The Globigerina Limestone
How Geocaching Works
Use of geocaching.com services is subject to the terms and conditions in our disclaimer
Malta's reference rock rock is actually a plant?
Malta is basically a lump of limestone in the Mediterranean and only covers just over 300 square kilometres (including the outlying islands of Gozo and Comino).
Being a rocky lump it has stone absolutely everywhere. It boasts what is reputedly the world's oldest free-standing dry stone temple, Ggantija on Gozo; dry stone walls everywhere; and a plethora of active and disused quarries, dating back to Roman times. Most of the quarries (including more modern ones) are little more than rectangular holes (deep, but small coverage) carved out of the rock, and the number has to be seen to be believed.
Malta has two types of limestone, globerigina and coralline. The globerigina (mostly to the south) often found as large flaky slabs, is a softer rock, relatively easy to work and has formed the bulk of Malta's building material over the years. The harder, more crystalline, coralline stone found more to the North and on Gozo has been used on the more important buildings.
in http://www.dry-stone.co.uk/Pages/Books/Articles/Malta/Malta.html, visited in Nov 2013
The sedimentary rocks forming the Maltese geological sequence are lime-rich, being predominantly limestones. This is due to the fact that the deposits consisted mainly of skeletal remains such as shells and shell fragments, dead fish and plant detritus all of which are lime-rich, essentially consisting of calcium carbonate. This is evidenced by the abundant and clearly visible fossils within the strata. The properties of the layers depend on the grain size of the sediment as well as its layering, the depth of deposition, the fossils residing within it, any disturbances caused by organisms during the time of formation as well as any changes following deposition. For instance if a layer is made up of fine particles with no large ones, this indicated that deposition took place at a large depth with little or no agitation by waves. The fossil remains also shed light upon the organisms that may have inhabited the layer. From these revelations we can then infer whether the sea bed at the time was within light penetration, and hence at a shallow depth or at large depths with little penetration of light.
The Globigerina Limestone
This is a softer fine grained rock layer than that below it and therefore, when weathered, it forms gentle slopes. The thickness of the Globigerina layer varies between 20 metres near Fort Chambray, Gozo to about 200 metres at Marsaxlokk, Malta. This layer’s texture is homogeneous, unlike the Lower Coralline. The composition of the Globigerina Limestone is entirely Globigerina and related deep-sea micro-organisms, which indicates that at the time of its formation 34 million years ago, a sinking of the land mass took place since the components suggest sea-depths of around 600 feet. The variation in thickness of the layer also illustrates that a warping of the sea bed took place. The homogeneity of the layer further illustrates that deposition took place in deep waters with little agitation and wave action upon it.
in https://www.um.edu.mt/science/physics/smru/generalinformation/geologyofmalta, visited in Nov 2013
The Cache is located in an area surrounded by many quarries that used to be active in the removal of the Limestone for building purposes. Looking around, you can see many man-made cuts in the high Limestone walls that were used to cut the precious material out. The Cache means to celebrate the Maltese Limestone and the Maltese landscape.
Ng gur raq bs gur pehzoyvat jnyy, jryy pnzbhsyntrq :) Qb lbh erzrzore gur 'bcra frfnzr' fgbel?
Last Updated: on 6/19/2017 11:41:10 AM Pacific Daylight Time (6:41 PM GMT)
Coordinates are in the WGS84 datum