And now for something very different:
Evidence that banded iron formations formed very rapidly
and a proposed YE correlation.
Enjoy the food for thought in this extraordinary period we are all experiencing!
Analytical Profile of Coleus Forskohlii | Forskolin .pptx
Banded iron formations formed rapidly
1. Banded Iron Formations
formed rapidly
Based on paper:
http://www.journalofcreation.com/journalofcreation/2017_volume_31_issue_2?pg=16#pg16
2. Geological history is forensic science. Cannot “prove” the past, as if it was a
mathematical exercise. Thus all of us, even atheists, live by faith.
Complexity
• May be several constructive models to explain the same aspects of past geological
history. Need to be humble. Easier to pull down a model than to construct one.
• Great need for more networking by interested and experienced Young Earth (YE)
geos to build better constructive models.
However, aim to propose models to:
• be consistent with observations in the present (eg rocks, chemical makeup).
• take into account one’s worldview eg Scripture reliable when it speaks of history.
• recognise assumptions about past processes and their rates.
Disclaimer: this is presented in a private capacity only, not as a representative of my
employer.
INTRODUCTORY REMARKS
3. • Over 95% of the world’s iron
resources occur in BIFs.
• The principal source of iron for the
global steel industry.
ECONOMIC SIGNIFICANCE OF BIFS
4. GEOGRAPHIC OCCURRENCE OF BIFS
Widespread geographically in Precambrian provinces
Figure
modified
from
Bekker
et al.
2010
5. CHARACTERISTICS OF BIFS
• Chemical sedimentary rock.
• Chemical composition unlike any sedimentary material being deposited in significant
quantities on the modern Earth.
• Alternating bands of iron oxide and chert. Principal iron oxides hematite & magnetite
- individual bands may vary in thickness from < 1 mm to meters.
• Overall succession of bands may be hundreds of meters thick.
6. TIME OF BIFS
• Archean and Paleoproterozoic provinces principally.
• Mesoproterozoic provinces (1.0-1.6 Ga) lack BIFs.
• Neoproterozoic provinces have a few smaller occurrences.
Figure
modified
from
Klein
2005
7. ALGOMA-TYPE
3 main BIF types - Algoma, Superior and Rapitan,
named after locations in Canada.
Algoma-type
• in volcano-sedimentary sequences of greenstone
belts, chiefly of Archean “age”
• stratigraphically linked to or interlayered with
submarine-emplaced volcanic rocks &, in some cases,
with volcanogenic massive sulfide (VMS) deposits
• typically rarely extend for more than 10 km along
strike & are less than 50 m thick.
• Algoma-type and Superior-type iron formations are
similar in mineralogy
• Eg: Canadian & Western Australian greenstone belts
http://www.sandatlas.org/banded-iron-formation/
8. SUPERIOR-TYPE
• Globally, by far the most economically important type
of BIFs.
• Large in size: > 100 km lateral extent & > 100 m thick.
• Situated in relatively undeformed continental margin
sedimentary basins around time of the Archean -
Proterozoic boundary that have unconformable
contacts on granite-greenstone terrains.
Eg
• Hamersley Basin of Western Australia
• Transvaal of South Africa
http://www.sandatlas.org/banded-iron-formation/
9. RAPITAN-TYPE
• Interbedded with what is commonly
interpreted in mainstream articles as
Neoproterozoic “glacials”.
• In extensional grabens associated with initial
breakup of Rodinia supercontinent
• Commonly found in association with mafic
volcanics
Examples
• Rapitan of NW Canada
• Urucum region of Brazil
Figure from Baldwin 2014
10. HAMERSLEY BASIN, WA
• Superior-type BIF.
• One of world’s largest areas of BIFs.
Outcrop area ~ 100,000 km2.
• Extraordinary lateral stratigraphic &
chemical continuity of BIFs on a variety of
scales.
• microbands (~ 1mm thick) can be
traced for 100s of km.
• broad alternation & concordance of
BIFs with other sedimentary rocks
(mainly shale & carbonate) & volcanics
(including “dolerite” & rhyolite) easily
recognised over whole outcrop area
Figure from Partridge et al. 2008
11. IGNEOUS ACTIVITY
• Giant early Precambrian iron formations - episodic deposition associated with large
igneous provinces (LIPs).
• Neoproterozoic BIFs also associated with periods of intense magmatic activity.
• Evidence that Hamersley Basin BIFs formed along with pulses of intense volcanism
(including emplacement of a large igneous province comprising > 30,000 km3 of
volcanic rocks) driving a period of enhanced submarine hydrothermal activity.
• Emplacement of enormous volume of volcanic rocks is beyond anything happening
in today’s world e.g. Mt St Helens, 18 May 1980 erupted only 1.2 km3 ash.
• Description of high energy processes (huge & intense volcanic activity with enhanced
hydrothermal activity)
• in stark contrast to description in same paper of BIF deposition rate being
compared with gentle rate of settling of fine sedimentary particles in modern open
ocean! (Barley et al. 1997)
12. BIF DEPOSITION 1
Early models
• slow deposition of annual micro-laminations (chemical varves) over millions of years
(Garrels 1987).
Modern interpretations
• iron & silica sourced from reactions between circulating deep sea water & hot mafic
to ultramafic rocks as hydrothermal systems vented onto the sea floor.
• hot acidic hydrothermal fluids would immediately precipitate colloidal particles of iron
hydroxide & iron silicates on quenching by cold neutral seawater.
• episodic & rapid deposition of turbidity & density currents may have only lasted a few
hours to days! (Lascelles 2013)
13. BIF DEPOSITION 2
Chemical makeup, common fine lamination, and the lack of detrital components in
early BIFs suggest that they resulted from
• deposition as chemical sediments
• below wave base, in the deeper anoxic parts of ocean basins.
Rare-earth element profiles of almost all BIFs, with generally pronounced positive
Europium anomalies, indicate that
• deep ocean hydrothermal activity admixed with sea water was the source for the
precipitation of the iron and silica (Klein 2005).
14. LABORATORY STUDIES
• Colloidal solutions rapidly precipitate into regular
and ordered bands
• Rate of chemical reactions increases
exponentially with temperature increase
- why various mineral assemblages &
petroleum can form rapidly under hydrothermal
conditions.
• High temperature fluids are capable of
extracting & transporting large quantities of silica
& iron from mafic igneous rocks
Figure from George and Varghese 2005
15. YE FRAMEWORK – EARLY CREATION WEEK
“Now the earth was formless and empty, darkness was over the surface of the deep,
and the Spirit of God was hovering over the waters.” (Genesis 1:2 NIV)
• Earth had its first global ocean (the deep) on Days 1 & 2, before the gathering of
waters & appearance of land on Day 3 (Genesis 1:2-10)
• In Genesis 1:2 the Earth would have appeared from space like a relatively smooth
formless watery ball, without obvious features or landmarks such as mountains
protruding above the water.
“Or who shut in the sea with doors when it burst out from the womb” (Job 38:8 ESV)
• A common iron oxide mineral in BIFs is hematite (Fe2O3) and this may have
appeared blood-coloured as if from the womb.
• It is inferred that the earlier Precambrian iron formations (Algoma and Superior-
types) formed early in the Creation Week by catastrophic pouring out of volcanics
and associated banded iron formations.
16. YE FRAMEWORK – EARLY FLOOD
• The second & only other global ocean was during the peak of Noah’s Flood (Genesis
7:19-20).
• Rapitan-type iron formations are interbedded with Neoproterozoic mixtites (detrital)
and these mixtites are considered to represent mass flows (not glacials) early in
Noah’s Flood.
• Geochemical data indicate that Neoproterozoic iron formations result from mixing
between a hydrothermal and detrital component, while rare earth element data
indicate substantial interaction with seawater.
• Hydrothermal component provided by Flood’s fountains, that rifted open the
supercontinent.
• Detrital component provided by erosion of land caused by the Flood’s rain.
17. CONCLUSIONS
• Modern evidence indicates that BIFs formed rapidly in deep water by catastrophic
precipitation from volcanic and associated silica-rich & iron-rich hydrothermal fluids.
• Young Earth (YE) model correlation with Bible’s two occasions of globe-covering
ocean:
• early Precambrian BIFs formed in early Creation Week
• late Precambrian BIFs formed in initial Noah’s Flood (rift & rain phase).
• BIFs are clear-cut examples of non-uniformitarianism in the Earth’s history:
• modern analogues are unknown
• BIFs are restricted in time to the Archean, Paleoproterozoic and Neoproterozoic.
For references see:
http://www.journalofcreation.com/journalofcreation/2017_volume_31_issue_2?pg=16#pg16
18. GEOLOGICAL MODELS imperfect but useful
"Essentially, all models are wrong, but some are useful."
--- Box, George E. P.; Norman R. Draper (1987). Empirical Model-Building and Response Surfaces, p.
424, Wiley.
"All models are wrong"
every model is wrong because they are a simplification of reality.
[ie not perfect and not comprehensively complete]
"But some are useful"
simplifications and approximations of reality can be quite useful.
[Whereas too much complexity and people can get lost in the detail]
They can help us explain, predict and understand the universe and all its various components.
Aim for consistency between the various items of evidence (eg geological maps and Bible verses), to
come up with geological history models.
Test various competing models for consistency with the evidence.
Editor's Notes
The aim of this presentation is to ….
General comments about geological history models.
BIFs are economically important since over 95% of iron resources of the world occur in BIFs. They are the principal source of iron for the global steel industry.
BIFs have been found on all continents except Antarctica.
Giant (100,000 billion tons or more) BIFs are located in South Africa, Australia, Brazil, Russia and Canada.
More large BIFs are found in many other places including in the USA, India, Ukraine, and China