A2 Sedimentary Basins

Question 1

Marginal marine environment

Answer 1

neither marine nor terrestrial, but belongs to both categories, one at low and another at high tide. Often a beach environment.

Question 2

Land mass

Answer 2

means a continent or large body of land.

Question 3

Graptolites

Answer 3

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.

Question 4

Avalonia

Answer 4

was a microcontinent during the Palaeozoic which contained Wales, part of Ireland, England and the southern part of Scotland, located in the southern hemisphere.

Question 5

Baltica

Answer 5

was a microcontinent during the Palaeozoic which contained the Baltic countries, located in the southern hemisphere.

Question 6

Laurentia

Answer 6

was a microcontinent during the Palaeozoic which contained northern Scotland and part of Ireland, and the North American continent, located in the southern hemisphere.

Question 7

lapetus

Answer 7

was an ocean which existed in the Lower Palaeozoic, which closed due to the collision of Avalonia, Baltica and Laurentia microcontinents.

Question 8

Caledonian Orogeny

Answer 8

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.

Question 9

Terranes

Answer 9

fragments of crustal material broken from one tectonic plate and accreted on another. The boundary, or suture, is usually a fault.

Question 10

Graptolite Theca

Answer 10

a tube built onto the sicula, in which later members of the colony live.

Question 11

Graptolite Sicula

Answer 11

a conical structure in which the first member of the colony lives.

Question 12

Graptolite Stipe

Answer 12

the stack of thecae built up to form a colony.

Question 13

Viviparous

Answer 13

means producing live young instead of eggs from within the body.

Question 14

Pycnofibres

Answer 14

filaments that compose the hair of pterosaurs.

Question 15

Suture

Answer 15

the line along which the septum and the shell fuse.

Question 16

Ammonite Body chamber

Answer 16

where the animal lived.

Question 17

Ammonite Protoconch

Answer 17

the initial, embryonic shell in the centre of the coiled animal. New chambers are added onto this as the animal grows.

Question 18

Ammonite Septal necks

Answer 18

where the septa are pierced to allow a tube of soft tissue through. Septal necks extend to support this tissue.

Question 19

Ammonite Septum

Answer 19

the wall of the chamber. This is the back wall when it is part of the body chamber.

Question 20

Ammonite Siphuncle

Answer 20

forms a continuous, delicate tube which connects all chambers.

Question 21

Ammonite Umbilicus

Answer 21

the diameter of the depression between the inside margins of the last coil.

Question 22

Belemnites Guard

Answer 22

the solid internal calcite mass that counterbalanced the head. This bullet-shaped component is most commonly preserved. This is sometimes called the rostrum.

Question 23

Belemnites Phragmocone

Answer 23

are the empty chambers and anterior body chamber within the soft tissue. These chambers are linked together by a siphuncle.

Question 24

Belemnites Siphuncle

Answer 24

the tube interconnecting chambers in the phragmocone, able to aid buoyancy by altering the amount of gas in the individual chambers.

Question 25

Belemnites Proostracum

Answer 25

the flattened extension of the guard, which is only occasionally preserved.