Mag-Aso Falls
The Mag-aso Falls in Antequera is 20 km from Tagbilaran. The fall drops 10 m with lush vegetation around it.
The Mag-aso Falls is one of Bohol’s natural treasures. With a height of 25 feet, the twin falls is picturesque against a backdrop of tall trees, wild plants including giant ferns, and deep ravines. Once on the site, while bathing and surrounded by the natural landscape, one feels immersed in a middle of a jungle with the sound of the interminable chirping of the birds and the rush of flowing waters playing music to your ears. The falls can be found in barangay Mag-aso.
There are 197 concrete steps with metal handrails leading down to Mag Aso Falls and it is an easy 5 to 10 minute hike to reach the bottom.
At the halfway mark on the way down to Mag Aso Falls, there is a viewpoint that overlooks the waterfall which makes for a great panorama view of the twin cascade.
Carved out under the waterfall is a natural pool that is particularly inviting to go for a swim due to its milky blue colored water derived from the limestone rocks in the area.
It is alleged that the Mag-also came from the local word or a Bisaya term “Aso”, which means “smoke”. It is because, the strong drop of the water from the lush green forest as a backdrop has created drizzles that resemble smoke. Snuggled in the forested area of Barangay Can-omay, Antequera, Bohol and being maintained by the Antequera Local Government Unit (LGU).
Geology
Bohol as island province has a total land area of 411,726 hectares with 654 kilometers of coastline. The Island Province of Bohol is predominantly a sedimentary island. It developed from the magmatic, tectonic mechanism that resulted from the underthrusting of the southwest Philippine Plate east of Samar and Surigao. Ongoing erosion, transport and sedimentation continue to accumulate marine and terrestrial deposits in the Bohol basin.Bohol is composed of 11 rock formations that exhibit differentlandforms.
Carmen and Maribojoc formation constitute the biggest with 34 percent of the total area in Bohol. It is followed by Boctol serpentinite periodotite constituting 14 percent and sierra bullones limestones of 10 percent. The rest are Alicia schist, alluvium, Jagna andesites, Talibon diorite, undefferentiated andesite basalt lava flows and wahig orbotoid limestone ranging one percent and below.
The oldest rock formation belongs to the Basement Complex particularly found at the eastern flank of the island. Because of the sub-crustal movements like faulting, seven different geomorphologic landforms were produced, namely the Anda Peninsula, Loon Peninsula, Northwestern Area, Central-Northern Sedimentary Area, Eastern Volcanic, Limestone-Haycock Hills and Central Volcanic.
The major part of the island of Bohol occupies the southeastern portion of the Visayas sea basin. The basement rocks underlying Bohol are composed of metamorphic and ultramatic rocks. These types of rocks are found in the eastern part of the province, which roughly defines a north-northeast alignment. In the southwest is an ophiolite-metamorphic belt with a similar trend that extends from Zamboanga to Sulu Islands. The pre-tertiary diorite plutons in Bohol are believed to be representatives of a southeast facing arc system related to inactive northeast trending trence, a segment of which is defined by the associated ultramatic-metamorphic rock assemblages in the province (see Geologic Mapand Figure).
Types of Rocks
There are three types of rock on Earth: Igneous, sedimentary, and metamorphic. Some things on Earth are different because of the way they look or feel. Rocks come in all shapes, sizes, and colors, though, so we can't use the way they look to tell the difference. The thing that makes each type of rock different is the way it is made. One is made when hot lava cools down and hardens. One is made when sand or other small pieces get stuck together. One is made when a rock gets buried deep and heated up a lot.
Igneous Rock Type
Igneous rocks are formed when magma cools and turns into a rock. This cooling can either be intrusive, where the magma pool gradually cools and the magma solidifies into an igneous rock. Alternatively, the cooling can extrusive, where the magma is cooled very quickly such as during a volcanic eruption.
Igneous rocks are the "new kids" in the rock cycle. They're the new rock on the block, ready to start fresh.
Sedimentary Rock Type
Sedimentary rocks are made up of pieces of older rocks (igneous, metamorphic, and sedimentary) and organic remains (shells, bone, etc.). When rocks break apart from erosion they are transported by rivers and streams to lakes and oceans. As the sediment piles up it is compressed and heated in the Earth. Eventually, the high pressures and temperatures lithify the loose sediment into a sedimentary rock. More information on sedimentary rocks.
Sedimentary rocks are the "recyclers" of the rock cycle, they take any other rock and turn it into a new one.
Metamorphic Rock Type
Metamorphic rocks form from a previously existing rock, be it igneous, sedimentary or even an older metamorphic rock. Rocks turn metamorphic when they are subjected to very high heat and pressure. This alters the chemical and structural makeup of the minerals within the rock, changing it into a new metamorphic rock. If the rock is heated enough, it fully melts and if cooled would be an igneous rock.
Metamorphic rocks are the "change makers" of the rock cycle. They take what was once a rock and change it into a new rock!
Maribojoc Limestone & Carmen Formation
Bohol Island is predominantly a karst terrain underlain by limestone. The Maribojoc Limestone, Sierra Bullones Limestone, and Wahig Limestone are the carbonate rock units that underlie the southern and central portions of the Island. These rock units are characterized as poorly bedded, porous, marly, rubbly, coralline cream to buff. Meanwhile, the southeast Bohol area is underlainby pillow basalts, serpentinites, and schists comprising the Bohol Ophiolite complex. Volcanic and plutonic rocks comprising the Jagna Andesite, Ubay Volcanics, Ilihan Plug, and Talibon Diorite are distributed in the northern and central portions of the Island.
The province is underlain by a variety of unconsol-idated and consolidated sedimentary, igneous, andmetamorphic rock units ranging in age from pre-Cretaceous (basement complex) to Recent (alluvium). More than 70 per-cent of the province is underlain by sedimentary rocks and most of the Antequera area is under-lain by the Maribojoc Limestone, a prolific carbonate rockaquifer system.
The Maribojoc is a transgressive reefal limestone of Upper Pliocene–Pleistocene Age. It is “usually softand porous and light cream to pinkish in color on fresh surfaces and dirty white to gray when weathered”. In this area, the Maribojoc is characterized by gentlyundulating to rolling topography, and two plateaus with aver-age elevations of about 50 and 30 meters above mean sea level.The area is criss crossed by numerous karst depressions (dolines).
The Maribojoc Limestone exhibits numerous sinkholes,caves, and caverns and the hydraulic conductivity of thisaquifer system can be very high where there are extensivefracture and solution openings. Dissolution in these rocks hasproduced secondary permeability, which results in locally highyielding wells and springs. Well yields are quite variable fora given area and can range over several orders of magnitude.Run-off occurs only during periods of very intensive rainfall;otherwise most rainfall directly recharges the underlying carbonate rock aquifer systems.
The Carmen Formation is distributed mainly in the eastern part of Bohol occupying 30 to 40 percent of the total island area. This low dipping thick sedimentary sequence is essentially composed of shale, sandstone, slabby to massive limestone, conglomerate, siltstone, marl and some Tuffaceous and siliceous facies. This formation to be Middle to Upper Miocene. However, samples obtained during this survey yielded fossils from Early to Middle Miocene. The conglomerate of this formation occurs around Dimiao, the southern coast and along Tanguhay River
Questions :
1. Looking at the walls of the pond and waterfall, tell if you are in the presence of Igneous Rock Type, Sedimentary Rock Type, Metamorphic Rock Type.
2. Are you in an area of Maribojic Limestone or Carmen formation on this site and why?
3. While observing the bottom of the pool (you have to dive or snorkel), describe in your own words what you see.
4. Please upload a picture of you or your gps of this beautiful place. Please do not include pictures of underwater in your log. (This is a requirement starting 6/11/19 and is supported by new Earthcache guidelines).
5. Please send the answers to be by message on my profile. You may log the Earthcache as found. I will contact you if your answers are incorrect. If I do not receive answers within a reasonable amount of time (~7 days) I may delete your log.