This Earthcache will teach you about the formation of an outcrop.
An outcrop occurs when rock is exposed at the Earth's surface because the overlying layer of soil and vegetation is worn away by erosion, tectonic uplift, or human activity. These processes can take place on steep slopes, riverbanks, ridges, mountain peaks, and in tectonically active areas where the underlying bedrock becomes visible.
LOGGING REQUIREMENTS:
Please answer the following questions, to your best ability, using the information above. When you feel you have them answered correctly, send me your answers via the Geocaching websites messaging feature, or through email.
Any "Found It" logs without the requirements being sent in, will be deleted. You can log your find immediately and you must also add a picture of yourself or your GPS (or yoiur mascot) at the location (compulsory).
Tasks:
1) You are here close to the Cittadella of Gozo. Would you say this is an isolated summit, or a part of a range? If part of a range, do you see any other mountain peaks in the area?
2) Based on the look of the rocky outcrops at the posted coordinates, what are the predominant colors?
3) Describe the texture of the rocky outcrops. Are they smooth or rough?
4) Estimate the height of the tallest outcrop. What about it’s width?
5) What could have formed this outcrop?
The EarthCache is outside of the Cittadella of Gozo. Park your car and walk to the EarthCache coordinates.
I hope you enjoyed this EarthCache, and most of all, I hope you learned something new!
Cittadella of Gozo outcrop
The Maltese archipelago, situated between Sicily and Tunisia, was created through the uplift of sedementary rocks, This uplift dates from the late Miocene to the Pliocene. Malta forms the crest of a tilted block on the edge of the Malta Graben.
The geology of Gozo is characterized by marine sedimentary rock, primarily limestone. The islands originated from marine deposits, and the present-day landscape of hills and valleys has been shaped by millions of years of erosion. Tectonic activity has influenced the islands' fracture pattern, resulting in faults.
Gozo consists almost entirely of marine Tertiary limestones that were deposited in shallow waters during the Oligocene and Miocene epochs.
The Oligocene epoch was a geologic time period from about 34 to 23 million years ago, characterized by global cooling, the spread of grasslands, and the emergence of many modern-looking mammals
The Miocene epoch was a geological time period from approximately 23 to 5.3 million years ago, during which global temperatures were generally warmer than today and significant events shaped modern ecosystems and species.
The mountain on which the Cittadella stands is part of Gozo's geological formations, which consist of a variety of rock layers, with limestone being the dominant rock type.
Mountains
A mountain is a large landform that stretches above the surrounding land in a limited area, usually in the form of a peak. A mountain is generally steeper than a hill. Mountains are formed through tectonic forces or volcanism. These forces can locally raise the surface of the earth.
Mountains erode slowly through the action of rivers, weather conditions, and glaciers. A few mountains are isolated summits, but most occur in huge mountain ranges. High elevations on mountains produce colder climates than at sea level. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals.
There are three main types of mountains: volcanic, fold, and block. All three types are formed from plate tectonics: when portions of the Earth's crust move, crumple, and dive. Compressional forces, isostatic uplift and intrusion of igneous matter forces surface rock upward, creating a landform higher than the surrounding features.
The height of the feature makes it either a hill or, if higher and steeper, a mountain. Major mountains tend to occur in long linear arcs, indicating tectonic plate boundaries and activity.
Outcrop
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial deposits are covered by a mantle of soil and vegetation and cannot be seen or examined closely. However, in places where the overlying cover is removed through erosion or tectonic uplift, the rock may be exposed, or crop out. Such exposure will happen most frequently in areas where erosion is rapid and exceeds the weathering rate such as on steep hillsides, mountain ridges and tops, river banks, and tectonically active areas.
Sources:
www.miningscout.de/blog/2012/05/03/was-ist-ein-outcrop/
www.outcropedia.org
https://en.wikipedia.org/wiki/Outcrop