The Earth Story

Ghost Rock

A ghost rock, is it some sort of apparition of a rock from the past? Well yes of sorts. Ghost rock karstification is a two stage erosional process that affects Limestones. The first stage is associated with the chemical weathering of limestone that leaves a ‘ghost-rock’ known as residual alterite. This can only form when there is a low hydro dynamic system allowing for non soluble composition of limestone to remain behind. The second stage is lead by mechanical weathering that erodes away the residual alterite leading to the traditional karstic morphology that is well recognised in limestone areas worldwide. This second stage is associated with a high energy hydrological environment.

Gorgeous area - travel to the landscapes of Myanmar in this drone video. Original caption:

Tre Cime di Lavaredo The 3 peaks of Lavaredo (also called Dre Zinnen/3 chimneys), seen here in the mists, are some of the most famous peaks in the Alps. They are located in Northwest Italy, in the province of South Tyrol. The highest of them, Cima Grande (big peak) in the center reaches 2999 meters above sea level. As they’re some of the key peaks of the Dolomites, it is no surprise that the rocks making up these towers are in fact dolomite, a carbonate mineral. 

Gypsum tumulus in Germany The great Jurassic limestone platform that covers much of Western Europe was born when the sea levels were higher due to the breakup of the supercontinent Pangaea. As new oceans opened at the nascent spreading ridges, entire ocean basins rose due to the buoyancy imparted by the heated roiling mantle below that was fuelling the supercontinental split. This meant in practice that much of the land was covered by sea as the water was pushed out of its basins in very slow motion, and these ubiquitous limestones and the younger Cretaceous chalk (as in the White Cliffs of Dover) are the most obvious remnants of this process.