A2 Sedimentary Basins Flashcards
Marginal marine environment
neither marine nor terrestrial, but belongs to both categories, one at low and another at high tide. Often a beach environment.
Land mass
means a continent or large body of land.
Graptolites
extinct marine organisms that lived in colonies, most of which floated freely in the sea, whilst some may have been attached to the sea bed.
Avalonia
was a microcontinent during the Palaeozoic which contained Wales, part of Ireland, England and the southern part of Scotland, located in the southern hemisphere.
Baltica
was a microcontinent during the Palaeozoic which contained the Baltic countries, located in the southern hemisphere.
Laurentia
was a microcontinent during the Palaeozoic which contained northern Scotland and part of Ireland, and the North American continent, located in the southern hemisphere.
lapetus
was an ocean which existed in the Lower Palaeozoic, which closed due to the collision of Avalonia, Baltica and Laurentia microcontinents.
Caledonian Orogeny
was a mountain building era, named after the Latin name for Scotland, Caledonia. The event took place over a considerable period of time, from the Ordovician to the early Devonian.
Terranes
fragments of crustal material broken from one tectonic plate and accreted on another. The boundary, or suture, is usually a fault.
Graptolite Theca
a tube built onto the sicula, in which later members of the colony live.
Graptolite Sicula
a conical structure in which the first member of the colony lives.
Graptolite Stipe
the stack of thecae built up to form a colony.
Viviparous
means producing live young instead of eggs from within the body.
Pycnofibres
filaments that compose the hair of pterosaurs.
Suture
the line along which the septum and the shell fuse.
Ammonite Body chamber
where the animal lived.
Ammonite Protoconch
the initial, embryonic shell in the centre of the coiled animal. New chambers are added onto this as the animal grows.
Ammonite Septal necks
where the septa are pierced to allow a tube of soft tissue through. Septal necks extend to support this tissue.
Ammonite Septum
the wall of the chamber. This is the back wall when it is part of the body chamber.
Ammonite Siphuncle
forms a continuous, delicate tube which connects all chambers.
Ammonite Umbilicus
the diameter of the depression between the inside margins of the last coil.
Belemnites Guard
the solid internal calcite mass that counterbalanced the head. This bullet-shaped component is most commonly preserved. This is sometimes called the rostrum.
Belemnites Phragmocone
are the empty chambers and anterior body chamber within the soft tissue. These chambers are linked together by a siphuncle.
Belemnites Siphuncle
the tube interconnecting chambers in the phragmocone, able to aid buoyancy by altering the amount of gas in the individual chambers.
Belemnites Proostracum
the flattened extension of the guard, which is only occasionally preserved.
