FLOODS, FOSSILS AND HERESIES

Unified Hypotheses of the Earth❧ Cosmogonists ● Human search for understanding ● Understanding God through his work Nature and his word Scripture ● All inclusive hypotheses to explain or

FLOODS, FOSSILS AND

HERESIES

“NO VESTIGE OF A BEGINNING,

NO PROSPECT OF AN END”-

JAMES HUTTON

James HuttonFather of Geology

Pre Age of Enlightment

❧ Recognizable evidence of pre-existing life

● Perfect preservation of organisms

● Impressions- casts and molds

● Shells- original or replaced

● Bones- original or replaced

● Plant structures- trunks, leaves

● Trace fossils- tracks, burrows, borings

● Fecal matter (coprolites)

Da Vinci’s Insight

❧ In 1500 C.E Leonardo Da Vinci recognized that

fossil shells in the layered rocks represented ancient marine life

❧ Observed that many fossil rich layers were separated

by unfossiliferous layers thereby repudiating the

concept of one flood

❧ Had the idea that seasonal events responsible

Nicolas Steno

❧ Danish Naturalist and Physician working for the Duke of Tuscany

❧ Widely circulated writings

❧ Fossils formed together with the rocks in which they occur

❧ 1669 stated the 3 most basic principles

❧ Stratification- horizontal layering

● Inferred that differences in strata reflected

differences in conditions (temperature, wind,

currents, storms)

Principles Used to Determine

● Angular unconformity - younger strata overlie

an erosion surface on tilted or folded layers

● Nonconformity - erosion surface on igneous or metamorphic rock

Utility of Fossils

❧ John Woodward

● 1723, Correlation of strata in England and

European mainland based on “great numbers of shells”

❧ Geologic Mapping

● 1746, crude geologic map showed continuity of chalk beneath the English Channel

William Smith, canal engineer

❧ The Map that Changed the World,

❧ 1796 wrote “wonderful order and regularity with

which nature has disposed of these singular

productions [fossils] and assigned to each its class and peculiar stratum”

❧ 1815 Publication of the 1st geologic map of England intended for the development of canals, quarries and mines as well as natural resources

William Smith’s "Strata Identified by Organized Fossils"

❧ Soon after the first issue of his great geological map of England in 1815,

William Smith published the Strata Identified by Organized Fossils

❧ It was intended as a kind of geological users manual with illustrations to identify fossils

❧ But Smith’s work went beyond the mere illustration of fossils Smith had deciphered the hieroglyphics of nature-the distinctive inscriptions borne

by the different strata With the Strata Identified and its colored plates

in hand, anyone would be able to compare the plates with fossils collected

in the field and immediately identify the strata from which they came

❧ The strata once identified, their place in the orderly succession of the

strata-which lay above and which lay below, as Smith had determined it - was then known All this, Smith wrote, "without the necessity of deep reading, or the previous acquirement of difficult arts."

Georges Cuvier and Alexandre Brongniart- Paris Basin

❧ Development of geologic map of Paris Basin

❧ The strata of the Paris Basin were close to horizontal

As of

❧ 1811, Cuvier and Brongniart employed fossils but

only in the few instances where more obvious

evidences of sequence were absent

❧ The title of their work was Géographie

Minéralogique by which they meant the distribution

of what Werner had called the "external"

characteristics of the mineral and fossil contents,

shapes, colors, and textures of the strata within the

Paris basin

❧ Today call this lithology They determined the order

of the strata from their superposition, their lithology and by tracing them across the basin

❧ Cuvier firmly established the fact of the extinction of past lifeforms

❧ Physical Continuity of Lithologic Units

❧ Similarity of Rock Types

❧ Correlation by Fossils

● Principle of Faunal Succession

• Wm Smith & Georges Cuvier

• Organism succeed one another in lithologic strata

• One organism will NOT be found in rocks of widely different ages

● Index Fossil

• Easily recognizable/Easily identifiable

• Wide geographic distribution

• Of limited life span as a species

● Fossil Assemblage

Explanation of Change Among

● Younger organisms are the descendents of older ones

● Species change through time- Charles Darwin

Unified Hypotheses of the Earth

❧ Cosmogonists

● Human search for understanding

● Understanding God through his work (Nature) and his word (Scripture)

● All inclusive hypotheses to explain origin of

universe, earth and life

• Earth originally hot, cooled, water and atmosphere began segregated, interior still hot

❧ Buffon

❧ Geologic Chronology

❧ 18th century thinker

❧ 34 volume Histoire Naturelle, 1749

❧ Molten origin of Earth

❧ Solar system originated from pieces of the sun

breaking of through asteroid collisions

❧ Estimated age of Earth at 75,000 yrs

● Calculated from cooling steel balls

● First to question literal significance of the 6 days of creation, “a year is to God as a thousand years to man”

Geologic Chronology

❧ Buffon’s speculative chronology- 6 distinct epochs

❧ Recognition of rock divisions (coal measures in England by 1719)

❧ J Lehmann distinguishes gently dipping stratified fossiliferous rocks from more ‘primitive’ deposits

❧ 1759 Arduino distinguished Primitive, Secondary, Tertiary and Volcanic

❧ A.G Werner (1787) believed all rocks precipitated from a retreating ocean

● Neptunist

● Primitive, Transition, Secondary and Alluvial

● Considered earth to be static

❧ Basalt Controversy

● Volcanic rock

● Seen to crystallized from lava

● Could not be from a neptunian origin

James Hutton and Plutonism

❧ Dynamic Earth

❧ Earth ever changing

❧ Modern earth processes capable of having produced landscape given enough time

❧ Geologic processes act slowly

❧ Interpretation of basalt as an igneous rock (experiment

The Present is the Key to the Past

Uniformitarianism- Charles Lyell (1830- Principles of Geology) followed James Hutton (1795)

uniform rate of geologic processes

laws of nature do not change with time

Actualism- The Present is the Key to the Past

gradualistic and catastrophic events shape geologic processes

John Playfair (1802) “Amid all revolutions of the globe the

economy of nature has been uniform, and her laws are the only thing that have resisted the general movement The rivers and the rocks, the seas, and the continents have been changed in all their parts; but the laws which describe those changes, and the rules to which they are subject, have remained virtually the same.”

Geology, A Historical Science

❧ Chemistry and physics controlled by universal laws, independent of the time in which they operate

❧ When geologist focus on present processes they

follow applied laws, but when they focus on the past

it is more historical- reconstruction of history based

on biological, chemical and physical laws

GEOLOGIC TIME

Time- the 4th dimension but unlike the spatial dimensions, with time we can only travel in one direction from

present to future

The pre-scientific period

❧ Before 1600 C.E the Biblical account and the speculations of the Greek philosophers were accepted without great question

❧ Archbishop Ussher

● October 23, 4004 B.C.E at 9AM

The era of speculative

cosmogonies

❧ From 1600-1700 C.E a number of comprehensive cosmogonies were proposed

❧ These were long on armchair speculation and short

on substantive supporting evidence

❧ These cosmogonies were part of the new emphasis

of science in seeking rational explanations of the features of the world

The disestablishment of Genesis

❧ From 1700-1780 C.E period marked by a great deal of field geology rather than grand cosmogonies

❧ It became clear that there had been significant changes in the Earth's topography over time and that these changes could

neither be accounted for by natural processes operating during the brief, nor by the postulated Noachian flood

❧ Notable observations included:

● Studies of strata suggested that they were laid down by natural

processes in which the sea and land had changed places several

times Studies of earthquakes and volcanoes showed that the surface crust is subject to massive natural transformation

● Observation of rain, wind, water erosion, and sea erosion in action showed that they were forces capable of reducing mountains and creating valleys

The catastrophist-uniformitarian debate: From about 1780-1850

❧ By the end of the 18 th century it was clear that the Earth had a long and varied history

❧ Interest in major cosmogony was revived

❧ The major debate was between the catastrophists, e.g., Cuvier, who held that the history of Earth was dominated by major

catastrophic revolutions and the uniformitarians, e.g Hutton and Lyell, who held that the history of Earth was dominated by slow relatively uniform changes in an Earth with a static over all history

❧ During the early part of this period there was a considerable amount of activity by scriptural geologists who attempted to reconcile Genesis and geology

The modern period: From 1850 to the present

❧ The great debate was won by the uniformitarians, so much so that the degree of gradualism was

overstated and the importance of catastrophes was unduly minimized

❧ The modern period has been marked by an

enormous expansion of the detailed knowledge of the geological history of the Earth and the processes that have acted during that history

Postulations on the age of the Earth

❧ In 1640 Ussher produced his famous calculation that the Earth was created in 4004 BCE

❧ In the 1700's belief in a 6000 year old Earth crumbled

❧ Attempts to calculate the age of the Earth from physical considerations yielded estimates that ranged from 75,000 years (Buffon, 1774) to several billion years (de Maillet, Buffon)

❧ By the early 1800's it was generally accepted that the

Earth had a long history Its age, however, was scarcely settled

❧ The uniformatarians (Hutton 1788, Lyell 1830) pictured the Earth as being indefinitely old

The Age of the Earth

❧ The catastrophists (Cuvier 1812, de Beaumont 1852, Buckland

1836) accepted that the Earth was old; they disagreed with the kind

of change and the rate of change that had occurred over that long history

❧ There was no single estimate of the Earth's age in the mid 1800's and

no good way to arrive at one

❧ There were various attempts to estimate the Earth's age, working

back from sedimentation rates and other geophysical phenomena The attempts produced estimates from about 100 million years up to several billion years

● There were two major problems with such efforts The first is that the

geological history was still being reconstructed

● The second is that the rates of the physical processes in question are

variable and knowledge of them was incomplete

The Age of the Earth

❧ In 1862 Kelvin estimated the age of the Earth to be 98 million years, based on a model of the rate of cooling This was a minimum

acceptable age consistent with geology Later in 1897 he revised his estimate downwards to 20-40 million years

❧ Kelvin did not know about radioactivity and heating of the Earth's crust by radioactive decay; for this reason his estimates were

completely wrong Likewise, it wasn't until Einstein's theory of

relativity was developed that there was a good explanation of how the Sun could have been shining as long as it had

❧ The first radiometric dating was done in 1905; it and subsequent

measurements confirmed that the Earth was several billion years old Currently the best estimate of the age of the Earth is 4.55 billion years

The Present is the Key to the Past

Uniformitarianism- James Hutton (1795)

uniform rate of geologic processes

laws of nature do not change with time

Actualism- The Present is the Key to the Past

gradualistic and catastrophic events shape geologic

Principles Used to Determine

Relative Age

❧ Cross-cutting Relationships-

Agricola/Lyell

● Truncated units (dikes and faults)

❧ Original Horizontality- Nicolas Steno

● Progressively younger from bottom => top

❧ Lateral Continuity-Steno

❧ Superposition-Steno

Principles Used to Determine Relative Age

❧ Other Time Relationships

● Contact Metamorphism

● Inclusions

❧ Physical Continuity of Lithologic Units

❧ Similarity of Rock Types

Time-Rock Units - rocks formed during a

particular time (lower, middle, upper)

Time Units - defined by distinctive changes in

fossils (Early, Middle, Late)

An age is a unit of geological time which is

distinguished by some feature (like an Ice Age) An age is shorter than epoch, usually lasting from a few million years to about a hundred million years

Rock Units- necessary for geologic mapping

❧ Large enough to show on a map

❧ Distinctive from neighboring rock units

❧ Named after geographic locations

● Separation between 2 distinct rock units

● Sedimentary contact

● Other contacts

A) Angular UnconformityB) Nonconformity

C) Disconformity

❧ The study of layers of sedimentary rocks

❧ The study of rocks lithostratigraphy

❧ The study of fossil content biostratigraphy

Sedimentary Facies developed in the sea adjacent to a land area Front face shows shifting of facies through time

Sedimentation during a regression: Coarsening

Upward Sequence

Walther’s Law- The vertical progression of facies will be the same as the corresponding lateral facies change

A rise or fall in sea level will affect a far greater area along

a low coastline than along coastlines composed of highlands that rise steeply adjacent to the sea

The Vail sea-level Curve: Changes in Global sea-level through time

Standard Geologic Time Scale

❧ Established in the 19th century- Developed by J Phillips 1840 based on work by Sedgwick & Murchinson

❧ Based on Fossil Assemblages

❧ Eons, Eras, Periods, and Epochs

● PHANEROZOIC since 544 m.y.b.p.

• Paleozoic Era 544-245 m.y.b.p.

• Mesozoic Era 245-65 m.y.b.p.

• Cenozoic Era 65 m.y.b.p.-present

❧Precambrian- All time before Paleozoic

http://www.athro.com/geo/timecalc.html