4. Importance of Microfossils
4
• Microfossils are the most important group of all fossils - they are extremely useful in:
• Geochronology
• Biostratigraphy
• Correlation
• Paleoenvironmental reconstruction
• Paleobatymetry
• Paleotemperature
• Paleocliamte
• Paleoceonography
• Chemostratigraphy
• Sequence stratigraphy
• Environmental geology
• Engineering Geology
5. Applications of micropaleontology
5
1. Applications in sequence stratigraphy.
2. Applications in petroleum Geology.
3. Applications in mineral Geology.
4. Applications in engineering Geology.
5. Applications in Environmental Geology.
6. Applications inArchaeology.
7. Applications in Chemostratigraphy.
6. 6
Introduction to microfossils
Categories of Biozones
Environmental significance
Graphic correlation and duration rates
Conclusion
Agend
a
7. 7
Importance of Microfossils
•Microfossils are the most important group of all fossils - they are
extremely useful in:
•Geochronology
•Biostratigraphy
•Correlation
•Paleoenvironmental reconstruction
•Paleobatymetry
•Paleotemperature
•Paleocliamte
•Paleoceonography
•Chemostratigraphy
•Sequence stratigraphy
•Environmental geology
•Engineering Geology
8. 8
Applications of micropaleontology
1. Applications in sequence stratigraphy.
2. Applications in petroleum Geology.
3. Applications in mineral Geology.
4. Applications in engineering Geology.
5. Applications in Environmental Geology.
6. Applications in Archaeology.
7. Applications in Chemostratigraphy.
9. 1.Applications in petroleum Geology.
1. Applications in petroleum exploration.
a. Chronostratigraphy
b. Palaeoenvironmens.
c. Biostratigraphy
2. Applications in reservoir exploitation.
3. Applications in well-site operations
9
10. Schematic cross section showing rock units from oldest to
Y
oungest with LAD of Hypothetical fossilsA, B, and C noted
Schematic range chart showing the range
of hypothetical fossilsA, B, and C and predict
What will be penetrated by drilling
1
0
11. Biosteering in horizontal well using microfossils in order to
confine the drilling in the reservoir target.
Paleoenvironmental changes during the Paleocene (Danian-
Selandian) in Tunisia from an outer neritic oligotrophic in the
Danian toward a shallower nutrient-rich setting in the Selandian 11
12. 12
Foraminifera
Foraminifera have many uses in petroleum
exploration and are used to:
• Interpret the ages and paleoenvironments of
sedimentary strata in oil wells.
• Agglutinated fossil Foraminifera buried deeply in
sedimentary basins can be used to estimate
thermal maturity, which is a key factor for
petroleum generation.
• The Foraminiferal Coloration Index (FCI) is used
to quantify color changes and estimate burial
temperature. FCI data is particularly useful in the
early stages of petroleum generation (~100°C).
13. 13
Calcareous nannofossils
• These are extremely small objects (less
than 25 microns) produced by planktonic
unicellular algae.
• Coccolithophores, planktonic golden
brown algae that are very abundant in
the world’s oceans.
• The calcareous plates accumulate on the
ocean floor, become buried beneath later
layers, and are preserved as Nannofossils.
14. 14
Palynomorphs
• Spores and Pollens are transported
by wind and water and can travel
long distances before final
deposition.
• Organic chemicals comprising
Palynomorphs get darker with
increased heat.
• Helps to assess the temp. to which a
rock sequence was heated during
burial and thus it is useful in
predicting whether oil or gas may
have formed in the area under study.
15. 15
Environmental significance
Most of the microfauna can be of great help in visualizing the environment
(Provenance) at the time of their deposition.
Examples are:
• Lacustrine environment: diatoms, sponge spicules and also rare occurrence
of foraminifera.
• Littoral environment: we encounter sessile foraminifera and ostracods.
• Lagoonal environment: spores and pollens, conodonts, arenaceous and
porcelaneous foraminifera.
16. 16
Categories of Biozones
• Interval zone
Taxon range zone
Concurrent range zone
and partial range zone
Lineage zone
• Assemblage zone.
• Abundance zone.
21. 2.Applications in sequence stratigraphy.
5
Integated biostratigraphic and sequence stratigraphic interpretation of the Plio-Pleistocene of offshore Egypt. Modified after
Wescott et al. (1998). SB = sequence boundary; TST = transgressive systems tract; MFS = maximum flooding surface; HST =
high-stand systems tract. NDT = Nile Delta Terrace (identified on basis of graphic correlation).
22. 6
Micropalaeontological characterization
of systems tracts in carbonate sequences,
‘Middle’Cretaceous, Middle East
The “Exxon Model” of a sequence and the
hypothetical distribution of benthic and planktic
foraminifera. The planktic foraminifera are most
abundant (and diverse) in the region of the MFS
with deeper-water morphotypes being found in
more distal regions while only surface-water
morphotypes are to be found in more proximal
environments.
23. 3.Applications in mineral Geology using (ESG)
23
Foraminiferal assemblages from sites of ore-body deposition
characterized by environmental stress. enabling an “Environmental
Stress Gradient”. This will serve as pointers to the locations of
hitherto undiscovered ore bodies elsewhere.
25. 4.Applications in engineering Geology
25
Applications in site investigation
• The high-resolution micropaleontology used to keep the trajectory of a
tunnel drilled in chalk between two resistant flint bands.
• Micropaleontology has proved of use in helping to determine the
safest sites for the locations of drilling rigs, pipelines and other
facilities through the avoidance of geo-hazards.
26. Applications in seismic hazard assessment
26
• Rapid changes in bathymetry have been used to infer uplift associated
with past earthquake activity.
• Admixtures of autochthonous marginal marine and allochthonous shallow
to deep marine foraminifera can be used to identify tsunamites
27. 5.Applications in environmental geology
27
• Applications in Environmental ImpactAssessment (EIA).
• Applications in environmental monitoring.
• Applications in environmental anthropogenic activity.
Living Foraminifera and other micro- and macro-organisms have proved of
use in EIA in the civil engineering industry, in the petroleum industry in
baseline studies on the potential environmental impacts of industry projects,
and the mitigation of these impacts.
28. The effects of pollution on the foraminiferal microbiota include:
28
• Modifications to the structure and composition of communities,
including decreases in abundance and diversity, exclusion of
certain species etc…
• Development of test deformities; and changes in shell chemistry,
including increased absorption of metals, and pyritisation.
29. 1: Peneroplis planatus with normal test, Ks-9; 2:
Peneroplis planatus with deformed test, SS-8; 3:
29
Peneroplis planatus with abnormal growth of the
last
formed chamber, SS-7;
protuberances, SS-10; 5: Peneroplis planatus
4: Peneroplis planatus with
with
abnormal growth with the last chamber divided into two
branches, SS-10; 6: Peneroplis planatus abnormal growth
with a new branch of the test, KS-9; 7: Peneroplis
planatus abnormal growth with a new branch of the test,
SS-6; 8: Peneroplis proteus with normal test, SS-10; 9:
Peneroplis proteus with brittle test, SS-10; 10: Clavulina
tricarinata with black spots distributed in whole of the test
(weakly appeared depending on the coating), SS-10; 11:
Clavulina tricarinata curved at the end of the triserial part,
SS-8; 12: Sorites marginalis with normal circular test but
also black, KS-10; 13: Sorites marginalis with abnormal
test elongated, SS-6; 14: Neorotalia calcar with normal
test the spines is preserved, KS-10; 15: Neorotalia calcar
with brittle test and the spines is not preserved, KS-8; 16:
Sorites marginalis with abnormal test and black test, SS-
10.
30. Environmental monitoring of coral reef vitality
30
Living Foraminifera have also used in studies on coral reef vitality using
FORAM Index (FI) provide an indication of water quality and its ability to
support healthy coral reefs :
FI = (10 × Ps) + (Po) + (2 × Ph)
• where Ps is the proportion of symbiont-bearing Larger Benthic Foraminifera
(characteristic of natural, oligotrophic environments)
• Po is the proportion of opportunistic Foraminifera (naturally or artificially
eutrophic environments)
• Ph is the proportion of other Foraminifera
• High FI
• Low FI
favorable for coral reef vitality
unfavorable for coral reef vitality
32. • Foraminifera and other microfossils provide a long-term record of global
environmental and climatic change, including natural as well as anthropogenic
global warming.
• Palaeocene–Eocene Thermal Maximum or (PETM) was relatively rapid,
implying that the present anthropogenic global warming could be,
Global warming
32
34. Stratigraphic distribution of benthic foraminiferal taxa that
disappear in the lowermost Eocene
34
δ13C curve (in bulk sediment) and percentages of CaCO3 and
detritus (silicate minerals). Number of benthic foraminifera
per gram of washed residue 63 µm–1 mm, percentages of
agglutinated and infaunal taxa, and diversity and
heterogeneity indices across the upper Paleocene and lower
Eocene
Onset CIE, BFEE, Excurison taxa, RD assembalges
35. Ocean acidification
35
• Living Foraminifera can used in studies on increasing ocean acidification
in response to increasing, anthropogenically mediated atmospheric carbon
dioxide concentration.
• Calcification, growth and even survival could be adversely affected if the
oceans continue to acidify
37. 6.Applications in archaeology
37
• Foraminifera and other micro- and macro-fossils have been used to provide
information on the stratigraphic and, in particular, palaeoenvironmental –
including palaeoclimatic – context of human evolution,
• They have also been used to provide information as to the provenance of clay
and other materials used in the manufacture of pottery, mosaics and earthworks
• Also to provide information as to the provenance of building and decorative
stone.
38. Archaeostratigraphy
38
archaeostratigraphy, including not only conventional
A number of Quaternary dating methods are available for use in
marine
• micropalaeontological (planktic foraminiferal) and nannopalaeontological
(calcareous nannoplankton), and non-marine palynological (spore and
pollen) but also Marine or Oxygen Isotope Stage (MIS or OIS) stratigraphy.
39. O16
O18
Stable Isotopes
Oxygen
99.76%
0.2%
-1 +
CO2 + H2O = HCO3 + H
-1 ++
2 HCO3 + Ca = CaCO3 + H2CO3
• O18 is preferentially removed from seawater during calcite formation.
• This effect is sensitive to temperature.
• Ratio of O18 / O16 in shell is temperature dependent.
• Can be measured using a mass spectrometer.
7.Applications in Chemostartigraphy
42. Molecular micropaleontology
42
The study of molecular micropaleontology opened up a new
area of further research to get a better insight as to how
climatic change triggers the genetic change responsible for
reproduction and morphology.
43. Fundamental
43
morphogenetic features identified
within Tubothalamea and Globothalamea. A.
Tubothalamea have elongated, tubular chamber(s)
constructed either from the agglutinated organic
composite
composed
(AOC) or the calcitic layer (CL)
of calcareous–organic composite
(porcelaneous tests). The foraminal distance (f–a)
between an aperture (a) and the last foraminum (f) is
maximized; B.Globothalamea show globular or
semi-globular chambers constructed either from
AOC or agglutinated calcareous composite (ACC)
or calcitic/aragonitic layer (CL). The foraminal
distance (f–a) between an aperture (a) and the last
foraminum (f) is minimized. Secondary calcitic
layer (s) is limited to calcareous tests. “Purple”
organic structures (OOL, POS, AOC, ACC) serve as
organic matrix, partly responsible for shaping
chambers.
