Paleoecological and Paleobiogeographical Studies of Eocene Benthic Foraminiferas

7/28/2019 Paleoecological and Paleobiogeographical Studies of Eocene Benthic Foraminiferas

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Paleoecological andPaleobiogeographical Studies of

Eocene Benthic Foraminiferas ofthe Salt Range and Hazara Area


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Paleoecological andPaleobiogeographical Studiesof

EoceneBenthic Foraminiferasofthe Salt Range and Hazara Area


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Paleoecology

Paleoecologyis study of the causes of patterns of distributionand abundance of ancient organisms.

Concerned with the interactions between individuals and theirphysical and chemical environments, interactions betweenindividuals of the same species and between species.

Paleoecological perspectives are an expanded view of ecologythat considers how organisms (individuals, populations, andcommunities) have responded to abiotic and biotic factors overlong intervals of time.


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Paleoecology: branches and scope

Ecological studies focus on individual species. e.g.population ecology.

Ecological studies focus on many species. e.g. Communityecology.

To unreveal the history of the earth and its inhabitants.

To solve the presentday ecological problems.


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General Concepts

The concept ofuniformitarianism, has played apart in the interpretation of paleoeocological data.

This idea is applicable to strata deposited since theLate Proterozoic, when metaphytes and metazoans

first evolved. Limitations


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General Concepts

Analogy involves the application of modernorganismic features to ancient organisms.

This principle may be applied to individuals (withregard to form and function), community structure(species diversity, organizational and trophic

structure), and population dynamics (response totime-independent environmental factors).


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General Concepts

Parsimonyinvolves the use of the simplest, or mostparsimonious, explanation to decipher the data.

That is, the explanation that uses the fewest steps,beginning with the cause, through the intermediatecauses, responses, and effects to the final result, is the

most desirable when interpreting the information.


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Species

diversity

Species richness

Species eveness

Information function

Ficher alpha index

The number of species present.

A measure of the distribution ofindividuals among species in anassembalge.

H = -piln (pi) Hmax(S) = ln(S)

E = eH

/S Hayek and Buzas (1997)

J = H/ln(S) Pielou (1966)

A measure of species diversity basedon a log-series distribution.


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Graph to determine values of Fisher diversity, from thenumber of species and number of individuals in anassembalage.


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Summary of species-diversity data showing the fields for the main values

Fisher alpha

H


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Fig. Summary of ternary plots of walls .A= agglutianted, P= porcelaneous, HyHyaline

Marginal Marine

Shelf seas

Deep Sea


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Biogeographical Studies (the distribution oforganism, present and past) and the historical and

ecological processes that cause these distribution area natural extension of systematics.

As we proceed downward to the lower member of

systematic hierarchy, discreet distribution emerge.

Biogeography


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Biogeography

Recognition of patterns of distribution andattempting to explain them is the domain of

biogeographer.

Biogeographical studies are essentials tobiostratigraphy.

Immensity of the subject.


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Distribution of (a) cold water and (b) warm water benthic foraminifera faunas(after Cushman, 1948)

a

b


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Methodology

Collection of samples in the field.

Fossils Separation.

Identifications. Statistical measurements.

Graphical presentation of statistical measurements.

Interpretation. Results .

Paleoecological and Paleobiogeographical Studies of Eocene Benthic Foraminiferas

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