In geology

Geology

Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...

, tectonostratigraphy refers either to rock sequences in which large-scale layering is caused by the stacking of thrust sheets or nappes in areas of thrust tectonics

Thrust tectonics

Thrust tectonics or contractional tectonics is concerned with the structures formed, and the tectonic processes associated with, the shortening and thickening of the crust or lithosphere.-Deformation styles:...

 or the effects of tectonics on lithostratigraphy

Lithostratigraphy

Lithostratigraphy is a sub-discipline of stratigraphy, the geological science associated with the study of strata or rock layers. Major focuses include geochronology, comparative geology, and petrology...

.

Tectonically formed stratigraphy

One example of such a tectonostratigraphy is the Scandinavia

Scandinavia

Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...

n Caledonides. Within the entire exposed 1800 km length of this orogenic belt

Orogeny

Orogeny refers to forces and events leading to a severe structural deformation of the Earth's crust due to the engagement of tectonic plates. Response to such engagement results in the formation of long tracts of highly deformed rock called orogens or orogenic belts...

 the following sequence is recognised from the base upwards:

• Autochthon

undisturbed foreland of the Baltic plate

Baltica

Baltica is a name applied by geologists to a late-Proterozoic, early-Palaeozoic continent that now includes the East European craton of northwestern Eurasia. Baltica was created as an entity not earlier than 1.8 billion years ago. Before this time, the three segments/continents that now comprise...

• Parautochthon

thrust sheets that have moved only a short distance (up to 10s of km) from their original position

• Lower allochthon
  Allochthon
  thumb|right|250px|Schematic overview of a thrust system. The hanging wall block is called a [[nappe]]. If an [[erosion]]al hole is created in the nappe that is called a [[window |window]]...
  
  

far travelled thrust sheets derived from the Baltic plate passive margin

Passive margin

A passive margin is the transition between oceanic and continental crust which is not an active plate margin. It is constructed by sedimentation above an ancient rift, now marked by transitional crust. Continental rifting creates new ocean basins. Eventually the continental rift forms a mid-oceanic...

, mainly sediments associated with the break-up of Rodinia

Rodinia

In geology, Rodinia is the name of a supercontinent, a continent which contained most or all of Earth's landmass. According to plate tectonic reconstructions, Rodinia existed between 1.1 billion and 750 million years ago, in the Neoproterozoic era...

• Middle allochthon

also derived from the margin of the Baltic plate, Proterozoic

Proterozoic

The Proterozoic is a geological eon representing a period before the first abundant complex life on Earth. The name Proterozoic comes from the Greek "earlier life"...

 basement and its psammitic

Psammite

Psammite is a general term for sandstone. It is equivalent to the Latin-derived term arenite. Also, it is commonly used in various publications to describe a metamorphosed sedimentary rock with a dominantly sandstone protolith. In Europe, this term was formerly used for a fine-grained, fissile,...

 cover

• Upper allochthon

thrust sheets including island arc

Island arc

An island arc is a type of archipelago composed of a chain of volcanoes which alignment is arc-shaped, and which are situated parallel and close to a boundary between two converging tectonic plates....

 and ophiolitic sequences

• Uppermost allochthon

thrust sheets containing sediments with fossil assemblages indicating an origin on the margin of the Laurentian plate

Laurentia

Laurentia is a large area of continental craton, which forms the ancient geological core of the North American continent...

This vertically stacked sequence thus represents the passive margins of Baltica and Laurentia and intervening island arcs and back-arc basin

Back-arc basin

Back-arc basins are geologic features, submarine basins associated with island arcs and subduction zones.They are found at some convergent plate boundaries, presently concentrated in the Western Pacific ocean. Most of them result from tensional forces caused by oceanic trench rollback and the...

s telescoped together and emplaced on top of the Baltic Shield

Baltic Shield

The Baltic Shield is located in Fennoscandia , northwest Russia and under the Baltic Sea. The Baltic Shield is defined as the exposed Precambrian northwest segment of the East European Craton...

, involving hundreds of km of shortening.

Within this overall stratigraphy the individual layers have their own tectonostratigraphy of stacked thrust sheets.

Effects of active tectonics on lithostratigraphy

Tectonic events are typically recorded in sediments being deposited at the same time. In the case of a rift

Rift

In geology, a rift or chasm is a place where the Earth's crust and lithosphere are being pulled apart and is an example of extensional tectonics....

, for instance, the sedimentary sequence is normally broken down into three parts:

• The pre-rift includes a sequence deposited before the onset of rifting, recognised by the lack of thickness and sedimentary facies changes across the rift faults.
• The syn-rift includes a sequence deposited during active rifting, typically showing facies and thickness changes across the active faults, unconformities
  Unconformity
  An unconformity is a buried erosion surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger, but the term is used to describe...
  
   on the fault footwalls may pass laterally into continuous conformable sequences in the hanging walls.
• The post-rift includes a sequence deposited after the rifting has finished, it may still show thickness and facies changes around the rift faults due to the effects of differential compaction and remnant rift topography, particularly in the earliest part of the sequence.

This relatively straightforward nomenclature may become difficult to use, however, in the case of multiphase rifting with the post-rift from one event being the pre-rift to a later event.