Glossary for the Geology of Portsdown Hill
A B C D E F G H I J K L M N O P Q R S T U V W XYZ
- A
- absolute dating
- ... (cf 'relative dating')
- accretion
- The addition of continental material to a pre-exiting continent, usually along its edge
- accretionary wedge
- ....
- aerobic
- Using oxygen
- algae
- Deriving from a living organism
- amorphous
- Without form or structure
- anoxic
- Without oxygen
- aeolian
- Wind-blown
- aragonite
- A polymorph of calcite, with no cleavage and higher specific gravity. It is less stable than calcite, so fossils that were originally of aragonite may have converted to calcite, or undergone replacement by some other mineral. (Present-day mollusc shells are composed of aragonite crystals)
- B
- benthic
- Bottom-dwelling
- biogenic
- Deriving from a living organism
- biomineral
- A mineral produced by a living organism, such as chalk (or coal??)
- bioturbation
- disturbance due to organisms moving and burrowing (for example)
- bivalve
- D,,,,
- C
- calcisphere
- need a def
- calcite
- need a def
- calcareous ooze
- need a def
- Campanian
- need a def
- Carboniferous
- The geological period from ~362 to 290 Ma ago
- CCD
- The "carbonate compensation depth" below which calcite (and other carbonates) dissolves, so calcareous ooze does not form on sea floors. Dissolution is due to the combination of high pressure (at depth) and low temperatures. Today, it is at about 4000m in the Atlantic, and only 500m in the colder Antarctica water.
- Cenozoic
- ...
- chert
- need a def
- Breakage of a micro-crystalline mineral (such as flint or obsidian) into a concave curve
- Coccolith
- The calcite plate of a coccolithophore that makes up the Chalk of the hills
- Coccolithophore
- T.......
- cortex
- The lime coating over a flint, that results from interaction between chalk and flint
- Creationists
- God said.....and on the 6th day, He created Man
- Cretaceous
- The geological period from 145 to 65 Ma ago
- cryptocrystalline
- A rock with crystals so fine that they cannot be seen with an optical microscope
- D
- diatom
- .....
- E
- echinoderm
- A class of spiney-shelled invertebrate marine animals, characterised by an internal skeleton of porous calcite plates
- eustatic
- Global
- endoskeleton
- An internal skeleton (cf exoskeleton)
- epoch
- .....
- F
- flint
- Flint is siliceous microcrystalline and found in chalk
- fluvial
- river
- foraminifera
- .....
- G
- GCR
- Geological Conservation Review
- Geological Conservation Review (GCR)
- The GCR was initiated by the Nature Conservancy Council (1977) to assess and document the most important parts of Great Britain's rich geological heritage. Sites were selected based on the importance of the geology shown therein, with an attempt to select those with the most important, exceptional and representative geology. An attempt was also made to avoid repetition, to keep the overall number of sites to a minimum whilst still giving a complete picture. A series of books (including "British Upper Cretaceous Stratigraphy" (R.N.Mortimore, C.J.Wood, R.W.Gallois) details these sites, and each site report is a justification of the particular scientific interest in a locality, of its importance in a British or international setting, and ultimately of its worthiness for conservation.
The Downend Chalk Quarry at Portsdown is one such site. - Globigerina
- foram
- Globigerina ooze
- squidgey stuff
- GMST
- Global Mean Surface Temperature
- H
- hardgrounds
- James Hutton
- The founder of modern geology
- I
- igneous
- invertebrate
- An animal without a backbone. (About 95% of all animal species on Earth are invertebrates)
- isostasy
- J
- Jurassic
- The geological period from ~208 to 145 Ma ago
- K
- kingdom
- Kingdom is at the top of the taxonomic classification, which contains 5 Kingdoms: Animal, Plant, Fungi, Protista and Monera.
- L
- Late Jurassic
- lithification
- Conversion of loose(unconsolidated)sediment into rock, a process which requires much time, pressure and possibly high temperatures.
- lithosphere
- M
- Ma
- Million years (mega-annum)
- mantle plume
- ....
- marine regression
- seas revealing land due to a drop in sea level
- marine transgression
- seas covering land due to a rise in sea level
- marl
- check it
- mass extinction
- A mass extinction is most simply defined as a period of time in which the number of extinctions drastically rises (Raup 801). The extinction of the dinosaurs is a classic example, but this episode is not the only mass extinction recorded in the fossil record. In fact, there are many more, and in recent years several palaeontologists have suggested that these mass extinctions are periodic, or occur in a regular cycle. For more, please read "What Factors May Lead to Periodic Mass Extinctions?" By Steve Brusatte
- metamorphic
- Pre-existing rock, changed by pressure or temperature.
- micrite
- A micro-crystalline calcite, with grain size less than 4µm (aka 'lime mud')
- micro-continent
- micron
- A millionth of a meter, or a one thousandth of a millimeter
- Milankovich
- Milutin Milankovich (1879 to 1958). A Serbian mathematician and physicist who specialized in studies of solar radiation and the orbit of the Earth.
- Milankovich Cycles
- The variation of the Earth's exposure to the sun's rays, or insolation, that results from variations in the orbit of the Earth and the tilt of its axis, and that might affect climate, sea level and sedimentation.
- Monera
- One of the 5 Kingdoms, which contains all the prokaryotes. All members are single-celled and microscopic, and are commonly called "bacteria".
- morphology
- External appearance or form, often used to describe fossils as species.
- N
- nanofossil
- diddy little one
- Nearest Living Relative (NLR)
- ,,,,,
- O
- oolitic limestone
- A non-biogenic limestone formed from ooids (egg-shaped) particles of limestone, that precipitated around nuclei in warm marine water.
- ostracod
- A class of crustaceans, with the body typically enclosed within a bivalved carapace
- oxygen isotope analysis
- well.....
- P
- pelagic
- palaeomagnetic reversal
- The reversal of the magnetic poles, as occurs on average (roughly) every 10 000 years
- photosynthesis
- carbohydrates from sunlight, water and carbon-dioxide
- photic zone
- The water depth to which light penetrates, very dependent of course, but usually to a maximum of 200m. This thus limits the depth of photosynthesising organisms, such as coccolithophores and [....].
- phylogeny
- Organism relationships.........].
- polyzoa
- A phylum of (usually colonial) marine animals, with cup-shaped body, U-shaped food canal, and a wreath of tentacles about the mouth"
- poorly sorted
- A geological term implying a wide range of different grain sizes
- post-depositional
- pressure dissolution
- protozoa
- Single-celled micro-organisms
- Q
- quartz
- Silicon Dioxide
- R
- radiolarians
- silica-based micro-organisms
- replacement fossils
- replacement fossils
- S
- seamount
- Isolated, submarine volcano
- sedimentary
- rocks from pre-existing rock
- silica
- Silica
- siliceous
- siliceous
- spicule
- spicule
- sponge
- sponge
- subduct
- supercontinent
- super plume
- T
- taxonomy
- Taxonomy is the formal classification of organisms (soils, or other entities) based on degrees of relatedness amongst those being considered
- tectonic process
- ....
- terrane
- ....
- tephro-event stratigraphy
- ....
- terrigenous
- Land-derived
- Tertiary Period
- Tertiary Period
- test
- skeleton
- Thomas Henry Huxley (1825-1895)
- super-hero
- till
- A glacial deposit, consisting of a wide range of sizes of chunks of rock and fine-grained, throughly-ground-up rock-flour, that ultimately lithifies to form a consolidated, poorly-sorted rock. It is a sediment laid down by glacial ice, without the intervention of water.
- trace fossil
- Fossil of a mark made by an organism, such as a burrow or track
- tuff
- ....
- U
- Ussher
- James Ussher, Anglican Archbishop of Armagh, Primate of all Ireland, and confident of King Charles I. Using the Holy Bible, he constructed the chronology of the events in the Bible, starting from the creation of the Earth on Saturday, October 22nd, 4004BC. He published his conclusions in 1650 and 1654, and these remained the basis of understanding for many centuries.
- V
- Vendian
- The last system of the Proterozoic, from about 650 Ma ago to the basal Cambrian
- Vine and Matthews
- brits
- W
- (Alfred) Wegener
- germin chappie
- William Smith
- canal engineer chappie
- XYZ
- Glossary test
- you made it!
For any comments, suggestions or contributions, please e-mail me at: portsdown@bbm.me.uk