Question: How old is the currently active shield volcano located in the Kaʻ ū Desert?
Context: Tweed Volcano is a partially eroded Early Miocene shield volcano located in northeastern New South Wales, which formed when this region of Australia passed over the East Australia hotspot around 23 million years ago.  Mount Warning, Lamington Plateau and the Border Ranges between New South Wales and Queensland are among the remnants of this volcano that was originally over 100 km in diameter and nearly twice the height of Mount Warning today, at 1156 m .  Despite its size, Tweed Volcano was not a supervolcano; other shield volcanoes - such as on Hawaii - are much larger.  In the 23 million years since the volcano was active, erosion has been extensive, forming a large erosion caldera around the volcanic plug of Mount Warning.  Its erosion caldera is the largest in the Southern Hemisphere. Tamu Massif is an extinct submarine shield volcano located in the northwestern Pacific Ocean.  The possibility of its nature as a single volcano was announced on 5 September 2013, which, if corroborated, would make Tamu Massif the largest known volcano on Earth.  It is located in the Shatsky Rise about 1600 km east of Japan.  Its summit lies about 1980 m below the surface of the ocean, and its base extends to a depth of about 6.4 km .  The volcano is about 14620 ft tall. Māhukona is a submerged shield volcano on the northwestern flank of the Island of Hawaiʻ i.  A drowned coral reef at about 3,770 feet (-1,150 m) below sea level and a major break in slope at about 4,400 feet (-1,340 m) below sea level represent old shorelines.  The summit of the shield volcano was once 800 feet (250 m) above sea level.  It has now subsided below sea level.  A roughly circular caldera marks the summit of Māhukona.  A prominent rift zone extends to the west.  A second rift zone probably extended to the east but has been buried by younger volcanoes.  The main shield-building stage of volcanism ended about 470,000 years ago.  The summit of the shield volcano subsided below sea level between 435,000 and 365,000 years ago. The Kaʻ ū Desert is a leeward desert in the district of Kaʻ ū, the southernmost district on the Big Island of Hawaii, and is made up mostly of dried lava remnants, volcanic ash, sand and gravel.  The desert covers an area of the Kīlauea Volcano along the Southwest rift zone.  The area lacks any vegetation, mainly due to acid rainfall. Emuruangogolak is an active shield volcano straddling the Gregory Rift in Kenya, in Eastern Africa.  It has a 3.5 x caldera on its summit.  The last known eruption was a trachyte flow which occurred in 1910.  Steam vents and fumarolic activity continues from fissures within the caldera and along the flanks of the volcano.  Several maar lakes exist in the rift valley adjacent to the volcano.  The volcano's summit is at 1328 m elevation, and its formation is calculated to have been 38,000 years ago. Kebeney (Russian: Кэбеней ) is a shield volcano located in central Sredinny Range, in the northern part of the Kamchatka Peninsula, Russia.  It is a basaltic/andesidic shield volcano with a number of cinder cones on its flanks, aligned along the Sredinny Range NE-SW axis. Tendürek (Turkish: "Tendürek Dağı" , Armenian: Թոնդրակ, Tondrak ) is a shield volcano located in the Ağrı and Van provinces of eastern Turkey, close to the borders with Iran.  The elongated volcano rises 1800 m above the Doğubeyazıt plain, south of Mount Ararat.  Two main cones with a crater each and several minor lateral cones form the edifice.  The edifice dates 700,000–500,000 years BP to 13,000 BP and is mostly constructed from basaltic lavas, with some pyroclastics and trachytic/trachyandesitic lavas.  It has a volume of more than 300 km and covers a surface area of about 650 km.  Pyroclastic cones with basaltic lava flows on the eastern side of the mountain are around 2,500 years old.  The last known eruption may have been a gas and ash eruption in 1855, and hydrothermal systems exist on the volcano.  Since 1993, the volcano has been subsiding in a ring fault.  The Armenian name for the mountain was Tondrak; the area around the mountain was the birthplace of the medieval Armenian Tondrakite Movement of the 950s, which based its ideology on Paulician teaching. The Barrier Volcano is an active shield volcano located in the north of Kenya.  It is last known to have erupted in 1921. Newberry Volcano (with Newberry Caldera) is a large potentially active shield volcano located 40 mi east of the Cascade Range and about 20 mi southeast of Bend, Oregon, within the Newberry National Volcanic Monument. Kīlauea ( , ; ] ) is a currently active shield volcano in the Hawaiian Islands, and the most active of the five volcanoes that together form the island of Hawaiʻ i.  Located along the southern shore of the island, the volcano is between 300,000 and 600,000 years old and emerged above sea level about 100,000 years ago.  It is the second youngest product of the Hawaiian hotspot and the current eruptive center of the Hawaiian–Emperor seamount chain.  Because it lacks topographic prominence and its activities historically coincided with those of Mauna Loa, Kīlauea was once thought to be a satellite of its much larger neighbor.  Structurally, Kīlauea has a large, fairly recently formed caldera at its summit and two active rift zones, one extending 125 km east and the other 35 km west, as an active fault of unknown depth moving vertically an average of 2 to per year.
Answer: between 300,000 and 600,000 years