépine killed 14 women in the École Polytechnique Massacre in Montreal, leading to Canadian gun control laws. (http://en.wikipedia.org/wiki/%C9cole_Polytechnique_Massacre) 1992: The Babri Mosque was destroyed by members of the Vishwa Hindu Parishad and associated groups, believing it was built on the birthplace of Rama. (http://en.wikipedia.org/wiki/Babri_Mosque) _____________________ Wikiquote of the day: "To be a catalyst is the ambition most appropriate for those who see the world as being in constant change, and who, without thinking that they can control it, wish to influence its direction." -- Theodore Zeldin (http://en.wikiquote.org/wiki/Theodore_Zeldin)