The Guaymas Basin is the largest marginal

rift In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben ...

basin located in the

Gulf of California The Gulf of California (), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Vermejo''), is a marginal sea of the Pacific Ocean that separates the Baja California peninsula from ...

. It made up of the northern and southern

trough Trough may refer to: In science * Trough (geology), a long depression less steep than a trench * Trough (meteorology), an elongated region of low atmospheric pressure * Trough (physics), the lowest point on a wave * Trough level (medicine), the l ...

and is linked to the

Guaymas Fault The Guaymas Fault, named for the city of Guaymas, Sonora, Mexico, is a major right lateral-moving transform fault which runs along the seabed of the Gulf of California. It is an integral part of the Gulf of California Rift Zone, the northern extr ...

to the north and the Carmen Fault to the south. The mid-ocean ridge system is responsible for the creation of the Guaymas Basin and giving it many features such as

hydrothermal circulation Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...

and hydrocarbon seeps. Hydrothermal circulation is a significant process in the Guaymas Basin because it recycles energy and nutrients which are instrumental in sustaining the basin's rich ecosystem. Additionally, hydrocarbons and other organic matter are needed to feed a variety of organisms, many of which have adapted to tolerate the basin's high temperatures.

Formation

The formation and characteristics of the Guaymas basin are caused by its location on a mid-ocean ridge system, or a range of underwater volcanoes which occur along divergent plate boundaries.As tectonic plates spread apart,

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...

flows and hardens on the sea floor, creating a new

igneous Igneous rock ( ), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava. The magma can be derived from partial ...

crust. Meanwhile, sediments from the ocean rapidly deposit on top of the crust, building a thick sill cover. The magma spurs

hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...

flow which creates thermal and chemical gradients. These gradients lead to dynamic

biogeochemical Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment (including the biosphere, the cryosphere, ...

environments, which include features such as high heat flow,

plumes, and hydrocarbon seeps, that contribute to the type of ecosystem which thrives in the Guaymas basin.

Hydrothermal Circulation

Hydrothermal circulation, or the circulation of hot water, is a predominant feature of the Guaymas Basin. Hydrothermalism is mainly observed in the southern trough of the basin where

hydrothermal vents Hydrothermal vents are fissures on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hots ...

make up a hydrothermal complex on the seafloor by creating mounds, chimney structures, and sediments. Hydrothermal circulation happens when water flows downward through broken ocean crust along the volcanic

mid-ocean ridge A mid-ocean ridge (MOR) is a undersea mountain range, seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading ...

system. After being heated, the water chemically reacts with the host sill. The temperature of the water can rise above 400°C. At this temperature, the water will rise quickly back to the seafloor due to its decrease in density. This circulation of water is crucial to the cycling of energy and nutrients between the ocean crust and the ocean.

Ecosystem

Especially in the southern trough, the Guaymas Basin supports a unique and vibrant

ecosystem An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

Heterotrophs A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...

consume organic matter rained down from the productive surface waters, while chemolithoautotrophs degrade

hydrocarbons In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic; their odor is usually faint, and may b ...

and oxidize sulfur in the

fluid (often cycling these compounds with

syntrophic In biology, syntrophy, syntrophism, or cross-feeding () is the cooperative interaction between at least two microbial species to degrade a single substrate. This type of biological interaction typically involves the transfer of one or more metabol ...

partners). Of note are the colonies of ''

Riftia ''Riftia pachyptila'', commonly known as the giant tube worm and less commonly known as the giant beardworm, is a marine invertebrate in the phylum Annelida (formerly grouped in phylum Pogonophora and Vestimentifera) related to tube worms ...

'' tubeworms, ''

Beggiatoa ''Beggiatoa'' is a genus of ''Gammaproteobacteria'' belonging to the order '' Thiotrichales'', in the ''Pseudomonadota'' phylum. These bacteria form colorless filaments composed of cells that can be up to 200 μm in diameter, and are one of ...

'' and other

microbial mats A microbial mat is a multi-layered sheet or biofilm of microbial colony (biology), colonies, composed of mainly bacteria and/or archaea. Microbial mats grow at interface (chemistry), interfaces between different types of material, mostly on submer ...

, and

thermophilic A thermophile is a type of extremophile that thrives at relatively high temperatures, between . Many thermophiles are archaea, though some of them are bacteria and fungi. Thermophilic eubacteria are suggested to have been among the earliest bact ...

microbes that can withstand hydrothermal temperatures.

References

{{Central America plates Geology of Mexico Plate tectonics Geography of Mexico Depressions of Mexico