Gumdrop Seamount is a small

seamount A seamount is a large submarine landform that rises from the ocean floor without reaching the water surface (sea level), and thus is not an island, islet, or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abruptly a ...

( underwater volcano) located on the flank of Pioneer Seamount, off the coast of

Central California Central California is generally thought of as the middle third of the U.S. state of California, north of Southern California (which includes Los Angeles and San Diego) and south of Northern California (which includes San Francisco and San Jose, ...

. It is the northernmost of the related seamounts in the region, which includes Davidson,

Guide A guide is a person who leads travelers, sportspeople, or tourists through unknown or unfamiliar locations. The term can also be applied to a person who leads others to more abstract goals such as knowledge or wisdom. Travel and recreation Exp ...

Pioneer Pioneer commonly refers to a person who is among the first at something that is new to a community. A pioneer as a settler is among the first settling at a place that is new to the settler community. A historic example are American pioneers, perso ...

, and Rodriguez seamounts. It is defined by a series of aligned cones, the majority of which are poorly defined, separated by troughs filled with sediments. The largest cone rises to within of

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

. It is estimated to have a volume of about , but the poorly defined base hinders observations of its size. Samples recovered from Gumdrop are highly vesicular in origin, and include alkalic basalt,

hawaiite Hawaiite is an olivine basalt with a composition between alkali basalt and mugearite. It was first used as a name for some lavas found on the island of Hawaii. It occurs during the later stages of volcanic activity on oceanic islands such as Ha ...

, and

mugearite Mugearite () is a type of oligoclase-bearing basalt, comprising olivine, apatite, and opaque oxides. The main feldspar in mugearite is oligoclase. Mugearite is a sodium-rich member of the alkaline magma series. In the TAS classification of volc ...

; however, their ages have yet to be determined.

References

Seamounts of the Pacific Ocean {{marine-geo-stub