GeoPics

30/03/2026

27/12/2025

Geopics # 22

"The Pillow Basalts of Montalban, Rizal"

Rodriguez, Rizal is known for its hiking destinations, caves, and the famous Wawa Dam. However, did you know that there are remnants of underwater volcanism located in the same area?

These are pillow basalts, which are exposed on the right bank of the Wawa River (part of the Marikina River). Pillow basalts are a type of volcanic rock that forms when lava erupts underwater from an underwater eruption. The outer layer cools rapidly, creating a glassy surface, while the interior remains hot and expands, forming rounded shapes that resemble pillows.

These structures can be spherical, bulbous, or tubular, often with a rounded top and a downward-extending tail. Pillow basalts usually contain few gas bubbles (vesicles), which are small cavities left by gases. Those that remain often display a radial pattern due to the quick cooling from all sides.

Some pillow basalts show reddish discoloration due to the oxidation of primary iron-bearing minerals, indicating the formation of ferric iron oxides, most notably hematite. The greenish coloration is attributed to the metamorphic development of secondary hydrous mineral phases, such as chlorite or epidote.

The Pillow Basalts are part of the Montalban Ophiolitic Complex—a section of the Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed above sea level. This is previously known as the Angat Ophiolite, as described by Karig in 1983. The Montalban Ophiolitic Complex is the basement rock (the oldest layer of rock) of the Southern Sierra Madre, and its age is said to be early Late Cretaceous.

References

Mines and Geosciences Bureau Philippines. (2010). Geology of the Philippines. General Books.

U.S. National Park Service. (n.d.). Pillow Basalts (U.S. National Park Service). Www.nps.gov. https://www.nps.gov/articles/000/pillow-basalts.htm

11/12/2025

Geopics # 21
SummerSlam Destination # 3

"The volcanoes of Bataan"

Bataan is renowned for its significant historical role during World War II, most notably as the site of the Bataan Death March. Furthermore, in addition to its historical importance, the province boasts numerous natural attractions, including pristine beaches, scenic waterfalls, and volcanoes, such as Corregidor Island, Mount Mariveles, and Mount Natib.

Both Mount Mariveles and Mount Natib are classified as Quaternary composite volcanoes, indicating their formation during the Quaternary period and their characteristic layered structure formed by successive eruptions of lava and pyroclastic material. As two of the principal peaks that comprise the Bataan Volcanic Arc, these volcanoes are geologically related and collectively shape the topography of the Bataan Peninsula. Although no eruptions have been documented in recorded history, geological evidence confirms episodes of volcanic activity in the past, contributing to the region’s rich volcanic landscape.

Note: This was taken during our Summerslam last April 8-10, 2025 at Morong, Bataan 🐬😎🏄🏻🏖️🌴🌞⛱️🐋🐚

References:

Benguet Corporation. (2024, August 21). Exploration, Research and Development - Benguet Corporation. Benguet Corporation. https://benguetcorp.com/about-us/exploration-research-and-development/

Global Volcanism Program. (n.d.). Global Volcanism Program | Mariveles. Smithsonian Institution | Global Volcanism Program. https://volcano.si.edu/volcano.cfm?vn=273081

Global Volcanism Program. (2024). Global Volcanism Program | Natib. Smithsonian Institution | Global Volcanism Program. https://volcano.si.edu/volcano.cfm?vn=273082

Lagmay, A. M. F., Rodolfo, R., Cabria, H., Soria, J., Zamora, P., Abon, C., Lit, C., Lapus, M. R. T., Paguican, E., Bato, M. G., Tiu, G., Obille, E., Pellejera, N. E., Francisco, P. C., Eco, R. N., & Aviso, J. (2012). Geological hazards of SW Natib Volcano, site of the Bataan Nuclear Power Plant, the Philippines. Geological Society, London, Special Publications, 361(1), 151–169. https://doi.org/10.1144/SP361.13

Mines and Geosciences Bureau Philippines. (2010). Geology of the Philippines. General Books.

Volentik, A. C., Connor, C. B., Connor, L., & Bonadonna, C. (2009). Aspects of volcanic hazard assessment for the Bataan nuclear power plant, Luzon Peninsula, Philippines. Cambridge University Press EBooks, 229–256. https://doi.org/10.1017/cbo9780511635380.010

14/10/2025

Di porket ng-A PO LAKI CALDERA putok na siya...Please Read the post para di na kayo kabahan Salamat!!! 🌋🌋🌋

13/10/2025

Please read this so we won't be fooled by fake news and misinformation. Thank you!

08/10/2025

We express our gratitude to ScienceKonek for the opportunity to share their knowledge about "Space Exploration" not only in Science Techonology Engineering and Mathematics, but across all fields.

Together with Association of Geologists and Geological Engineers of Mapua on the occassion of AGGEM’s Skill Share Workshop #2: The Next Frontier 🚀🌍✨🌌

05/10/2025

Geology is not more about the story in the minerals, rocks, fossils, outcrops, geologic structures, terrane and etc. it's a story of learning, exploration, innovation, discovery and resilience...

A new posting from the Academics Committee Association of Geologists and Geological Engineers of Mapua !

04/10/2025

Meet our speakers coming from ScienceKonek and the Philippine Astronomical Society, Inc. 📚📚📚

30/08/2025

Check out for the First Monthly Posting!!! made by the Acads committee of Association of Geologists and Geological Engineers of Mapua🤓🤓🤓

14/05/2025

𝐖𝐫𝐚𝐩𝐩𝐢𝐧𝐠 𝐔𝐩 𝐒𝐭𝐫𝐨𝐧𝐠 𝐀𝐭 𝐀𝐆𝐆𝐄𝐌! 💎

Yesterday, AGGEM held its wrap-up meeting, bringing together its officers for a final face-to-face meeting for this tenure. Officers discussed plans for the remaining term, recapped past events of the tenure, shared reflections, and enjoyed activities and games.

Keep an eye out for an exciting culmination to Tenure ! We've got some buzz-worthy things coming up! 🐝

08/05/2025

Geopics # 20

"Save and Protect the Karst Landforms of Masungi!"

Karst is a type of landscape characterized by the dissolution of bedrock, resulting in features such as sinkholes, sinking streams, caves, springs, and more. This landscape is primarily composed of limestone (calcium carbonate) and gypsum. Typically, a karst landscape develops when a significant amount of water that falls on the surface interacts with and infiltrates the subsurface through cracks, fractures, and openings eroded into the bedrock. Karst features can be worn away from above or dissolved starting from weak points within the rock.

Located in Baras, Rizal, Masungi Georeserve is a popular tourist spot and protected area outside Metro Manila, where it features a unique Karst landscape including their landforms such as caves. These rocks filter important waterways. Located upstream from Manila, this area helps manage the water flow to the city and Manila Bay. The name "Masungi" comes from the word “masungki,” which means “spiked.”

The Limestones (Masungi Limestone) that are found in the Karst landscape is part of the Maybangain Formation, which was named by Melendres and Versoza in 1960. This formation includes rocks visible along Maybangain Creek, between Sitios Batangas and San Andres in Tanay, Rizal. It is located about 3.5 kilometers north-northeast of Mt. Masungi. You can also find it at the Midland Cement Company quarry, along the Umiray, Limutan, and Makalya rivers, and near the Tanay-Daraitan road.

Despite being protected, the reserve has several problems. These include illegal logging, land-grabbing, quarrying, and violence against forest rangers. Rizal province has many natural resources and is one of the busiest areas for quarrying and mining in the country. Its proximity to the capital attracts businesses, and the land has a long history of illegal occupation and development.

We must protect our natural parks, such as the Masungi Georeserve, not only because of the impressive karst landforms found there but also due to the essential benefits that Mother Nature provides us. Natural parks are vital ecosystems that serve as natural habitats for a variety of plants and animals, and it is crucial to preserve them for future generations.



Note: These pictures came from my classmate, Jan Laurence Marquez (BS Geological Science and Engineering, Mapúa University)

References
Bruce-Lockhart, A. (2024, March 18). The battle for Masungi, a last “ark of biodiversity” in the Philippines. World Economic Forum. https://www.weforum.org/stories/2024/03/masungi-biodiversity-philippines-ann-dumaliang/

Cabrera, J. (2023, February 9). Saving Masungi, a last green corridor of the Philippines: Q&A with Ann Dumaliang. Mongabay Environmental News. https://news.mongabay.com/2023/02/saving-masungi-a-last-green-corridor-of-the-philippines-qa-with-ann-dumaliang/

Masungi Georeserve. (2025). Masungi Georeserve: Award-winning Conservation Project | Day Trip from Manila. Masungi Georeserve. https://www.masungigeoreserve.com/

Mines and Geosciences Bureau Philippines. (2010). Geology of the Philippines. General Books.

National Geographic. (2023). Karst | National Geographic Society. Education.nationalgeographic.org. https://education.nationalgeographic.org/resource/karst/

National Park Service. (2022, April 27). Karst Landscapes - Caves and Karst (U.S. National Park Service). Www.nps.gov. https://www.nps.gov/subjects/caves/karst-landscapes.htm