Greetings all
As a newcomer, let me introduce myself. I have just been appointed
lecturer in geology at the Australian National University at Canberra
after 11 years in industry. My current research field is regolith
(everything between fresh rock and fresh air). However I consider
myself a "GP" in geology, with interests in sedimentology, stratigraphy,
palaeoecology, marine geology and ore petrology. I have been a
Christian since childhood and have a long standing involvement in
exploring the interface between science and faith.
I have been lurking on this discussion for some two years although have
occasionally contributed to the parallel ASA group. I was prompted to
come out of the closet by comments by Karen Jensen, who wrote (in part):
There is a time-gap between creation and fossilization, but not between
Precambrian and Cambrian (and most Phanerozoic) fossilization.
The "Cambrian Explosion", instead of being explosive diversification, is
explosive sedimentation.
I am familiar with only one of the many areas in the world where there
is good exposure of the Cambrian-Neoproterozoic boundary. That is in
the Flinders Ranges in South Australia. The Ranges are composed of
sediments of the Adelaide geosyncline, which (from memory) are
approximately 11-15 km thick. The Cambrian makes up the upper 2-3 km of
the succession. There is nothing in the sediments of the Cambrian part
of the succession to indicate that they were the result of "explosive
sedimentation" (whatever that is) or that they were deposited by any
fundamentally different process (bar one) to the sediments of the
Neoproterozoic part of the succession. The exception is the presence of
skeletal fossils in the Cambrian. Almost all the depositional processes
present in the Neoproterozoic are also present in the Cambrian of the
Adelaide geosyncline. Both contain shelf clastics, deep water clastics,
fluvial sediments, alluvial fans, shallow marine, peritidal, and slope
carbonates, evaporites, and deltaic sediments. The exceptions are
lacustrine sediments, ironstones, and glacial and aeolian deposits.
These are found in the Neoproterozoic only. Karen, you are going have
to be more specific: what evidence do you have of "explosive
sedimentation" in the Early Cambrian? What do you mean by such a term?
You also said
....Clearly before the Cambrian Explosion event, but not at any specific
Precambrian horizon. And not with implicit faith in the methods of
dating
Precambrian layers.
What methods of "dating Precambrian layers" do you not have implicit
faith in? Who are you implying has this faith?
In Christ
Jonathan Clarke
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Greetings all
As a newcomer, let me introduce myself. I have just been appointedlecturer in geology at the Australian National University at Canberra after11 years in industry. My current research field is regolith (everythingbetween fresh rock and fresh air). However I consider myselfa "GP" in geology, with interests in sedimentology, stratigraphy, palaeoecology,marine geology and ore petrology. I have been a Christian since childhoodand have a long standing involvement in exploring the interface betweenscience and faith.
I have been lurking on this discussion for some two years although haveoccasionally contributed to the parallel ASA group. I was promptedto come out of the closet by comments by Karen Jensen, who wrote (in part):
There is a time-gap between creation and fossilization, but not between
Precambrian and Cambrian (and most Phanerozoic) fossilization.
The "Cambrian Explosion", instead of being explosive diversification,is
explosive sedimentation.
I am familiar with only one of the many areas in the world where thereis good exposure of the Cambrian-Neoproterozoic boundary. That isin the Flinders Ranges in South Australia. The Ranges are composedof sediments of the Adelaide geosyncline, which (from memory) areapproximately 11-15 km thick. The Cambrian makes up the upper 2-3km of the succession. There is nothing in the sediments of the Cambrianpart of the succession to indicate that they were the result of "explosivesedimentation" (whatever that is) or that they were deposited by any fundamentallydifferent process (bar one) to the sediments of the Neoproterozoic partof the succession. The exception is the presence of skeletal fossilsin the Cambrian. Almost all the depositional processes present in the Neoproterozoicare also present in the Cambrian of the Adelaide geosyncline. Bothcontain shelf clastics, deep water clastics, fluvial sediments, alluvialfans, shallow marine, peritidal, and slope carbonates, evaporites, anddeltaic sediments. The exceptions are lacustrine sediments, ironstones,and glacial and aeolian deposits. These are found in the Neoproterozoiconly. Karen, you are going have to be more specific: what evidencedo you have of "explosive sedimentation" in the Early Cambrian? Whatdo you mean by such a term?
You also said
....Clearly before the Cambrian Explosion event, but not at any specific
Precambrian horizon. And not with implicit faith in the methodsof dating
Precambrian layers.
What methods of "dating Precambrian layers" do you not have implicitfaith in? Who are you implying has this faith?
In Christ
Jonathan Clarke--------------31D750AAACE2216D0A20647A--