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According to mineralogical literature, some of the finest opalized wood in the world was discovered in Idaho c.1895, originating in a unique deposit along Clover Creek in Lincoln County (now Gooding County). The American mineral dealer Dr A. E. Foote acquired and processed the bulk of the discovery into specimens that were advertised between 1896 and 1904. Over a period of four years, we have identified sixteen natural history museums in Europe, North America, and Australia in possession of Clover Creek opalized oak today. Many museum acquisitions and the fossil’s taxonomic affinity, Quercinium pliocaenicum, resulted from collective networking between mineral dealers, private collectors and scientists – evidence of a common interest among a diversity of people – contributing the best specimens for museums of natural history.

Central Wyoming, USA, was the site of ancient Lake Gosiute during the Early Eocene. Lake Gosiute was a large body of water surrounded by subtropical forest, the lake being part of a lacustrine complex that occupied the Green River Basin. Lake level rises episodically drowned the adjacent forests, causing standing trees and fallen branches to become growth sites for algae and cyanobacteria, which encased submerged wood with thick calcareous stromatolitic coatings. The subsequent regression resulted in a desiccation of the wood, causing volume reduction, radial fractures, and localized decay. The subsequent burial of the wood in silty sediment led to a silicification of the cellular tissue. Later, chalcedony was deposited in larger spaces, as well as in the interstitial areas of the calcareous coatings. The final stage of mineralization was the precipitation of crystalline calcite in spaces that had previously remained unmineralized. The result of this multi-stage mineralization is fossil wood with striking beauty and a complex geologic origin.

Fascination with petrified wood has stimulated interest in understanding the process of natural petrifaction. Early attempts of modeling natural petrifaction in the laboratory have been limited to mimicking incipient permineralization resulting in the creation of silica casts of pore spaces and inner cell walls. Silica lithomorphs produced through artificial silicification provided a possible avenue for studying microstructure of wood. More recently artificial petrifaction is motivated by the goal of creating advanced ceramic materials for engineering applications. The concept of using wood as a biotemplate has led to the creation of porous ceramics by cell wall replacement. To some extent artificial and natural petrifaction processes are comparable; although, some of the materials and procedures used in the laboratory are not found in nature. Research focused on the composition and structure of fossil wood from different-aged deposits is compared with research focused on the development of wood-templated porous ceramics. Differences and similarities in the pathways of natural silicification and creation of biomorphous ceramics are discussed. The comparison between artificial and natural silicification highlights the particular significance of the degree to which (de)lignification is needed for silica permeation.

The Bruneau Woodpile site has long been popular among fossil collectors; however, the deposit has received scant attention from scientists. Our research reveals that the fossilized wood was deposited ca. 6.85 Ma, within the Chalk Hills Formation, and was mineralized with carbonate-fluorapatite. The diverse assemblage of conifers and hardwoods is representative of the warm temperate forests that flourished in southwest Idaho, USA during the late Miocene. Limb and trunk fragments preserved in a single thin sandstone bed appear to represent woody debris that was transported by streams. One possible explanation is that wood, pumice, and sandy volcaniclastic sediment arrived separately as a result of ordinary stream action, and later were combined into a single assemblage during a subsequent high-energy sedimentation event. We favor an alternate hypothesis: a catastrophic event (e.g., a windstorm) damaged trees on slopes bordering the ancient lake. Branches and small trunk fragments were carried by wind and rain into local streams and ponds where they became waterlogged. After a delay that allowed pumice and wood to become saturated, storm water transported these materials, along with finer volcaniclastic sediment, into a lake. The resulting density current produced a fining-upward sedimentary cycle where wood was preserved in the lowest, coarsest stratum.

An extensive fossil forest discovered in 2010 on private property in central Colorado, USA, has not previously been described in scientific literature. Horizontal partial logs originated as fluvially transported driftwood. A preliminary study of petrified wood specimens reveals evidence of a complex mineralization sequence that involved multiple episodes of mineral deposition, combined with diagenetic transformation of silica minerals. Specimens from two logs have opalized cell walls. However, minerals filling the cell interiors of these specimens vary. Vessel lumina are filled with chalcedony or crystalline quartz; tracheid lumina may contain opal or chalcedony. Specimens from 5 other logs contain quartz/chalcedony, but relict textures suggest cell walls were originally mineralized with opal that was later converted to microcrystalline silica. Pyrite, calcite, and iron oxides were observed as minor constituents in some specimens, providing additional evidence that fossilization occurred in multiple stages, with temporal and spatial variations in physical and chemical conditions causing episodic precipitation of various minerals within the buried wood. Trace element analyses suggest that Fe is the main source of fossil wood color.

The1930 discovery of Carboniferous lycopsid fossils in south central Colorado resulted in the naming of a new species of scale tree, Lepidodendron johnsonii (=Lepidopholios johnsonii (Arnold) DiMichelle). Cellular structuresof L. johnsonii axes and periderm are preserved in silica&mdash, an unusual mode of fossil preservation for Pennslyvanian lycopsid plant remains. The early reports on the Trout Creek lycopsid fossils focused on taxonomic and paleobotanical aspects. Our 2019 reinvestigation of the locality produced many new specimens and a wealth of new data from a variety of analytical methods. Optical microscopy, X-ray diffraction, scanning electron microscopy, energy dispersive electron spectroscopy, determination of specific gravity, and Loss on Ignition provide details of mineralization. Cell walls are preserved with very small fine quartz particles, and cell lumina are filled with microcrystalline quartz. Some cell exteriors are encrusted with euhedral quartz crystals. These multiple forms of quartz are evidence that petrifaction involved several episodes of silicification. The dark color of the fossil wood and siliceous matrix appears to be caused by traces of dispersed carbon, but 500 &deg, C Loss on Ignition reveals that the fossil wood preserves only very small amounts of the original organic matter.

The 1895 discovery of a petrified tree near Clover Creek in south-central Idaho, USA, attracted worldwide attention and resulted in the naming of a new species of ancient oak, Quercinium pliocaenicum Schuster. For more than a century, the discovery has largely been forgotten, even though specimens reside in reputable museums. Reinvestigation of the locality in 2014/2015 resulted in newly-collected specimens and a wealth of new data. Optical microscopy confirms the cellular anatomy used for the original taxonomic study. X-ray diffraction, scanning electron microscopy, energy-dispersive electron spectroscopy, Raman spectroscopy and cathodoluminescence microscopy reveal details of the mineralization, showing the presence of opal-CT as the primary component, with chalcedony as a lesser constituent. This mineralogy suggests petrifaction occurred in at least two stages, beginning with opalization of cellular tissue, leaving open vessels that became filled with chalcedony during a later mineralization episode. Clover Creek oak represents relict flora growing in a wetter climate before the uplift of the Cascade Range created a rain shadow that caused profound desertification of the inland Pacific Northwest.

Efforts by state and local officials to enact balanced treatment laws represent attempts to displace the methodological naturalism of science with theological supernaturalism. Advocates of creation science and intelligent design (ID) also seek to wedge the supernatural into scientific explanations. Robert Pennock (2000) distills the controversy to its core features when he states, "debate [is] about truth itself and how we come to know it" (p. 40). In this article I assume methodological naturalism as a presupposition in modern science. This is in agreement with the decision handed down by Judge John E. Jones III in the Dover, Pennsylvania ID case. Citing trial testimony from well-known philosophers of science, Jones (2005) wrote, "Methodological naturalism is a 'ground rule' of science today which requires scientists to seek explanations in the world around us based upon what we can observe, test, replicate, and verify" (p. 65). Legal challenges to the teaching of evolution as a process explicable by naturalistic causes or to exclusive reliance on naturalism in science would alter science education by redefining science. Langdon Gilkey (1985) notes that these challenges pose additional threats. First, such laws would establish a particular form of Christian religion in the science classroom. This threatens free religious life in our society as well as freedom from religion. Second, such laws attack academic freedom. States often legislate what subjects are to be taught in the curriculum, but they should not dictate which theories are to be taught within these mandated subjects (pp. 13-14). Attacks on the nature of science should motivate us to teach not only that science adds to our body of knowledge but also to emphasize how it does this. In what follows, I set forth an interactive activity titled "Epistemology and the Nature of Science" designed for this purpose. Epistemology is the formal study of the nature and limits of human knowledge. It includes careful assessments of the limitations of the methods we employ when we make claims about what it is we know. The interactive activity helps students realize that the body of knowledge we associate with science is established using specific epistemic methods. I begin with a brief description of the format of the activity, which involves constructivist listening and the dyad. Following this, in Part I, I canvas how student responses reflect and fail to reflect major ways of knowing and their relation to science. In Part II, I use Judge William Overton's list of the characteristics of science--from the 1982 Arkansas creation trial--to focus discussion specifically on the nature of science. Constructivist Listening & the Dyad I developed Epistemology and the Nature of Science as an interactive activity for use with my Grade 9 students six years ago. Currently, I use it for my Grade 8 Pre-AP Introduction to Chemistry, Physics, and Earth Sciences course and my Grade 9 Pre-AP Biology and regular Biology classes. I have also used it with adults who teach science and math for Grades 5-12 for professional development. Central to this activity are the concepts of constructivist listening and the dyad. Constructivist listening is a process that allows one to talk without being interrupted and thereby to explore thoughts in an unimpeded manner. Talking can be as important to the learning process as listening. This is evident when teachers use questioning strategies that encourage students to talk through solutions for particular problems. Teachers often say they didn't really learn a subject in depth until they had to teach others. This may be due, in part, to the fact that teachers must talk about their subject areas. Constructivist listening is not a conversation or dialogue. Listening is really for the benefit of the speaker. It allows the speaker to explore content or feelings without being interrupted. The dyad is one structure that promotes constructivist listening. …