classification of secondary rocks

CLASSIFICATION OF SECONDARY ROCKS                                          

DEPENDING UPON THE DISTANCE OF TRANSPORT AND NATURE OF WEATHERING PRODUCTS:

PRODUCTS OF WEATHERING:    

1.No Transportation:

Weathered product are just near the pre-existing rock.( Red, porous ,gray, pre-existing rock basalt).

 i.e. Residual Deposit

Eg. Latrite, Bauxite                            

2.Transportation:

Transportation take place through atmospheric agencies such as water, wind, glacier.

It is further divided into two part:

(a)Soluble in solution.

(b)Insoluble in solution.

Soluble in solution is further divided into two parts:

1.The material deposited by chemical activities i.e physiochemical process(ppt. evopration). It is also called as CHEMICAL DEPOSIT.

Eg. Limestone (hard, compact, conchoidal fracture).

     Dolomite( when we put drop of acid it give effererence means caco3.)

2.The material deposited by organic activity( biochemical process).

It is also called as ORGANIC DEPOSIT.

Eg.shelly limestone, fossilferrous limestone. It is tested by acid.

Hard part of animals after death accumulate together they extract Ca, Mg salt from water.

It is further classified on basis of composition.

1.     Siliceous deposit: eg. Chalcedony(opal, flint,chert).

2.     Carbonate deposit: eg. Oolitelime, pisolitic.

3.     Ferrugenous deposit: eg.bogiron.

4.     Salt : eg. Chlorine, sulpher, carbonate, nitrate.

It is further classified on the basis of chemical composition:

1.Calcareous Deposit: Shelly limestone, fossilferrous limestone, coral limestone made of caco3. Due to (organisms) chalk , milliolite.

2. Posphatic Deposit: eg. Guano extract phosphatein sea water by organisms.

3.Ferrugenous Deposit: Extract iron in sol by organisms.

4.Siliceous Deposit:eg.radioloria

5.Carboneous Deposit: eg. Peat, lignite, coal.

(b)INSOLUBLE DEPOSIT

CLASSIFICATION BASED UPON GRAIN SIZE DIAMETER.

1.RUDACEOUS DEPOSIT:

Grain size are greater than 2mm diameter.

Eg. Conglomerate (if rounded) ,breccia (if angular).

It shows clastic texture. Ferrogeneous , siliceous cement with pebbles.

2.ARENACEOUS DEPOSIT:

CLASSIFICATION BASED ON CE Grain size are b/w 2 to .1 mm.

Eg. Sandstone.MENT

a.Ferrogenous sandstone:                                                                                 Sand stone contain quartz and feldspar. It shows clastic texture and cemented by various cement.

b.Siliceous sandstone:

c.Calcareous sandstone

d.Argillaceous sandstone

3.Argillaceous Deposit: Grain size less than .001 mm diameter.(clay partical size)

Eg. Shale (lamination layer)

      Mud stone (massive, no layer)

Yellow or gray colour, when we put water on it , it smell first rain clay smell.

5.     Silt deposit: Grain size is lies between 0.1  to .001 mm diameter.

NOTE:

If feldspar is more it is felspathic sandstone.

 If coarse angular grain it is girit.

  If mica is micaceous sandstone. If hard, compact it is quartzite.