What is the difference between lineation and foliation

They are described according to their morphological characteristics, and classified into two main groups: continuous foliations and spaced foliations. Several mechanisms thought to be responsible for foliation development are explained and discussed. These are: mechanical rotation of pre-existing grains, solution transfer, crystalplastic deformation, dynamic recrystallisation, static recrystallisation, mimetic growth, oriented growth in a differential stress field and micro folding.

Subsequently, the relation between secondary foliations and axial planes of folds, the XY -plane of tectonic strain and volume change is discussed. The dependence of foliation development from lithotype and metamorphic conditions is also treated. Special attention is given to the practical use of foliations. Since they are present in the large majority of metamorphic rocks they are important reference structures that can commonly be traced between outcrops.

They are especially useful for the establishment of overprinting relations of successive deformation phases. Lineations are another fabric element of major interest. A new subdivision into object and trace lineations is followed in this book. LS: Foliation and Lineation, related to non coaxial strain- shearing. Diorite gneiss 6. This surface is normally striated in the direction of movement. The plane may be coated by mineral fibres that grew during the fault movement, known as slickenfibres, which also show the direction of displacement.

Slickenside on a sample of dextral slickenside of pyrite sandstone Stretched calcite Each layer may be as thin as a sheet of paper, or over a meter in thickness. The word comes from the Latin folium, meaning "leaf", and refers to the sheet-like planar structure. Rocks exhibiting foliation include the standard sequence formed by the prograde metamorphism of mud rocks; slate, phyllite, schist and gneiss.

Fabric elements that define foliations. In each case the foliation is parallel to the top of the block. In all cases an earlier foliation, generally defined by preferred orientation of layer silicates, is folded crenulated on a micro scale. Phyllitic structure is a type of foliation Rocks exhibiting foliation include the standard sequence formed by the prograde metamorphism of mudrocks; slate, phyllite, schist and gneiss.

Total views 20, On Slideshare 0. From embeds 0. Number of embeds 8. Downloads Shares 0. Comments 0. Likes You just clipped your first slide! Clipping is a handy way to collect important slides you want to go back to later. Now customize the name of a clipboard to store your clips. Quartzite is a metamorphic rock from the protolith sandstone. In quartzites, the quartz grains from the original sandstone are enlarged and interlocked by recrystallization.

A defining characteristic for distinguishing quartzite from sandstone is that when broken with a rock hammer, the quartz crystals break across the grains.

In a sandstone, only a thin mineral cement holds the grains together, meaning that a broken piece of sandstone will leave the grains intact. Because most sandstones are rich in quartz, and quartz is a mechanically and chemically durable substance, quartzite is very hard and resistant to weathering. Marble is metamorphosed limestone or dolostone composed of calcite or dolomite.

Recrystallization typically generates larger interlocking crystals of calcite or dolomite. Marble and quartzite often look similar, but these minerals are considerably softer than quartz. Another way to distinguish marble from a quartzite is with a drop of dilute hydrochloric acid. Marble will effervesce fizz if it is made of calcite.

A third non-foliated rock is hornfels identified by its dense, fine-grained, hard, blocky or splintery texture composed of several silicate minerals. Crystals in hornfels grow smaller with metamorphism and become so small that specialized study is required to identify them. These are common around intrusive igneous bodies and are hard to identify. The protolith of hornfels can be even harder to distinguish, which can be anything from mudstone to basalt. Metamorphic rock identification table.

Source: Belinda Madsen Foliation and Lineation Foliation is a term used that describes minerals lined up in planes. Source: Peter Davis Foliated metamorphic rocks are named based on the style of their foliations. Foliation is caused by metamorphism. Bedding is a result of sedimentary processes.