The term pelagic refers to the open ocean, and in the context of sedimentology, pelagic sediments are made up of suspended material that was floating in the ocean, away from shorelines, and has settled on the sea floor..or refers to the water column beyond the shelf break, overlying the slope and the deep-sea bottoms, generally with water depths greater than 200 m and down to more than 10 000 m.

thanks Dr.Ahmed .could we called for shiranish formation as a pelagic sediment

In deep water, the pelagic zone is sometimes called the open-ocean zone and can be deep water more than 200 m.

thanks dr.falah. is a pelagic relared to living manner or sedimentary environment.

I think both together

Dear Colleagues:

Pelagic can be used in a quadripartite way (1) lacustrine, (2) oceanographic/ biological, (3) depositional and (4) lithological.

(1) In a lacustrine environment it stands for the deeper parts of a lake > 10 to 20 m characterized by fine-grained sediments like mud and by the absence of aquatic vegetation

(2) It reflects the wide open ocean in oceanographic and biological terms with organism living not at the sea bottom but nektonic or planktonic

(3) The terrigenous part derived from the continent has been significantly diluted leaving behind only suspended matter for settling down. In this case also the word abyssal is applied. Magmatic and hydrothermal sediments/deposits may also be placed under this header

(4) In carbonate petrography the technical term is used for fine-grained limestones composed of fine-grained floating tests, in other words of the organism described under (2). The shelf break is in this case no longer used as a boundary for the environment of formation/deposition. It covers the open marine environment.

With kind regards

H.G.Dill

thank you very much.but how magmatic and hydrothermal deposits . just from their grain size or textures or whats.

The pelagic environment is also characterized by magmatic rocks and by hydrothermal deposits, e.g., black smokers. I hope this will contribute to clarify your question.

H.G.Dill

Dear Dill

Im very happy and precipitated to you and your contribution.

regards

Deep deposition, open water, (sea or ocean) caractrized with fine grained and quiet energy of sedimentation....

thanks Dear Jaloul