Turbidite

Classification：Sedimentary Rock

Strictly speaking, turbidite is not a rock type. It is a sedimentary complex composed of mudstone and silty sediments. Turbidite is considered to be formed by turbidite sedimentation.

Turbidite is a general term for all kinds of sedimentary rocks formed by turbidite deposition. The most common ones are Turbidite of hard sandstone, Turbidite of clastic limestone, and various types of turbidity derived rocks. Turbidite and modern turbidite deposits also have vast prospects for deep-sea mineral resources.

Brief introduction:
Turbidite: a sedimentary rock formed by turbidity current deposition.

It is from semi deep to deep sea. According to the composition, it can be divided into: (1) calcium Turbidite. The interbeds are composed of clastic limestone and plaster rock. (2) non calcic Turbidite. It is composed of conglomerate, sandstone, siltstone and shale interbed. On the longitudinal section, it is characterized by the Bauma sequence, that is, the lower coarse-grained part has a grain sequence stratification, which has parallel bedding, and then has flowing sand texture and wrapping bedding, the top has horizontal lamination, and the top is a mudstone without bedding. The bottom of common impression, such as flute mold, mold, mold, mold and other heavy cone, also visible wormholes and imbricate structure. The coarse grains of clastic limestone contain benthic clasts, and plankton grains are found in mudstone and limestone. Generally do not have the rain, mud cracks, rock salt and plant fossils in false root shallow water sediments. Most of Turbidite has flysch formation and flysch formation.

Features：
All kinds of sedimentary rocks formed by turbidite deposits. The most common ones are Turbidite of hard sandstone, Turbidite of clastic limestone, and various types of turbidity derived rocks.
The typical characteristics of Turbidite are as follows: the thicker sand level Turbidite often have size graded bedding. The bedding characteristics become thinner from bottom to top, but all parts are not well sorted, and there are very fine filling materials. The stratification, which is formed by the gradual weakening of water flow, is called separation bedding, which is well divided by various parts. There is no very fine particle in the coarser part of the bottom, and it can be distinguished from the turbidite type of variable bedding. The turbidite sandstone and silty sandstone, is not the development of large and medium-sized cross bedding and ripple preservation. But there are ripple cross bedding and often develop deformable bedding. It mainly reflects the high density and the rapid deposition. (3) all kinds of bottom moulds with prominent shapes are often developed on the bottom of the Turbidite layer. The most prominent feature is the groove. The turbidite head is rich in material with large flow velocity and strong erosion force. It often forms a series of flushing grooves with various directional elongated forms when flowing through the bottom mud surface, and a short time is filled with sand grade and other turbidites, so the mold is formed at the bottom of the sandstone layer and its thin and low end points upstream. It is also common due to the uneven load of unevenly distributed turbidite deposited on the bottom of the mud on the bottom, and some sand is still deep in the mud and forms the load sac in the mudstone layer. There are also hard objects at the bottom of the turbid stream, dragging or jumping on the slightly slime bottom to form sporadic molds, such as groove mold, job hopping, etc. (4) the types of turbidite sandstone are mostly hard sandstones with dark rich clay matrix, showing the characteristics of deep water, turbidity and rapid deposition. (5) coarse clastic rocks in Turbidite generally do not form conglomerates, because mud and sand only form gravel, mudstone, gravel and sometimes gravel bearing limestone.

System:
The generalized turbidite depositional system and Turbidite also include some slump deposits and some other sedimentary gravity flow deposits. It also has slumping Turbidite or sliding Turbidite. In the shallow water area, the waves generated by storm waves become Turbidite, but now they are often classified into storm rocks. The other sediment gravitational flow deposits in these so-called Turbidite or turbidity current depositional systems are not widely distributed, and their lithology often has their own sedimentary characteristics or some typical features of Turbidite. However, its coarse fragments are generally few of the real conglomerates, mostly of conglomerate mudstone and gravelly limestone, and gravel, mudstone, gravel and gravel.

Distribution:
The typical Turbidite layer is often laterally stable, with a distribution area of up to 10 thousand to 100 thousand square kilometers. The cumulative thickness of the active zone is very large, up to hundreds to tens of thousands of meters, and some are called complex stones. Although it is poor in rich mud, poor sorting, or some metamorphism, the reservoir cap assemblage is often formed in the oil field because of the frequent interbedding. In the United States, billions of barrels of oil are produced from Turbidite reservoirs. Turbidite and modern turbidite deposits also have vast prospects for deep-sea mineral resources.