http://gssinternational.co.uk/Docuwiki/ 2026-08-20T12:44:24+00:00 http://gssinternational.co.uk/Docuwiki/ http://gssinternational.co.uk/Docuwiki/lib/exe/fetch.php?media=wiki:logo.png text/html 2023-03-20T09:32:52+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=age_v_zones&rev=1679304772&do=diff Age v Zones Biozones are the primary tool of correlation because they describe what is seen in the rock record. Ages are an interpretation based on the known (at the time) chronological position of the biozone. As has been shown above, the positions of chronostratigraphic boundaries can and often do change. text/html 2023-05-05T15:23:19+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=algae&rev=1683300199&do=diff Calcareous Algae The calcareous algae is an artificial group containing any form of algae which secretes calcium carbonate (in addition to the calcareous nannoplankton described below) and thus can potentially leave a fossil representation of itself. These fossils are most often seen in thin-section preparations of limestones and other well-indurated sediments, used to examine (typically) foraminifera. The group contains green, red and brown algae and also some cyanobacteria. Calcareous algae a… text/html 2023-03-15T08:51:54+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=appraisal&rev=1678870314&do=diff Appraisal When evaluating the extent, capacity and likely geometry of a recently discovered reservoir a more detailed stratigraphic understanding is necessary. By taking a “pragmatic approach” to using fossils as biostratigraphic markers, it is possible to “see in between” the standard global markers and biozones which may not have enough stratigraphic resolution for our purposes. Such local markers may not have an appreciable lateral extent to, say, the regional or even basinal level, but they… text/html 2023-05-05T12:34:52+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=automation&rev=1683290092&do=diff Recording and Managing Data – Automation In Biostratigraphy The sheer volume of data generated by biostratigraphers is extensive. Either generated academically or commercially, the data are stored digitally within numerous software platforms ranging from the simple spreadsheet to complex bespoke databases which include tools for well- or section- management, correlation, chart production and data analysis. There are also extensive web-based facilities which contain useful information on fossil … text/html 2023-05-10T14:41:11+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=biostratigraphy&rev=1683729671&do=diff Biostratigraphy and Biozonation Biostratigraphy has a fairly simple premise… It is less amusingly defined as… “The separation and differentiation of rock units on the basis of the description and study of the fossils they contain” Glossary of Geology text/html 2023-03-19T10:23:12+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=calpionellids&rev=1679221392&do=diff Calpionellids * considered by Armstrong and Brasier (2005) to be related to the ciliated (possessing tiny fronds which beat in waves used for locomotion and food-gathering) Tintinnids which are in turn considered to be protozoa (animals) * hyaline calcareous wall (true tintinnids have organic walls and are discussed herein among the palynomorphs), generally flask shaped text/html 2023-05-05T15:18:59+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=chitinoza&rev=1683299939&do=diff Chitinozoa * unknown biological affinity, “pseudochitinous” wall suggests animal affinities (egg cases?) * unknown marine habitat - floating or attached? * geologic range: Paleozoic (Ordovician to Devonian, rare in Carboniferous) * biostratigraphically significant in the Paleozoic but with relatively few practicing specialists text/html 2023-03-19T17:42:56+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=chronostratigraphy&rev=1679247776&do=diff Chronostratigraphy - Geological Time Scales Chronostratigraphy is the process by which geological time is divided up into meaningful “chunks” of named units. This is hierarchical with categories such as Eons, Eras, Periods, Epochs and Ages/Stages text/html 2023-05-05T14:50:48+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=conodonts&rev=1683298248&do=diff Conodonts * hard parts of early proto-vertebrates (?part of the mouth parts/feeding apparatus) * phosphatic mineralisation * geologic range: Precambrian – Triassic; important fossils for biostratigraphy in Paleozoic rocks * biostratigraphically significant in the Paleozoic but with relatively few practicing specialists text/html 2023-03-20T08:29:53+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=correlation&rev=1679300993&do=diff How Do We Use Biozones? - Correlation Biozones are the primary tools of correlation. If the fossils used to define them have a short stratigraphic range and widespread distribution (see next section) then we can make a basic assumption: The same fossils found in two or more separated sections are contemporaneous (evolution tells us this is so) which means the rocks they are found in are also contemporaneous. text/html 2023-05-05T14:48:46+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=diatoms&rev=1683298126&do=diff Diatoms * green algae (plants) with a siliceous shell – diatoms are the main primary producers in the world’s oceans * can be found as isolated specimens or as a “chain” * a mainly planktonic mode of life within the photic zone * geologic range: Jurassic?/Cretaceous – Recent text/html 2023-05-05T15:17:06+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=dinos_acritarchs&rev=1683299826&do=diff Dinoflagellates and Acritarchs Dinoflagellates (and Acritarchs) are an important constituent of palynological preparations. They indicate marine conditions and are biostratigraphically important. As organic-walled palynomorphs they can also be found in coarser-grained (i.e., higher energy) sediments than other microfossil groups. text/html 2023-09-13T13:36:19+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=et_aquifers&rev=1694612179&do=diff Drinking Water and Biostratigraphy (Aquifers) - an example from Denmark Miocene fluvio-deltaic sands in Jylland, Denmark (see map left, Rasmussen, 1961 & Weinberg-Rasmussen, 1966) are important drinking water reservoirs (aquifers). The water from the subsurface is oxidized to remove manganese and iron and filtered. text/html 2023-09-13T14:12:41+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=et_engineering&rev=1694614361&do=diff Civil Engineering Projects - tunnels etc. The Channel Tunnel The Fehmarnbelt Fixed-Link An 18 km long immersed tunnel is under construction between Denmark and Germany (see www.Femern.com) connecting Lolland, Denmark with the German island of Fehmarn. When complete, it will form the fastest route between Scandinavia and central Europe (Fig below). text/html 2023-06-17T08:40:31+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=et_examples&rev=1686991231&do=diff Examples of Biostratigraphy in the Energy Transition Published examples of biostratigraphy in the Energy Transition are relatively rare but expected to increase all the time. A 2021 Geotechnical study (including microfossil and palynological analysis) of shallow cores offshore Netherlands to establish subsurface environmental maps and correlation for an offshore windfarm proposal (courtesy Dr. John Athersuch, BioChron Ltd.). text/html 2023-07-05T15:06:33+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=et_geothermal&rev=1688569593&do=diff Geothermal Energy and Biostratigraphy - examples from Denmark Geothermal energy is a renewable energy source that originates from radioactive decay and residual heat within the Earth, heat that slowly moves out towards the Earth’s crust and into space. Geothermal energy is an infinite energy source, is not dependent on the weather (unlike solar, wind and wave power) and has a low carbon footprint. In Denmark, the energy can be utilized as hot saline water from geothermal sandstone reservoirs. I… text/html 2023-06-19T12:07:55+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=et_stenille&rev=1687176475&do=diff The Stenlille Structure - a model for CCUS projects in the Danish North Sea Seismic survey acquisition: vibrating trucks,land streamer and wireless stations (Papadopoulou et. al 2022). Denmark is one of the world leaders in the Energy Transition with current focus on CCUS (Carbon Capture, Utilization and Storage). text/html 2023-05-05T14:16:01+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=forams&rev=1683296161&do=diff Foraminifera ("Forams") Forams are single-celled animals (“protista”), heterotrophic (which means they require food from an external source, just like we do) and some are a heterotrophic/symbiotic combination. Think of an Amoeba from your high-school biology class, but with a shell. Most have a mineralised wall of some kind (there are some rare “naked” forms): a secreted wall will be calcareous (calcium carbonate - CaCO3) of various crystal arrangements; an agglutinated wall can be comprised of… text/html 2023-05-05T13:35:42+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=frontier&rev=1683293742&do=diff Frontier Exploration Biostratigraphy and frontier exploration are linked by sequence stratigraphy. Successful play-driven exploration (and production) requires geologists to accurately map reservoir, source and seal facies at the highest resolution possible. In order to do this it is necessary to understand the organisation of the stratigraphic successions you are dealing with at the highest possible resolution. Sequence stratigraphy provides this organisation. text/html 2023-03-20T09:26:44+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=high-res_biostrat&rev=1679304404&do=diff High Resolution Biostratigraphy Of course, it is the goal of every stratigrapher to continuously improve the resolution that their particular stratigraphic tool can resolve. At the individual field level, reservoir units and their associated bounding and/or internal surfaces may lie (stratigraphically speaking) within one standard international or regional biozone. This is because, typically, the depositional events that go to make up a reservoir unit are normally of relatively short duration, … text/html 2023-05-05T15:01:45+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=megaspores&rev=1683298905&do=diff Megaspores Megaspores are parts of some plants' reproductive systems. They are (relatively) large and can sometimes be found in preparations from microfossil samples. They are useful in paleoenvironmental reconstructions but need further investigation to establish their biostratigraphic ranges. text/html 2023-05-05T15:07:30+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=nannofossils&rev=1683299250&do=diff Calcareous Nannoplankton ("Nannofossils") The term “nannofossils” refers to a group of organisms of a size which require the use of a high-powered microscope capable of magnifying around 1000-1500x. Most fossil specimens are around 2-20 microns in size. They are normally examined in thin section preparation by transmitted light with polarisers and a “slow wave” plate. text/html 2023-05-05T14:46:34+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=ostracods&rev=1683297994&do=diff Ostracods * Bivalved Crustacea (related to the modern barnacle but are not attached to any substrate), free swimming but mainly benthonic, very rarely planktonic * geologic range: Cambrian?/Ordovician – Recent (“extant”) * inhabit almost any aqueous environment (even damp woodland leaf litter!) from fresh waters to fully marine (down to abyssal depths) text/html 2023-03-20T10:19:26+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=paleoenv_distrib&rev=1679307566&do=diff The Biology and Distribution of Microfossils Before discussing the specifics of microfossil biology and distribution, it is useful to remind ourselves of the general types of questions we as geologists need to ask ourselves – or the paleontological specialist – when dealing with paleontological data to be used to determine the EOD. text/html 2023-03-20T10:13:39+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=paleoenv_interp&rev=1679307219&do=diff Interpreting Paleoenvironments from Fossils Interpreting paleoenvironments from fossils could be regarded as more of an art than a science. Or perhaps more correctly as a detective story. The evidence and clues will be there but it is how they are put together to form the conclusion that can be the tricky part. We know that certain fossils live(d) in certain environments. Surely if the life habitat maps of each species/genus/group in a particular sample are overlain it will show us the most lik… text/html 2023-03-20T11:08:10+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=paleoenv_sequences&rev=1679310490&do=diff Paleoenvironments and Sequence Biostratigraphy The determination of paleoenvironments from fossils is important for sequence biostratigraphy (see separate section). Rather than identifying specific, individual paleoenvironments for rock intervals, in sequence biostratigraphy text/html 2023-03-20T11:10:17+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=paleoenv_summary&rev=1679310617&do=diff Paleoclimatology and Summary Eustatic sea level rises and falls, particularly when driven by the spread or retreat of polar ice caps and/or glaciated areas, can often be linked to changes in climate. Predominantly dry periods are often associated with increases in ice cover which in turn are often associated with lowstand conditions. Features like the tropical coastal mangrove belts are often reduced or absent. text/html 2023-05-10T14:53:44+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=paleoenv_typical&rev=1683730424&do=diff Typical Environments and Their Fossils Predominantly based on benthonic organisms as these are more responsive to substrate conditions. However, the planktonic component of a fossil assemblage is useful for estimating paleodepths. Foraminifera (both benthonic and planktonic varieties) are the best microfossils to evaluate paleoenvironments. Many foraminifera have reasonably well-known environmental and bathymetric distributions. text/html 2023-03-20T10:06:58+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=paleoenv_why&rev=1679306818&do=diff Why Is This Important? Firstly, depositional regimes – although actually controlled by numerous other factors – are primarily linked to water-depth. Knowledge of the particular depositional regime (e.g. fluvial or turbiditic) of the reservoir may fundamentally affect the way that reservoir is developed and exploited. The internal reservoir architecture can be better defined and internal connectivity pathways can be better predicted. text/html 2023-03-19T10:57:20+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=pitfalls&rev=1679223440&do=diff Other Taxonomic Pitfalls * Older publications may have what are (presently) obsolete genus names but the information attached to that name may still be useful. For example, an important compilation of planktonic foraminifera published in 1985 refers to the species discussed previously as text/html 2023-03-21T11:23:04+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=practical_cons&rev=1679397784&do=diff Practical Considerations Biostratigraphy is making use of fossils to aid in stratigraphic determination, correlation etc. It is unrestricted to the kinds of fossils found in rocks which can of course range from the microscopic to the gigantic (there is a formally defined biozone in the Late Cretaceous of North America defined by a genus of dinosaur!). Common kinds of fossils familiar to most geoscientists as biostratigraphic tools include ammonites, graptolites, trilobites, mammals and, of cour… text/html 2023-03-15T08:59:25+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=production&rev=1678870765&do=diff Production Biostratigraphy is an invaluable part of modern production drilling and it is likely that significant dollar value can be attributed to its use. In fact, biostratigraphy can be utilised in “real-time” operational drilling situations during exploration, appraisal and production phases. The general operational aspect of biostratigraphy is discussed later in this manual. text/html 2023-05-05T14:48:16+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=radiolaria&rev=1683298096&do=diff Radiolaria * single-celled animals (“protista”), like forams but with a siliceous shell * geologic range: Precambrian – Recent * a planktonic mode of life, in fully marine settings * biostratigraphically significant in particular areas/intervals but subordinate to other fossil groups and therefore has relatively few practicing specialists text/html 2023-05-13T14:09:32+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=sample_processing&rev=1683986972&do=diff Sample Processing & Sample Selection All studies in biostratigraphy, no matter the reason, require rock samples from which to obtain the fossils. Some fossils are found whole in the rocks and can be extracted in one piece (hopefully). Microscopic fossils however - those used most often in applied biostratigraphy - require to be text/html 2023-05-05T12:28:20+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=scene&rev=1683289700&do=diff Setting the Scene What is Applied Biostratigraphy? This is biostratigraphy as it is employed not only to help find and produce hydrocarbons, but also the role it plays and will play throughout the Energy Transition. Current uses for CCUS, wind-farm siting, aquifer prediction and mapping etc., although relatively minor at present, will certainly expand many-fold and the principles learned during the past century in the hydrocarbons industry are as equally applicable to the Energy Transition. text/html 2023-05-11T12:36:30+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=seqstrat_characterising&rev=1683808590&do=diff Characterising Sequence Components Using Fossils We need to establish characteristic “paleontological signatures” or “fingerprints” for surfaces and components of a sequence. In order to do that we need to know how the fossils – as living organisms – respond to changes in sea level and, to an extent, sediment supply. text/html 2023-03-20T15:08:10+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=seqstrat_hst&rev=1679324890&do=diff The Highstand Systems Tract (HST) Once the transgression has achieved its maximum landward extent the rate of sea level rise decreases to another stillstand phase and continued sedimentation changes to progradational once again. These parasequences downlap onto the MFS and condensed section further offshore. As the Highstand continues and sea levels begin to fall once again, floodplains inboard of the coastline decrease and rivers can once again direct more sediment onto the shelf. text/html 2023-05-29T14:59:37+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=seqstrat_importance&rev=1685372377&do=diff Why Is Sequence Stratigraphy Important? Sequence Stratigraphy is a way of classifying and arranging sediments based on the relative position of sea level at the time of deposition. Because global eustatic sea level change is cyclic, it is predictable, therefore the distribution of sediments thus deposited are likewise predictable. text/html 2023-03-20T14:34:19+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=seqstrat_lst&rev=1679322859&do=diff The Lowstand Systems Tract (LST) Rivers bring sediments from the hinterland across the now exposed shelf with some rivers cutting deeply into the shelf and slope forming “incised valleys” which act as shelf by-pass channels depositing (relatively) coarser sediment near the base of the slope as a submarine fan (Lowstand Fan). As sea level fall ceases and then starts to rise slowly, submarine fan deposition ceases and is replaced by distal downlapping mudstones of the Lowstand Wedge which progres… text/html 2023-03-20T14:59:48+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=seqstrat_mfs&rev=1679324388&do=diff The Maximum Flooding Surface (MFS) The TST culminates with the MFS – the maximum landward extent of marine conditions. It separates transgressive sediments below from regressive sediments above. It broadly equates to highest relative sea level. It is also the culmination of the condensed section in more distal parts of the basin. text/html 2023-03-20T14:42:29+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=seqstrat_mrs&rev=1679323349&do=diff The Maximum Regressive Surface (MRS) (Sometimes known as the Transgressive Surface (TS) although the two are not strictly the same). Technically this represents the peak regression and offlap at the top of the LST, separating regressive from overlying transgressive sediments. It text/html 2023-03-20T14:27:09+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=seqstrat_sb&rev=1679322429&do=diff The Sequence Boundary (SB) and Correlative Conformity (CC) The SB is formed when sea levels fall and the coastline moves distally across the continental shelf, usually as far as the continental shelf edge. Naturally, countless organisms which previously lived on or in the waters above the continental shelf – one of Earth’s most productive environments – have literally been left high and dry if they weren’t (as species rather than individuals) able to follow the receding waters quickly enough. E… text/html 2023-03-20T14:55:44+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=seqstrat_tst&rev=1679324144&do=diff The Transgressive Systems Tract (TST) As the rate of sea level rise increases after the stillstand/slow increase at the end of LST deposition, the continental shelf begins to be progressively submerged again as the coastline migrates back across the shelf towards the hinterland. Retrogradational parasequences develop towards the inner parts of the shelf and more distal parts of the shelf and slope experience sediment starvation and the onset of condensed sections across the slope and basin floo… text/html 2024-02-21T13:44:36+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=sources&rev=1708523076&do=diff Sources (Written and Online) References In an effort not to overwhelm the course notes with detailed citations and references, those references in bold are considered most suitable for general, non-specialised geoscientific readership. Other references are shown for those wishing to investigate further. DOI links are provided for some references. These were correct at the time of writing but no guarantees can be given as to their current validity. text/html 2023-03-19T10:52:11+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=split-lump&rev=1679223131&do=diff Splitters and Lumpers Scientists – well, palaeontologists at least! – can and do disagree on many things. One thing they do tend to agree on is that it’s nice if you can be the first person to discover or identify a new species. This has led to a trend where some biologists, botanists and palaeontologists can see differences, often very subtle ones, which they use to justify the setting up of a brand new species. This has resulted in (and is recorded in the extensive literature) an increase in … text/html 2023-05-05T15:18:08+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=spores_pollen&rev=1683299888&do=diff Spores and Pollen Spores and pollen are part of the reproductive processes of flowering and non-flowering plants, algae and fungi. Assorted spores and pollen. Spores * the reproductive process of (mainly) algae and fungi – terrestrial and fresh-water origins but very susceptible to offshore transport by river and wind text/html 2023-09-16T09:08:57+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=start&rev=1694855337&do=diff APPLIED BIOSTRATIGRAPHY Supplementary notes to accompany the “Applied Biostratigraphy” course About This Wiki These Wiki pages are designed as a supplementary aid (a kind of “pre-written notebook”) to accompany the Applied Biostratigraphy course. As such it provides additional information on topics covered relatively briefly during the course, including the characteristics of the various microfossil groups, theory and tools for correlation and theory and tools for paleoenvironments. These top… text/html 2023-03-21T09:03:27+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=taxonomy&rev=1679389407&do=diff The Naming of Fossils: Taxonomy “Taxonomy” is the science of naming and classifying living and fossil organisms. Often regarded as one of the most boring aspects of paleontology, taxonomy could never be considered as anything other than a “necessary evil” except to the purists. However, it is one of those “boring but important” subjects that requires some discussion. It is probably the intricacies of paleontological taxonomy (“all those Latin names!”) that has done most harm in making paleontol… text/html 2023-03-21T11:20:53+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=terminology&rev=1679397653&do=diff Terminology Many geologists use terms like “biostratigraphy”, “micropaleontology”, “microfossils”, “nannofossils” etc. freely and interchangeably. This is understandable, but has lead to confusion in the past especially between terms Micropaleontologist and Nannopaleontologist – and the “wrong kind” of biostratigrapher being requested for a particular job. Even for actual practitioners, the term “micropaleontology” can cover numerous meanings. Here are a few informal definitions…… text/html 2023-05-11T10:10:06+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=thermal_maturity_2&rev=1683799806&do=diff Thermal Maturity and Microfossils Often combined with a technique called “Vitrinite Reflectance”, reflectance and other secondary (i.e. imparted) characteristics of microfossils can be utilised as guides to thermal maturity and hydrocarbon generation. Many fossil groups will show, for example, changes in preservational colour with increasing depth of burial/thermal maturity. Sometimes this directly affects the biological material of the fossil itself but sometimes the colour-change is imparted … text/html 2023-05-11T09:25:59+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=thermal_maturity&rev=1683797159&do=diff Thermal Maturity Studies: Source Rocks and Kerogen Types Source Rocks and Organic Maturity Petroleum Systems Analysis is the phase in basin screening and exploration where it is determined if all the necessary elements are in place to generate and trap hydrocarbons. These include elements such as the presence of a source-rock, a reservoir, a trap and a seal but also include quantitative assessments including how much hydrocarbons could be generated from the source rock under different degrees … text/html 2023-03-20T13:11:44+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=tintinnids&rev=1679317904&do=diff Tintinnids * ciliated (“hairy”) protista (animals) * organic-walled, flask shaped * geologic range: very patchy; Ordovician – Recent, abundant in the Jurassic Although organic-walled, tintinnids can sometimes be seen in thin-section preparations when looking at other microfossils (e.g., foraminifera etc.). text/html 2023-03-21T13:15:42+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=wellsite_biosteer&rev=1679404542&do=diff Biosteering Many reservoirs are best exploited by “horizontal” production wells, as far more of the exposed well bore can be located within the reservoir than can be drilled with “conventional” vertical/subvertical wells. In structurally simple reservoirs it is often enough to set up the wellbore aligned to the correct trajectory and simply drill ahead. However most reservoirs are either structurally more complex, or have internal subdivisions which display variable petrophysical parameters whi… text/html 2023-03-20T16:14:29+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=wellsite_geostop&rev=1679328869&do=diff Geostopping Geostopping involves the identification by the biostratigrapher of a specific target horizon based on a specific index fossil or marker species or assemblage of species known to be characteristic of that horizon. Such a target horizon is pre-selected as a proxy at which a desired drilling event is required to happen. Such an event may not necessarily depend on reaching a specific measured depth, but is related to something in the overall geological/stratigraphic setting which effect… text/html 2023-03-20T15:54:23+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=wellsite_monitoring&rev=1679327663&do=diff Geological Monitoring On an exploration well the geological prognosis may be at best rather vague. Biostratigraphy adds certainty to the geological interpretation of drilled formations by providing stratigraphic control using principles and methods described elsewhere on this Wiki, primarily the identification of known “index fossils” to provide accurate calibration to standard timescales. Alternatively assemblages characteristic of known stratigraphic units onshore, or from other wells in a ba… text/html 2023-03-20T18:34:01+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=wellsite_requirements&rev=1679337241&do=diff Requirements for Biostratigraphy at the Wellsite All three major biostratigraphic techniques – micropaleontology, nannopaleontology and palynology – can be carried out at the wellsite to provide “real time” stratigraphic data. As far as the scientific requirements are concerned, these are relatively minimal. The scientist would require working space to sit and use the microscope. text/html 2023-03-20T09:30:33+00:00 Anonymous (anonymous@undisclosed.example.com) http://gssinternational.co.uk/Docuwiki/doku.php?id=which_fossils&rev=1679304633&do=diff Which Fossils To Use? It is difficult to think of a fossil group that has not, at some time, been used to biostratigraphically calibrate a particular rock unit – even human fossils and their various accoutrements and accessories have been used. Nevertheless it has become clear to biostratigraphers that some fossil groups are of more practical use then others in