Connate fluids

Connate fluids

The term connate fluids in the context of geology, and of sedimentology in particular, refers to the liquids that were trapped in the pores of sedimentary rocks as they were deposited. These liquids are largely composed of water, but also contain many mineral components as ions in solution.

As rocks are buried, they undergo lithification and the connate fluids are usually expelled. If the escape route for these fluids is blocked, the pore fluid pressure can build up, leading to overpressure.

Significance

An understanding of the geochemistry of connate fluids is important if the diagenesis of the rock is to be quantified. The solutes in the connate fluids often precipitate and reduce the porosity and permeability of the host rock, which can have important implications for its hydrocarbon prospectivity. The chemical components of the connate fluid can also yield information on the provenance of aquifers and of the thermal history of the host rock. Minute bubbles of fluid are often trapped within the crystals of the cementing material. These fluid inclusions provide direct information about the composition of the fluid and the pressure-temperature conditions that existed during diagenesis of the sediments.

Similar, but different in origin, is the concept of fossil water which is used to describe very old groundwater found in deep aquifers or bedrock. Typically it was recharged during a different climatic period (e.g., the last ice age) so is also very old, but possibly not of the same genesis as the rock.

External links

See also


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Sedimentary rock — Middle Triassic marginal marine sequence of siltstones (below) and limestones (above), Virgin Formation, southwestern Utah, USA Sedimentary rock are types of rock that are formed by the deposition of material at the Earth s surface and within… …   Wikipedia

  • Porosity — or void fraction is a measure of the void (i.e., empty ) spaces in a material, and is a fraction of the volume of voids over the total volume, between 0–1, or as a percentage between 0–100%. The term is used in multiple fields including… …   Wikipedia

  • Komatiite — Komatiites are ultramafic mantle derived volcanic rocks. They have low SiO2, low K2O, low Al2O3, and high to extremely high MgO. They were named for their type locality along the Komati River in South Africa. True komatiites are very rare and… …   Wikipedia

  • Diagenesis — In geology and oceanography, diagenesis is any chemical, physical, or biological change undergone by a sediment after its initial deposition and during and after its lithification, exclusive of surface alteration (weathering) and metamorphism.… …   Wikipedia

  • Lithification — (from the Greek word lithos meaning rock and the Latin derived suffix ific ) is the process in which sediments compact under pressure, expel connate fluids, and gradually become solid rock. Essentially, lithification is a process of porosity… …   Wikipedia

  • Scientific drilling — is a way to probe down into the Earth, allowing scientists and students to obtain samples of sediments, crust, and upper mantle. In addition to rock samples, drilling technology allows us to obtain samples of connate fluids and of the subsurface… …   Wikipedia

  • hydrothermal system — GLOSSARY OF VOLCANIC TERMS The system comprising the rocks, fluids, vapors, and conduits associated with hydrothermal activity. In general, hydrothermal systems have the following components: 1) a shallow magma chamber or cooling intrusion… …   Glossary of volcanic terms

  • Water — This article is about general aspects of water. For a detailed discussion of its properties, see Properties of water. For other uses, see Water (disambiguation) …   Wikipedia

  • Magmatic water — or juvenile water is water which exists within and in equilibrium with a magma or water rich volatile fluids which are derived from a magma. This magmatic water is released to the atmosphere during a volcanic eruption. Magmatic water may also be… …   Wikipedia

  • Overpressure — The term Overpressure (Δp) is applied to a pressure difference, relative to a normal or ambient pressure, in various circumstances: In engineering: the pressure difference over the wall thickness of a pressure vessel. It is the overpressure, not… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”