Precambrian Plant Fossils and the Hakatai Shale Controversy
Volume 36(3):106-113 December 1999
Within the global uniformitarian stratigraphic timescale, plant fossils have been found in Precambrian strata dated to approximately 3.5 billion years in age. Evolutionists have not successfully explained when or how life formed to produce these ancient and wide-spread plant fossils. Young-earth creationists have also investigated Precambrian plant fossils, focusing primarily on Precambrian rocks found in the Grand Canyon. Controversy has developed around the plant fossil content of the 1.25 billion year old Hakatai Shale. Several studies suggest that modern and ancient fossilized plant material might be present within the shale. Other Precambrian stratigraphic units in the Grand Canyon contain plant fossils. Precambrian strata of much greater age than the Hakatai Shale are known to contain plant fossils. However, some young-earth creationists have rejected the presence of plant fossils in the Hakatai Shale, or in abundance in any other Precambrian strata. This position is not required by either uniformitarian or creationist frameworks and it ignores documented evidence of Precambrian plant material. The author proposes that Precambrian plant fossils exist, and reflect the effects of the global Flood on Antediluvian sediment and plant material. However, only the additional study of plant fossils within the various Precambrian outcrops at each locale can determine their specific position within the young-earth Flood model stratigraphic column.
Many creationists have generally followed the framework of the global uniformitarian timescale in attempting to define geologic history within a biblical time frame. Weaknesses in this approach, however have led several young-earth creationists to propose other Scriptural methods of understanding strata (Froede, 1995, 1998; Froede and Reed, in press; Reed and Froede, 1997; Reed, Froede, and Bennett, 1996; Walker, 1994). This foundational change in defining Earths history offers a different solution to many seemingly complex issues. One of these is the presence of plant fossils within Precambrian strata. These fossils have been a perplexing problem for some creationists, but one which can be resolved within a new biblical framework.
Uniformitarians continue to collect evidence of fossilized plant life further and further down their global stratigraphic column. Creationists can and should assist in this search, but for different reasons. The presence of Precambrian fossils has created controversy for uniformitarians and creationists. One specific stratigraphic unit, the Hakatai Shale of the Grand Canyon, has been a focus of investigation and controversy among creationists. Why is identifying plant fossils within this shale layer considered a problem by some, and what bearing does it have on the creationist approach to understanding earth history? Some background about these supposed ancient plant fossils is necessary.
Precambrian Plant Fossils
Uniformitarian geologists divide the Precambrian into two Eons: the Proterozoic, and the underlying Archean (Figure 1). Proterozoic strata have yielded plant fossils which have been investigated for more than one hundred years (Hofmann, 1971; Link et al., 1993; McMenamin and McMenamin, 1990). For some uniformitarians, life did not exist when the underlying Archean strata were deposited because the atmosphere was not believed to have contained sufficient oxygen to allow aerobic life to have formed or developed (Cloud, 1968; 1976; 1983; Knoll, 1992). This concept has recently been challenged with physical evidence of aerobic plant fossils in Archean rocks. At present, uniformitarians have reported plant fossils in 3.4 to 3.5 billion year old (commonly abbreviated Ga) Archean strata in Australia and South Africa (Margulis, 1988; McNamara and Long, 1998; Read and Watson, 1975; Schopf and Walter, 1983; Schopf, 1994; Strother, 1989; Walter, 1983). According to Schopf (1994, p. 193), evidence of plant life in the Early Archean consists of:
...(1) megascopic microbially produced stromatolites; (2) microscopic cellularly preserved microorganisms; and (3) particulate carbonaceous matter (kerogen), identifiable on the basis of its carbon isotopic composition as a product of biological activity.
The discovery of these Archean fossils has created a problem for the paleontological community. Fossils of this age contradict models of the origin of life on this planet1(Schopf, 1999). Whatever the requirements that evolution might dictate, plant fossils clearly exist within these ancient rocks.
These fossils force uniformitarians to deal with the sudden appearance of life in Earths supposed very distant past. These plant fossils have been found in Precambrian rocks across the globe (Cooper, Jago, MacKinnon, Shergold, and Vidal, 1982; Glaessner, 1979; Hofmann and Schopf, 1983; Iltchenko, 1972). Within the evolutionary model this suggests that plant life was flourishing very early in Earths history, and that it must have evolved and expanded rapidly (Schopf, 1982, 1999). No credible explanation of these discoveries has been provided to explain the presence of these fossils through evolution and dispersion.
The organic remains of Precambrian plant fossils are found within ancient sedimentary and metasedimentary2 rocks and strata found on the continents. However, extracting the organic remains of these plant fossils remains a complicated and exacting science, and contamination is believed to be a serious problem (Schopf, 1999; Schopf and Walter, 1983).
Precambrian Plant Fossils and the Hakatai Shale
How do young-earth creationists explain the Precambrian strata that contain plant fossils? Unfortunately, not much has been written about these plant fossils by creationists. The Hakatai Shale, found within the Grand Canyon, has received the most intensive investigation to date. Several varieties of plant fossils have been identified and reported within the Hakatai Shale (Burdick, 1966, 1972, 1974a); however, challenges have been raised causing some to question their relevance within a biblical framework (Rusch, 1968, 1982). Further confusion has resulted from some creationists incorporating a compressed version of the global uniformitarian column in their creationist model3 (Austin, 1994; Austin and Wise, 1994, and in preparation; Baumgardner, 1990; Snelling, Scheven, Garner, Ernst, Austin, Garton, Scheven, Wise, and Tyler, 1996). One creation scientist has proposed that Precambrian plant fossils might have been created during the creation week to fit them within his model (Wise, 1992). Counter to this uniformitarian-column-based approach, other young-earth creationists have proposed that Precambrian strata containing plant fossils formed during the global Flood, and have no link to the uniformitarian stratigraphic column (Froede, Howe, Reed, and Meyer, 1998; Hunter, 1992; Snelling, 1991; Woodmorappe, 1983).
The most interesting and controversial creationist Precambrian plant fossil study was conducted by Clifford Burdick (Burdick, 1966, 1972, 1974a). He examined the Hakatai Shale strata within the Grand Canyon and reported finding a wide variety of pollen and spores. Following this study, other scientists confirmed Burdicks work (Chadwick, DeBord, and Fisk, 1973). In a later effort to buttress his position, Burdick documented other areas across the planet where Precambrian and Cambrian pollen were reported (Burdick 1974b, 1975, 1982). A subsequent investigation of the Hakatai Shale (Chadwick, 1982), however, found no evidence of any plant fossils, and proposed that contamination was the cause of the earlier findings of pollen and spores. This raised doubts about Burdicks work.
The controversy surrounding Burdicks work centered around his finding both modern and ancient fossilized forms of plant spores and pollen in the Hakatai Shale. Evolutionists would not have had any problems with Burdicks work if only ancient fossilized forms were found. Finding modern forms of spores and pollens created a serious age issue with this shale layer. In the creationist community Burdicks work creates controversy for those who define the Flood/pre-Flood boundary as the contact between the Precambrian and Cambrian. They should not find plant fossils in rocks which they define as having formed early in the Creation Week (before plants were created). For both these groups Burdicks findings created different problems for different reasons.
To resolve this lingering controversy over the presence or absence of pollen grains and spores within the Hakatai Shale, members of the Creation Research Society (CRS) collected and analyzed their own samples in an effort to confirm or refute Burdicks earlier findings (Howe, 1986; Howe, Williams, Matzko, and Lammerts, 1986, 1988; Lammerts and Howe, 1987). Their results supported Burdicks findings of modern spores and pollen within the Hakatai Shale. Of course this confirmation remains counter to the evolutionary model (Chaloner, 1967; Cloud, 1968), and is very controversial. The uniformitarian model does not predict or allow for the presence of modern pollen and spores within the Hakatai Shale as it is too old to contain these advanced types of plant fossils. The incorrect sequence contradicts the global uniformitarian column, which may explain why certain creationists remain skeptical of the conclusions of this latest confirmatory study. For whatever reason, some creationists have also rejected the possibility of modern or ancient pollen, spore, or any other plant material within the Hakatai Shale (Austin, 1994, pp. 63, 137; Austin and Wise, 1994, pp. 3839).
Recently, questions were raised regarding the validity and methodology of the CRS confirmation study from an Internet post forwarded to the Quarterly Editor. Answers to the posts issues were provided explaining why earlier studies failed to identify the modern and/or ancient plant pollen and spores within the Hakatai Shale (Williams, 1997). The results of this latest study supports the belief that pollen and spores occur within the Hakatai Shale and that they were deposited contemporaneously with the strata.
Hakatai Shale Comparisons with Other Fossiliferous Precambrian Strata
Uniformitarians view the Hakatai Shale as being deposited during the Proterozoic. It is age dated at approximately 1.25 Ga. Comparison of this Precambrian section to those of similar age found across other sections of the globe suggests that it is not out of the question to expect or find fossilized plant materials within the Hakatai Shale (Figure 2). Modern pollen and spores, however, are not expected in strata of this extreme age. In fact it is somewhat surprising that ancient fossilized plant material has not been identified at an earlier date by uniformitarians for this stratigraphic unit (although it should be noted that Elston [1989, p. 264] hinted at the possibility of stromatolites being present within the Hakatai Shale, and Horodyski [in Link et al., 1993, p. 561] referenced a wide variety of fossils within various Precambrian strata of the Grand Canyon). However, the confirmation of ancient fossilized plant material per se in the Hakatai Shale would not contradict the uniformitarian model, as far older Precambrian strata have been found to contain plant fossils (Figure 2).
Implications For the Young-Earth Flood Model
The Precambrian Hakatai Shale has been examined four times for the presence of plant fossils. Ancient and modern forms were found in three of those investigations. However, some creationists still reject the presence of any fossilized plant material within the Hakatai Shale as it disagrees with their model (see Austin, 1994, p. 58, Figure 4.1; Austin and Wise, 1994, p. 40, Figure 1). According to Austin and Wise, the majority of the Precambrian strata represent Creation Week deposits and should not contain plant fossils since they formed before plants were created. They suggest that plant fossils would only occur in abundance within Flood deposits (i.e., above their Precambrian / Cambrianpre-Flood / Flood boundary). By implication their model would need to explain the evidence of plant fossils within Precambrian strata from areas both in and outside of the Grand Canyon (see Appendix). This point is important because Austin and Wise have stated that they support the general framework of the global uniformitarian timescale while denying the old age of the earth (Austin 1994, p. 58, Figure 4.1; Austin and Wise, 1994, p. 40, Figure 1; Snelling et al., 1996). In order to defend their pre-Flood/Flood boundary being globally chronostratigraphically equivalent to that of the Precambrian/Cambrian boundary they should undertake palynological studies to prove that fossilized plants do not exist within any Precambrian strata. Their model of the stratigraphic column in the Grand Canyon remains questionable if they continue to deny the presence of Precambrian plant fossils.
The identification of plant fossils within Precambrian shales has been documented. In fact, several uniformitarian geologists have commented that:
...in the light of results summarized here [for the Grand Canyon] together with important discoveries recently reported from other Precambrian shales, it seems reasonable to conclude that shaley facies represent a promising, but as yet largely untapped, source of new evidence on the diversity, evolution, and biostratigraphic usefulness of the Precambrian biota (Bloeser, Schopf, Horodyski, and Breed, 1977, p. 679).
I urge creationists to undertake studies to find fossilized plant materials in all Precambrian strata in an effort to help delineate the impact which the Flood had on the Earths stratigraphic record.
A variety of Precambrian plant fossils have been documented in rocks as ancient as the Archean (Figure 2). Presently, any specifics about the kind of plants from which these fossilized remains were derived cannot be ascertained. Each new discovery of ancient fossilized plant material pushes back the timing of evolution of life on this planet. This creates difficulties for evolutionary models of lifes origin and early history. Young-earth creationists hopefully will keep abreast of this interesting and relevant work. In addition to highlighting weaknesses in the evolutionary model, it helps us to define and refine our own framework of Flood-dominated stratigraphy.
It is important to note that proving the existence of generic plant material in the Hakatai Shale within the Grand Canyon will not affect the uniformitarian model of Earth history; it would only add a new location where Proterozoic plant material has been found. It is the evolutionary stage of Burdicks discovery that contradicts the global uniformitarian column. With time new older Archean outcrops containing plant fossils may be found. The problem which uniformitarian geologists and paleontologists must address remains that of explaining lifes point of origin and rapid dispersion across the planet.
The Austin/Wise stratigraphic model for the Grand Canyon appears questionable as is denies the known presence of Precambrian plant life found both within the canyon and globally. Further clarification is required in order to reconcile these conflicts in their model. The presence of plant fossils within the Hakatai Shale, documented on three occasions, also casts doubt on their approach to defining the strata within the Grand Canyon. Hopefully these issues will be addressed in the near future.
Young-earth creationists should consider the paleontological potential of all sedimentary and metasedimentary Precambrian strata. Finding fossilized plant life within these ancient rock layers might be expected within the young-earth Flood model. Several creationists have proposed that some Precambrian strata were deposited during the global Flood of Genesis (Figure 3).
Creationists should take an active part in paleontological studies locating ancient Precambrian fossils across the earth. By doing so we accomplish two objectives: 1) We extend the depth of strata likely affected by the Flood, and 2) we push evolutionists to explain how life arose fully-formed across the earth so rapidly, and so very long ago. We need to aggressively pursue paleontological studies if we wish to demonstrate the weaknesses of evolution and uniformitarian geology in explaining the stratigraphic record. This is what the global uniformitarian stratigraphic column is based on (evolutionary biology/paleontology and not radiometric dating!) and this is where we need to focus our efforts (Froede, 1994, 1997). Precambrian plant fossils provide excellent evidence of Flood deposition within the young-earth Flood model.
The controversy over the paleontology and stratigraphy of the Hakatai Shale (or any other Precambrian strata) raises a larger question than the mere presence or absence of fossilized plant material in the Precambrian. Rather, the core issue is whether or not young-earth creationists should use the global uniformitarian column to define biblical history. Austin and Wise follow the general framework of the global uniformitarian column (Austin, 1994, p. 58, Figure 4.1; Austin and Wise, 1994, p. 40, Figure 1; Snelling et al., 1996, p. 333, Figure 1). They have also proposed that the pre-Flood/Flood boundary should occur at the uniformitarian Precambrian/Cambrian boundary (Figure 2). This is based on their definition of the Paleontological Discontinuity criteria:
The slow deposition in the pre-Flood world would have made fossilization of plant, animal and fungal remains unlikely. Also, it is very likely that the initial erosion of the Flood destroyed or reworked virtually all of the fossils which were present in pre-Flood sediments. Consequently, below the pre-Flood/Flood boundary, sediments capable of preserving fossils might, at best, contain only traces of the most abundant and easily fossilized life formsbacterial, algal, and protist fossilsand probably in very low abundance. Plant, animal and fungal fossils might be expected to be found in high abundance only above the pre-Flood/Flood boundary.(Austin and Wise, 1994, p. 40) (Italics mine)
This statement is inconsistent, however, when dealing with the evidence of plant fossils in the uniformitarian Precambrian strata, and runs counter to what Schopf (1994, p. 194) has stated about the presence of plant fossils found within the Precambrian, Proterozoic Eon:
Stromatolites are virtually ubiquitous in Proterozoic carbonate terranes, represented by hundreds of taxonomic occurrences reported from a large number of Proterozoic basins. ...literally hundreds of microfossiliferous formations and nearly 3,000 occurrences of bona fide microfossils have been discovered in Proterozoic-age strata...
These creationists appear to have overlooked the record of plant fossils taken directly from the Precambrian strata within the Grand Canyon! They do not believe that plant fossils are abundant within the Precambrian strata of the Grand Canyon, and yet uniformitarians have documented them in several places and in abundance (see Bloeser, Schopf, Horodyski, and Breed, 1977; Elston, 1989; Elston and McKee, 1982; Ford, 1990; Horodyski, 1993; Knauth, 1994; Link et al., 1993; Nations and Stump, 1996; Schopf, Ford, and Breed, 1973). Since the Austin/Wise stratigraphic model for the Grand Canyon is inconsistent with the physical evidence, perhaps they should reexamine the role of the global uniformitarian column in their model. The global uniformitarian stratigraphic column is not required within the young-earth Flood model (Froede and Reed, 1999). I recommend that the use of the global uniformitarian column to define Flood geology in the Grand Canyon (or anywhere else) be rejected.
I thank Dr. George F. Howe and Dr. Emmett L. Williams for sharing their experiences with me regarding the controversy surrounding the presence of pollen and spore material within the Hakatai Shale. Both gentlemen kindly provided me with review and comment on various drafts of this document. Additionally, all of the peer-review comments were of great help to me in further clarifying this article. However, any mistakes which remain are my own. I thank my wife for allowing me the time to write for the Creation Research Society Quarterly. Glory to God in the highest (Pr 3:5-6).
CRSQ: Creation Research Society Quarterly
CENTJ: Creation Ex Nihilo Technical Journal
Austin, S.A. (editor). 1994. Grand Canyon: Monument to catastrophe. Institute for Creation Research, Santee, CA.
Austin, S. A. and K.P. Wise. 1994. The Pre-Flood/Flood boundary: As defined in Grand Canyon, Arizona and eastern Mojave Desert, California. In Walsh, R.E. (editor). Technical symposium sessions. Proceedings of the Third International Conference on Creationism. Creation Science Fellowship, Pittsburgh, PA. pp. 3747.
. In preparation. Defining the pre-Flood/Flood boundary within strata of the Southwestern United States. ICR Technical Monograph. Institute for Creation Research, Santee, CA.
Baumgardner, J. R. 1990. The imperative of non-stationary natural law in relation to Noahs Flood. CRSQ 27:98100.
Bloeser, B., J. W. Schopf, R. J. Horodyski, and W. J. Breed. 1977. Chitinozoans from the Late Precambrian Chuar Group of the Grand Canyon, Arizona. Science 195:676679.
Burdick, C . L. 1966. Microflora of the Grand Canyon. CRSQ 3:3850.
. 1972. Progress report on Grand Canyon palynology. CRSQ 9:2530.
. 1974a. Canyon of canyons. Bible-Science Association, Caldwell, Idaho.
. 1974b. More Precambrian pollen. CRSQ 11:122123, 126.
. 1975. Cambrian and other pollen in the literature. CRSQ 12:175177.
. 1982. Reply to Rusch. CRSQ 19:144.
Chadwick, A.V. 1982. Precambrian pollen in the Grand Canyon; A reexamination. Origins 8:712.
Chadwick, A. V., P. DeBord, and H. Fisk. 1973. Grand Canyon palynology A reply. CRSQ 9:238.
Chaloner, W. G. 1967. Spores and land-plant evolution. Review of Palaeobotany and Palynology 1:8393.
Cloud, P. 1968. Pre-metazoan evolution and the origins of the metazoa. In Evolution and environment. Yale University Press, New Haven, CT. pp. 172.
. 1976. Beginnings of biospheric evolution and their biogeochemical consequences. Paleobiology 2:351387.
. 1983. Aspects of Proterozoic biogeology. In Medaris, L. G., Jr., C. W. Byers, D. M. Mickelson, W. C. Shanks (editors). Proterozoic geology: Selected papers from an international Proterozoic symposium. Geological Society of America Memoir 161. Boulder, CO. pp. 245251.
Cooper, R. A., J. B. Jago, D. I. MacKinnon, J. H. Shergold, and G. Vidal. 1982. Late Precambrian and Cambrian fossils from northern Victoria Land and their stratigraphic implications. In Craddock, C. (editor). Antarctic geoscience. International Union of Geol. Sciences. Univ. of Wisconsin Press, Madison. pp. 629633.
Elston, D. P. 1989. Grand Canyon Supergroup, northern Arizona: Stratigraphic summary and preliminary paleomagnetic correlations with parts of other North American Proterozoic successions. In Jenney, J. P. and S. J. Reynolds (editors). Geologic evolution of Arizona. Arizona Geological Society, Tucson, AZ. pp. 259272.
Elston, D. P. and E. H. McKee. 1982. Age and correlation of the late Proterozoic Grand Canyon disturbance, northern Arizona. Geological Society of America Bulletin 93:681699.
Ford, T. D. 1990. Grand Canyon Supergroup: Nankoweap Formation, Chuar Group, and the Sixtymile Formation. In Beus, S. S. and M. Morales (editors). Grand Canyon geology. Oxford University Press, New York. pp. 4970.
Froede, C. R., Jr. 1994. Fossil wood of Big Bend National Park. CRSQ 30:187189.
. 1995. A proposal for a creationist geological timescale. CRSQ 32:9094.
. 1997. The global stratigraphic record. CENTJ 11(1):4043.
. 1998. Field studies in catastrophic geology. Creation Research Society Books, St. Joseph, Mo.
Froede, C. R., Jr., G. F. Howe, J. K. Reed, and J. R. Meyer. 1998. A preliminary report on the Precambrian Pikes Peak Iron Formation, Yavapai County, Arizona. CRSQ 35:1522.
Froede, C. R., Jr. and J. K. Reed. 1999. Assessing creationist stratigraphy with field evidence. CRSQ : 36:5160.
Glaessner, M. F. 1979. Precambrian. In Robison, R. A. and C. Teichert (editors). Treatise on invertebrate paleontology, Part A: Introduction. Geological Society of America, Boulder, CO. pp. A79A118.
Harrison, J. E. and Z. E. Peterman. 1982. Precambrian time scale. In Dutro, J. T., Jr., R. V. Dietrich, and R. M. Foose (compilers). 1989. American Geological Institute data sheets. Third edition. Alexandria, VA. p. 1.3
Hofmann, H. J. 1971. Precambrian fossils, pseudofossils, and problematica in Canada. Geological Survey of Canada Bulletin 189. Ottawa.
Hofmann, H. J. and J. W. Schopf. 1983. Early Proterozoic microfossils. In Schopf, J. W. (editor). Earths earliest biosphere: Its origin and evolution. Princeton University Press, Princeton, NJ. pp. 321360.
Horodyski, R. J. 1993. Paleontology of Proterozoic shales and mudstones: Examples from the Belt Supergroup, Chuar Group and Pahrump Group, western USA. Precambrian Research 61:241278.
Howe, G. F. 1986. Creation Research Society studies on Precambrian pollen. CRSQ 23:99104.
Howe, G. F., E. L. Williams, G. T. Matzko, and W. E. Lammerts. 1986. Pollen research update. CRSQ 22:181182.
. 1988. Creation Research Society studies on Precambrian pollenPart III: A pollen analysis of Hakatai Shale and other Grand Canyon rocks. CRSQ 24:173182.
Hunter, M. J. 1992. Archean rock strata: Flood deposits the first 40 days. In Proceedings of the 1992 Twin-cities Creation Conference. Twin-Cities Creation-Science Association. Northwestern College, Roseville, MN. pp. 153161.
Iltchenko, L. N. 1972. Late Precambrian acritarchs of Antarctica. In Adie, R. J. (editor). Antarctic geology and geophysics. International Union of Geological Sciences. Scandinavian University Books, Oslo, Norway. pp. 599602.
Knauth, L. P. 1994. Life on land in the PrecambrianThe Arizona connection. In Boaz, D., M. Dornan, and S. Bolander (editors). Fossils of Arizona Symposium. Mesa Southwest Museum, Mesa, AZ. pp. 2332.
Knoll, A. H. 1992. Biological and biogeochemical preludes to the Ediacaran radiation. In Lipps, J. H. and P. W. Signor (editors). Origin and early evolution of the metazoa. Plenum Press, New York. pp. 5384.
Lammerts, W. E. and G. F. Howe. 1987. Creation Research Society studies on Precambrian pollenPart II: Experiments on atmospheric pollen contamination of microscope slides. CRSQ 23:151153.
Link, P. K., N. Christie-Blick, W. J. Devlin, D. P. Elston, R. J. Horodyski, M. Levy, J. M. G. Miller, R. C. Pearson, A. Prave, J. H. Stewart, D. Winston, L. A. Wright, and C. T. Wrucke. 1993. Middle and Late Proterozoic stratified rocks of the western U.S. cordillera, Colorado plateau, and basin and range province. In Reed, J. C., Jr., M. E. Houston, R. S. Houston, P. K. Link, D. W. Rankin, P. K. Sims, and W. R. Van Schmus (editors). Precambrian: Conterminous U. S. The geology of North America, Vol. C-2. Geological Society of America, Boulder, CO. pp. 558565.
Margulis, L. 1988. The ancient microcosm of planet earth. In Osterbrock, D. E. and P. H. Raven (editors). Origins and extinctions. Yale University Press, New Haven, CT. pp. 83107.
McMenamin, M. A. S. and D. L. S. McMenamin. 1990. The emergence of animals: The Cambrian breakthrough. Columbia University Press, New York.
McNamara, K. and J. Long. 1998. The evolution revolution. Wiley Press. New York.
Nations, D. and E. Stump. 1996. Geology of Arizona. Second edition. Kendall/Hunt, Dubuque, IA.
Read, H. H. and J. Watson. 1975. Introduction to geology, Volume 2: Earth history, Part I: Early stages of Earth history. John Wiley and Sons, New York.
Reed, J. K. and C. R. Froede Jr. 1997. A biblical Christian framework for Earth history research Part IIIConstraining geologic models. CRSQ 33:285292.
Reed, J. K., C. R. Froede Jr., and C.B. Bennett. 1996. The role of geologic energy in interpreting the stratigraphic record. CRSQ 33:97101.
Rusch, W. H., Sr. 1968. The revelation of palynology. CRSQ 5:103105.
. 1982. The present position of Pre-Cambrian pollen. CRSQ 19:143144.
Schopf, J. W. 1982. The evolution of the earliest cells. In The fossil record and evolution: Readings from Scientific American. W. H. Freeman, San Francisco, CA. pp. 4662.
. 1994. The oldest known records of life: Early Archean stromatolites, microfossils, and organic matter. In Bengtson, S. (editor). Early life on earth. Columbia University Press, New York. pp. 193206.
. 1999. Cradle of life: The discovery of earths earliest fossils. Princeton University Press, Princeton, NJ.
Schopf, J. W., T. D. Ford, and W. J. Breed. 1973. Microorganisms from the Late Precambrian of the Grand Canyon, Arizona. Science 179:13191321.
Schopf, J. W. and M. R. Walter. 1983. Archean microfossils: New evidence of ancient microbes. In Schopf, J. W. (editor). Earths earliest biosphere: Its origin and evolution. Princeton University Press, Princeton, NJ. pp. 214239.
Snelling, A. A. 1991. Creationist geology: Where do the Precambrian strata fit? CENTJ 5:154175.
Snelling, A. A., J. Scheven, P. Garner, M. Ernst, S. A. Austin, M. Garton, E. Scheven, K. P. Wise, and D. Tyler. 1996. The geological record. CENTJ (3):333334.
Strother, P. K. 1989. Pre-metazoan life. In Allen, K. and D. Briggs (editors). Evolution and the fossil record. Smithsonian Institution Press, Washington, D.C. pp. 5172.
Walker, T. 1994. A biblical geologic model. In Walsh, R.E. (editor). Technical symposium sessions. Proceedings of the Third International Conference on Creationism. Creation Science Fellowship, Pittsburgh, PA. pp. 581592.
Walter, M. R.. 1983. Archean stromatolites: Evidence of the Earths earliest benthos. In Schopf, J. W. (editor). Earths earliest biosphere: Its origin and evolution. Princeton University Press, Princeton, NJ. pp. 187213.
Williams, E. L. 1997. Precambrian pollenA response. CRSQ 33:239242.
Wise, K. W. 1992. Some thoughts on the Precambrian fossil record. CENTJ 6:6771.
Woodmorappe, J. 1983. A diluvial treatise on the stratigraphic separation of fossils. CRSQ 20:133185.