10 most difficult geology riddles A list of ten (out of 46) geology related questions that are the most often answered incorrectly Geology quiz Which desert has this famous "eye"?Sahara. The Richat Structure in Mauritania, also known as the Eye of the Sahara, was interpreted as an asteroid impact structure, but no evidence for shock metamorphism has been found. Today scientists believe that it is a huge (40 km in diameter) and deeply eroded geologic dome.very hard 24% NamibNamib19%GobiGobi31%SaharaSahara24%MojaveMojave24%Created by: globalquiz.org. Statistics based on 7811 answers in 4 languages »deserts of Africa riddles » When did the course of the Baltic Sea coastline finally form?About 2,000 years ago. The Baltic Sea is one of the largest brackish inland seas by area, and occupies a basin formed by glacial erosion during the last few ice ages. It is about 1,600 km (990 mi) long, an average of 193 km (120 mi) wide, and an average of 55 metres (180 ft) deep. The maximum depth is 459 m (1,506 ft).The current course of the shoreline was formed about 2 thousand years ago. very hard 24% about 5,000 years agoabout 5,000 years ago14%about 10,000 years agoabout 10,000 years ago36%about 3,500 years agoabout 3,500 years ago25%about 2,000 years agoabout 2,000 years ago24%Created by: Tschuka. Statistics based on 441 answers in 2 languages »Baltic Sea riddles » Gunung Mulu national park, a place with the most extensive cave system in the world, is located in which country?Malaysia. Gunung Mulu national park is located in the eastern province of Sarawak, Malaysia. It is located on Borneo, near the southern border of Brunei. Gunung Mulu National Park has the largest known natural chamber or room – Sarawak Chamber. It is 700 m (2,300 ft)) long, 396 m (1,299 ft) wide and at least 70 m (230 ft) highvery hard 28% MalaysiaMalaysia28%ThailandThailand24%CambodiaCambodia29%IndonesiaIndonesia17%Created by: Pranav Yalamanchili. Statistics based on 4652 answers in 5 languages »caves riddles » What is the most common element (by mass) forming the planet Earth?Iron is most abundant in the Earth's outer and inner core, and it is the fourth most common element in the Earth's crust.very hard 29% carboncarbon28%oxygenoxygen21%ironiron29%siliconsilicon20%Created by: globalquiz.org. Statistics based on 9303 answers in 3 languages »elements riddles » This is Sable Island, known as the graveyard of the Atlantic. It is about 109 miles southeast of Nova Scotia. What is the island origin?Post-glacial. Sable Island is believed to have formed from a terminal moraine deposited on the continental shelf near the end of the last Ice Age. It emerges from vast shoals and shallows which, in tandem with frequent fog and sudden storms, have caused over 350 recorded shipwrecksvery hard 29% post-glacialpost-glacial29%coralcoral23%volcanicvolcanic19%it is the top of a drowned mountainit is the top of a drowned mountain27%Created by: globalquiz.org. Statistics based on 6678 answers in 3 languages »satellite photos riddles » Sapphire is a blue variety:Of corundum. Sapphire is a gemstone, a variety of the mineral corundum, an aluminium. It is typically blue in color, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors. Pink colored corundum may be either classified as ruby or sapphire depending on locale.very hard 33% of agateof agate30%of chalcedonyof chalcedony21%of corundumof corundum33%of jasperof jasper15%Created by: Tschuka. Statistics based on 880 answers in 3 languages »minerals riddles » Where is the longest cave in Europe located?In Ukraine. Optymistychna Cave (Ukrainian meaning "optimistic") is a gypsum cave located near the Ukrainian village of Korolivka. Approximately 230 km of passageways have been mapped within. As a result, it is the longest cave in Eurasia, the fifth-longest cave in the world and the longest gypsum cave in the world.very hard 34% in Francein France11%in Switzerlandin Switzerland24%in Ukrainein Ukraine34%in Sloveniain Slovenia29%Created by: Ninjai. Statistics based on 129 answers in 3 languages »geography riddles » The hills visible in the picture lie in the Mackenzie delta, in northwestern Canada. What are these terrain forms called?Pingo is a mound of earth-covered ice. Frozen water creates it. These terrain forms are created in areas of long-term permafrost. Most of them lie in the Mackenzie delta.very hard 37% bread rollbread roll21%pingopingo37%fieldfield31%plasneplasne9%Created by: Binsos. Statistics based on 8364 answers in 3 languages »Alaska riddles » Which volcano is known as being one of the most active, but at the same one of the least violent in the world?Kīlauea, Hawaii. Kīlauea is one of the most active volcanoes on the planet and an invaluable resource for volcanologists who are able to study it up close due to its exclusively non-violent effusive activity. Kīlauea lacks a distinct peak and lies close to Mauna Loa.very hard 38% Mt Etna, ItalyMt Etna, Italy21%Kīlauea, HawaiiKīlauea, Hawaii38%Eyjafjallajökull, IcelandEyjafjallajökull, Iceland32%Mt Pinatubo, PhilippinesMt Pinatubo, Philippines7%Created by: globalquiz.org. Statistics based on 11862 answers in 4 languages »Hawaii riddles » What is the typical source of pressure buildup inside a volcano?Degassing of magma. The whole process begins when hot magma is lifted by convection to the magma chamber. As the pressure in the chamber is lower than deep in Earth's crust, the gas starts to release. Since degassed magma has lower density, it may then sink and be replaced with new one. This process may build up huge pressure of gases, eventually causing explosion.hard 40% centrifugal force of Earth rotationcentrifugal force of Earth rotation20%magma convectionmagma convection36%boiling of rainwaterboiling of rainwater3%degassing of magmadegassing of magma40%Created by: Sumit Tamang. Statistics based on 12163 answers in 2 languages »natural disasters riddles » Play geology quiz and see all the questions.