Organic geochemistry of funginite (Miocene, Eel River, Mendocino County, California, USA) and macrinite (Cretaceous, Inner Mongolia, China)

Accepted Manuscript Organic geochemistry of funginite (Miocene, Eel River, Mendocino County, California, USA) and macrinite (Cretaceous, Inner Mongolia, China)

Shifeng Dai, Russell Bartley, Sylvia Bartley, Bruno Valentim, Alexandra Guedes, Jennifer M.K. O'Keefe, Jolanta Kus, Maria Mastalerz, James C. Hower PII: DOI: Reference:

S0166-5162(17)30179-9 doi: 10.1016/j.coal.2017.05.015 COGEL 2842

To appear in:

International Journal of Coal Geology

Received date: Revised date: Accepted date:

2 March 2017 17 May 2017 22 May 2017

Please cite this article as: Shifeng Dai, Russell Bartley, Sylvia Bartley, Bruno Valentim, Alexandra Guedes, Jennifer M.K. O'Keefe, Jolanta Kus, Maria Mastalerz, James C. Hower , Organic geochemistry of funginite (Miocene, Eel River, Mendocino County, California, USA) and macrinite (Cretaceous, Inner Mongolia, China). The address for the corresponding author was captured as affiliation for all authors. Please check if appropriate. Cogel(2017), doi: 10.1016/j.coal.2017.05.015

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ACCEPTED MANUSCRIPT Organic geochemistry of Funginite (Miocene, Eel River, Mendocino County, California, USA) and Macrinite (Cretaceous, Inner Mongolia, China)

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Shifeng Dai a , Russell Bartley b, Sylvia Bartley c, Bruno Valentim d, Alexandra Guedes d , Jennifer M.K. O’Keefe e , Jolanta Kus f, Maria Mastalerz g, James C. Hower h*

School of Resources and Geosciences, China University of Mining and Technology, Xuzhou 221116, China and State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing), Beijing 100083, China ([email protected])

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a

Mendocino County Museum, 400 East Commercial Street, Willits, CA 95490, USA Noyo Hill House, 28953 Highway 20, Fort Bragg, CA 95437 USA .

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c

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b

Instituto de Ciências da Terra (ICT), Pólo da Faculdade de Ciências da Universidade do Porto and Departamento de Geociências, Ambiente e Ordenamento do Território, Faculdade de Ciências, Universidade do Porto, Porto, Portugal

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Department of Earth and Space Sciences, 404-A Lappin Hall, Morehead State University, Morehead, KY 40351, USA

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e

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Federal Institute for Geosciences and Natural Resources, Department Geochemistry of Petroleum and Coal, Stilleweg 2, D-30655 Hannover, Germany f

Indiana University, Indiana Geological Survey, 611 N. Walnut Grove Ave., Bloomington, IN 47405-2208, USA g

University of Kentucky, Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511, USA (1-859-257-0261) h

* Corresponding author. Tel.:1-859-257-0261 E Mail: [email protected] (James C. Hower)

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ABSTRACT Funginite from the Miocene Sand Bank coal from outcrops along the Middle Fork Eel River in Mendocino County, California, and coprolitic macrinite from the Lower Cretaceous Shengli Formation No. 6 coal, Inner Mongolia, were investigated

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using optical microscopy, confocal scanning laser microscopy (CLSM), scanning

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electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), Raman micro spectroscopy, and micro-Fourier transform infrared spectroscopy (FTIR). The

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examinations showed that the Sand Bank funginite has a higher reflectance than the surrounding vitrinite and that the Shengli macrinite has a 0.41-1.13% reflectance

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range, lower than the reflectance of the adjacent fusinite but higher than the 0.360.37% Rr of the vitrinite. CLSM revealed fine structure and morphology of

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multicellular fungal sclerotia with distinct smooth to granular margins, thick bands

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enveloping the entire fungal body, and thin- or thick hyphae and hyphae lumens. SEM-EDS indicated that the rootlet interior to the funginite contained Si, Al, S, and

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Ca; the funginite and macrinite contained S and Ca; and the surrounding matrix

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contained illite and, perhaps, the phosphates gorceixite-crandallite. The coprolitic macrinite contained quartz and clay. The funginite proved to be more aliphatic than

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the surrounding vitrinite. The coprolitic macrinite and the macrinite have shorter and more branched aliphatic chains than the associated vitrinite. The obtained results contribute to the assesmnt of funginite and macrinite in terms of morphology and maceral chemistry, indicating an interaction of plant hosts with mutualistic fungi and decomposers.

Keywords: Inertinite; SEM-EDS; Raman; FTIR; CLSM; Macerals

ACCEPTED MANUSCRIPT 1. Introduction Recent studies have shown that inertinite macerals can originate from a wide variety of sources (Hower et al., 2009, 2011, 2013a,b; O’Keefe et al., 2011a, 2013; Dai et al., 2012, 2015; Scott, 2015). While the origin of inertinite is conflated with paleofires by some authors (e.g. Petersen, 1998; Scott, 2010; Diessel, 2010; Scott et al.,

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2014; Glasspool et al., 2015), the inertinite category is fascinatingly complex

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[International Committee for Coal and Organic Petrology (ICCP), 2001] and the charcoal origin of fusinite, while valid in itself, is not the only source of inertinite

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(Moore et al., 1996; Hower et al., 2013a,b; O’Keefe et al., 2013; Dai et al., 2015). Macrinite, in particular, represents a wide spectrum of complex

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floral/faunal/fungal/bacterial origins, producing a continuum of maceral forms lumped together under one ill-fitting name. For example, the informally-named

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‘copromacrinite’ (Hower et al., 2011, 2013a; O’Keefe et al., 2013), refers to brightly-

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reflecting macerals produced through excretion processes from arthropods. In both origin and characteristics, this maceral form does not fit into any inertinite definition

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within the ICCP (2001) inertinite classification. Another problematic inertinite is the

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maceral “funginite,” which is not brightly reflecting in all cases and, as demonstrated below, is not chemically ‘inert’. Funginite and secretinite were split from the

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previously-used term sclerotinite (Lyons et al., 1986; Moore et al., 1996; Taylor and Taylor, 1997; Taylor et al., 1998; Lyons, 2000; ICCP, 2001) to reflect their very separate origins and morphology. Funginite represents body fossils (spores, hyphae, sclerotia, mycelia, etc.) of organisms generally belonging to the Fungi kingdom, and is distinct from the Plantae origin of the fusinite-semifusinite-secretinite +/- macrinite (in part) line of inertinite macerals.

ACCEPTED MANUSCRIPT More information than just petrography is needed to clarify the origin of the macrinite, funginite, and secretinite macerals. These macerals, while frequently observed, are usually not abundant in any one coal, which makes it difficult to concentrate them through typical means (Dyrkacz et al., 1981, 1984, 1992). New micro-techniques are being used to assess the composition, origin, and genesis in situ

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of individual macerals in standard petrography preparations (Morga, 2014; although

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funginite was confused with secretinite in that work). The combination of these new methods with petrographic observations provides a powerful tool. Here, funginite from

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the Miocene Sand Bank Coal from outcrops along the Middle Fork Eel River (MFER) in Mendocino County, California, USA (Bartley et al., 2010) and macrinite (the

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copromacrinite variety) from the Lower Cretaceous Shengli Formation No. 6 coal, Inner Mongolia, China (Dai et al., 2012, 2015) were investigated using optical microscopy,

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confocal scanning laser microscopy, SEM-EDS, Raman micro spectroscopy, and

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micro-FTIR.

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2. Methods

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The samples were selected from previous (Bartley et al., 2010; Dai et al., 2015) and ongoing studies of the Sand Bank (samples 8644, 8650, 8654) and She ngli

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(samples W6 8, W6 16, and W6 18). The selected coals provide excellent examples of funginite (Sand Bank) and coprolitic macrinite (Shengli). Detailed petrographic and palynologic investigations of the Sand Bank coal are in progress.

2.1. Optical microscopy Random reflectance values of vitrinite, funginite, macrinite, and other macerals were measured with a Leitz Compact system at the University of Kentucky Center for

ACCEPTED MANUSCRIPT Applied Energy Research (CAER) using a reflected light, oil immersion, 50x objective (500x combined magnification) and ca. 4 × 4 μm measuring spot. The incident light was not polarized and the measurements were taken without stage rotation. The reflected light, centered on a 546 nm with a grating monochrometer, was measured using a Hamatsu photomultiplier calibrated against a series of glass standards.

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Vitrinite particles selected for analysis were flat and inclusion- and crack-free within

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the area of measurement; however, similar selectivity in the case of the macrinite, for example, was not feasible as the grains had pores and inclusions. Nevertheless, we

flat as possible within the measurement area.

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did our best to insure that the particles measured were as uniform, inclusion free, and

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Coal rank is ideally determined using many individual readings from vitrinite, up to 50 in the CAER laboratory. Here, reflectance measurements were obtained for

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macrinite and funginite particles, and the vitrinite and other inertinite macerals

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immediately adjacent to these macerals. As such, the reflectance values represent a few isolated measurements which, while within the range of the overall spread of

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vitrinite measurements, are not individually representative of the overall coal rank.

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Also, since variable, but generally small numbers of readings were available for reflectances and for other quantitative techniques, the numbers should be seen as

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indicating general trends, and not ass statistically significant.

2.2. Confocal laser scanning microscopy The purpose of Confocal laser scanning microscopy (CLSM) is the investigation of the detailed microstructure, internal configuration and arrangement of cells

ACCEPTED MANUSCRIPT occurring in funginite and of the microstructure of macrinite. The information derived from CLSM allows morphological differentiation of macerals at µm and sub- µm level. Confocal laser scanning microscopy was conducted with a Leica TCS SP5 II Confocal Scanning System (CLSM) at the Federal Institute for Geosciences and Natural Resources, Hannover, Germany. The system is equipped with an inverted

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microscope DMI 6000 CS Bino fitted with a visual (VIS) Ar laser with laser lines at

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458, 476, 488, 496 and 514 nm; a DPSS laser with a laser line at 561 nm and a He/Ne laser with a laser line at 633 nm. An Acusto-Optical-Beam-Splitter (AOBS®)

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entirely replaced the conventional dichroic beam splitter. The confocal images were acquired in fluorescence mode through a HCX PLAPO oil-immersion objective (630x

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combined magnification, NA 1.4). The confocal scanning system was composed of free programmable scanners with frequency ranging from 1-1400 Hz and simultaneously

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the filter-free spectral detectors.

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operating on three spectral channels. Three photomultiplier tubes (PMT) comprise d

The auto fluorescence displayed in the CLSM images, projections and 3D

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reconstructions was generated by a selection of distinct laser lines from the Ar, DPSS,

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and He/Ne lasers and detected at specific emission wavelengths with the spectral imaging detector (SP). Three lasers lines of the Ar laser, with excitation at 458, 496

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and 633 nm, were used. The CLSM images displayed intensity values measured with the spectral detectors and represented 256 gray scale images. The gray scale images were converted to false color images by assigning different primary colors to each of the detector channels. The primary color assignment assured that the false color image corresponded to a very similar color range in a real color photomicrograph taken under an incident light microscope and displayed using an RGB (red/green/blue) color model. Assignments of blue (false color) to the first laser, green

ACCEPTED MANUSCRIPT to the second, and red to the third were made in order to match the color of the respective wavelengths of the light spectrum. The resulting pictures were each a composite of the three colors covering the emission range from 459 to 800 nm. Confocal images and 3D reconstructions were produced using Leica Application Suite Advanced Fluorescence (LAS AF SP5 3D Visualization) software version 2.4.1.

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During image acquisition in XY, XZ, YZ, and XYZ modes, each line was scanned in two

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directions 8x and images were captured as a series of 2D jpeg images with digital image resolution of up to 1024 × 1024 pixels. The consecutive confocal images

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obtained at increments of up to 0.25 μm were z-stacked as optical sections using the maximum projection method to obtain a composite 3D projection.

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The direct mode or reflecting mode in the CLSM method relies on reflection of the laser beam from the irradiated surface. The change in colors within images is a

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function of the height of the polished surface and the ability of the surface to reflect

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the laser beam. The brighter the color, (i) the more reflective the irradiated surface and (ii) the closer it is to the optical plane. The optical plane is parallel to the surface of the

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maceral and is the sole source of reflection of the laser beams. The optical plane is

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about 183.4 nm in height, i.e. voxel height. Indirectly, the colors in the images reflect

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the polishing hardness of funginite.

2.3. Scanning electron microscopy and energy-dispersive X-ray spectroscopy Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEMEDS) analysis was conducted at the Materials Center of the University of Porto, Portugal (CEMUP) using an FEI Quanta 400 FEG-ESEM/EDAX Genesis X4M instrument. The SEM was operated at 15 kV in high vacuum mode with manual aperture of 4.5. To improve analysis quality under high-vacuum conditions, all the

ACCEPTED MANUSCRIPT samples were sputter coated with carbon. Only the backscattered electron (BSE) detector mode was used, as the analysis was made with polished pellets. X-ray emission detected spectroscopy (EDS) was conducted to analyze the composition of the inorganic phases associated with the macrinite and funginite, including minerals and inorganic elements (e.g. Ca, S, P) which are within the organic matter structure.

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Sample 2654 was chemically etched to remove the masking effect of diagenesis

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and coalification on plant material in coal (Moore and Swanson, 1993) . This has the additional benefit of improving the ability to characterize macrinite and funginite

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structure using SEM. The etching procedure was according ASTM D5671 – 95 (2011), i.e. the polished block surface was submersed in KMnO 4 mixed with H2 SO4) for 15 s

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and rinsed with deionized water and a Na 2SO3 and H2SO4 rinsing solution.

2.4. Raman micro spectroscopy

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Raman micro spectroscopy has been used extensively to document the

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structural changes in natural carbon materials. Different authors have correlated the Raman spectrum and Raman parameters with changes in the structure of the

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materials; most of the studies have revealed that the first order and second order Raman spectra for organic matter in rocks differ with varying degree of coalification or

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graphitization (Beyssac et al., 2003; Bustin et al., 1995; Cuesta et al., 1994, 1998; Ferrari and Robertson, 2000, 2001; Green et al., 1983; Guedes et al., 2005, 2010; Jawhari et al., 1995; Rouzaud et al., 1983; Sadezky et al., 2005; Tuinstra and Koenig, 1970; Yoshida et al., 2006; Zerda et al., 2000). The technique allows a Raman spectrum with a lateral resolution of 1 μm to be obtained for a very small volume of material. Since it uses a microscope , it permits analysis of specific maceral components. Important research on the deconvolution of the Raman spectrum and the

ACCEPTED MANUSCRIPT assignments of the different Raman bands are described by Li et al. (2007) and Rebelo et al. (2016). The Raman measurements were completed on polished pellets prepared for organic petrography. Images of areas of interest were recorded at the CAER prior to shipping the pellets to the University of Porto. The spectra from funginite and

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macrinite and the surrounding material were initially obtained using a Horiba Jobin-

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Yvon LabRam Microscope XploRATM with a 100x objective lens, an excitation wavelength of 532 nm from a 25 mW Ar+ laser, and a range of diffraction gratings

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including 600, 1200, 1800, and 2400 lines/mm. Initial results displayed strong fluorescence emission, distorting the Raman spectra and causing consequent

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difficulties in structural quantification. We therefore, used a Raman LabRAM HORIBA Jobin Yvon Spex spectrometer interfaced to an Olympus microscope with 100x

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objective lens, diffraction gratings with 1800 lines/mm and equipped with a 20 mW

decomposition of samples.

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He/Ne laser with a 632.8 nm emission line. A density filter was used to avoid thermal

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The incident beam perpendicular to the plane of the sample was focused

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through the microscope lens, which also collected the back scattered Raman spectrum and transmitted it to a highly sensitive CCD camera. Extended scans were performed

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on the range 1000-1800 cm-1. The time of acquisition and the number of accumulations varied in order to provide an optimized spectrum for each maceral. The data were deconvoluted using a mixed Gaussian-Lorentzian curve-fitting procedure in a Labspec program from Horiba-Jobin Yvon. The curve-fitting methodology and assignment followed those described by Li et al. (2007) and Rebelo et al. (2016).

ACCEPTED MANUSCRIPT 2.5. Micro-FTIR Micro-FTIR measurements were completed at the Indiana Geological Survey using a Nicolet 6700 spectrometer connected to a Nicolet Continuum microscope operated in reflectance mode. The microscope was equipped with a video camera to display images and a computer-controlled mapping stage, and was linked to a liquid

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N2 cooled-mercury cadmium telluride (MCT) detector (Nicolet Instrumentations Inc.,

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Madison, WI, USA). The spectra were obtained at a resolution of 4 cm -1, using a gold plate as background. The OMNIC program was used for spectral deconvolution, curve

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fitting and determination of peak integration areas. Reflectance micro-FTIR spectra were subjected to Kramers-Kronig transformation. This transformation corrects for

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transflectance, shifts bands to the positions comparable with those in KBr pellet spectra (Kronig, 1926; Kramers, 1927), and needs to be used in reflectance micro-FTIR

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analysis on polished blocks of coal (Mastalerz and Bustin, 1996) . Peak assignments

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were based on Painter et al. (1981, 1985) and Wang and Griffiths (1985). Currently, the smallest aperture size use d for the analysis is 25×25 µm, because using a smaller

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aperture size results in spectra of poor quality due to deteriorating signal-to-noise

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ratio. The aperture size creates a challenge in the analysis of funginite as the cell walls are often < 25 µm. Further details about instrumentation and micro-FTIR

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mapping were presented by Chen et al. (2012, 2013).

3. Results and discussion 3.1 Maceral reflectance Random reflectance from the funginite and surrounding vitrinite was measured for the three Eel River samples and for the macrinite (frass), fusinite, semifusinite , and

ACCEPTED MANUSCRIPT vitrinite, as available, for the Shengli samples. For the Eel River coals, the funginite reflectance for samples 8644 and 8654 were in the 0.65-0.73%Rr range, with the adjacent vitrinite ranging from 0.46-0.54% Rr. Coal 8650 showed values of 0.540.59% Rr for funginite and 0.36-0.46% Rr for the adjacent vitrinite (Table 1). Not surprisingly, considering the complexity of its origin and diagenetic history

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(Dai et al., 2012, 2015), the Shengli macrinite exhibited a wide range of reflectance

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values, from 0.41-1.13% Rr with the vitrinite reflectance at those extremes being basically identical (0.36 and 0.37% Rr, respectively). In all cases, the macrinite had

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lower reflectance values than the adjacent fusinite.

This comparison is complicated because spatial proximity of coal macerals does

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not necessarily imply temporal immediacy. As one example, suberinite- and vitrinitecontaining roots can penetrate older peat layers. Even just considering inertinite

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macerals, fusinite can be formed by charring of the still-living tree while macrinite and

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funginite can be signs of the degradation of the same tree, perhaps when it is still standing, but probably more likely upon its death and fall onto the surface of the mire.

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Proximity in the maceral record can reflect coincidental associations as much as it can

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represent linked events in the depositional history. As such, the time line can be diffuse, comprising contemporaneous events all the way to accidental associations

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representing events separated by decades or more.

3.2. Confocal laser scanning microscopy 3.2.1 Funginite Confocal laser scanning microscopy proved to be an excellent tool in examining the fine structure and morphology of the Eel River funginite. Fig. 1 shows a massive funginite typical of many of the coals in the Eel River sample suite. The multicellular

ACCEPTED MANUSCRIPT fungal sclerotia were over 50-150 μm in largest diameter, displaying rounded, oval to ellipsoidal shape (Fig. 1A, 1C). The margins were smooth to granular and, to some extent, incurved (Fig. 1D, 1H). In some cases, a relatively thick band (<10 μm) was preserved, enveloping the entire fungal body (Fig. 1H) and characterized by fine multilayering, irregularly distributed pores (<1 μm), and concave fractures

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perpendicular to the band.

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The individual hyphae of the fungal sclerotia were predominantly thin-walled and tended to occur in the entire fungal spore (Fig. 1C-1D) or exclusively in its center

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(1F-1H).

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On the other hand, thick walled individual fungal hyphae were located largely at margins of fungal sclerotia, often generating a hyphae -row layered band.

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Interestingly, the hyphae lumens in the hyphae -row layered band were markedly

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smaller in diameter (< 3-4 μm) than the equivalent hyphae in the center of the fungal body (> 6-8 μm). Further, middle lamellae which joined two or more neighboring

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individual fungal hyphae in the layered bands were either well developed, displaying

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well differentiated hyphae walls, or appeared to be fused together, showing only sporadically a fine outline of each individual fungal hyphae wall (Fig. 1H). The

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individual hyphae walls in the fungal sclerotia were often multilayered, reflecting in shape the outline of the cell lumen. The shape of the hyphae lumens was predominantly oval to subangular, often deformed and flattened, leading on occasion to fracturing and defragmentation of cell walls. The hyphae lumens were either entirely unfilled or partially filled with organic material. In most circumstances, middle lamellae of neighboring individual fungal hyphae occurring in the center of the fungal sclerotia closely adjoined one other. In the remaining cases, the areas in-between the

ACCEPTED MANUSCRIPT middle lamellae displayed either a fine-grained appearance or were characterized by open cavities (< 2 μm) and could be easily differentiated from the individual hyphae walls (Fig. 1H). Sclerotia generally arose from densely arranged hyphae surrounded or mantled by an outer layer. The outer layer or the so called “rind” formed from hyphal tips at the periphery of the sclerotium, giving rise to a dense , continuous layer

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(Willetts, 1969; Rothwell, 1972; Massicotte et al., 1992; Scott et al., 2010). Its

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function probably involved resistance against antagonistic microorganisms or unfavorable conditions during growth. On the other hand, the hyphae -row layered

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band may correspond to cortex. Cortex comprises a narrow layer of close -fitting hyphae, serving as an accumulation and storage of reserve materials (Honegger,

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2001). The central part of the sclerotia, i.e., the medulla, formed through interweaving of hyphal filaments; the areas in-between the middle lamellae are attributed to extra

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cellular matrix; and the open cavities to the presence of lacunae (Honegger, 2001;

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Klymiuk et al., 2013, Taylor et al., 2015). Conclusively, the fungal sclerotia constituting the Eel River funginite proved to be a rich source of fungal bodies. The

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well-preserved microstructure of the intact organisms allowed reconstruction of the

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vegetative body morphology and derivation of its possible functions, based on

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comparison with living and fossil fungal organisms.

3.3. SEM-EDS Fig. 2 shows a reflected-light, oil-immersion view of funginite from Eel River sample 8644 (Fig. 2A) and the SEM backscatter images of the same sample (Fig. 2B2D) and EDS spectra (2E-2G) and sample 8654 accompanied by EDS spectra(Fig. 2H and 2I, respectively). The funginite in Fig. 2A and B is an elongated particle with an external cellular network and a sclerified core. This aspect is typical of a rootlet with a

ACCEPTED MANUSCRIPT Hartig network, the locus of water and nutrient exchange between the fungus and the plant, which are produced by many ectomycorrhizal fungi. Fig. 2H is a sub-rounded particle with an external sclerified (thick) layer and a cellular network core. This aspect is frequently found in fungal sclerotia. Both forms are discussed further by O’Keefe et al. (2011b).

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The elements in the cores of the rootlets in sample 8644 [Fig. 2C and 2E, Z1

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EDS spectrum (=Z7)] included marginally detectable amounts of Mg, Al, S and Ca, while the funginite forming in the Hartig network [Fig. 2C and 2D, Z2 EDS spectrum

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(=Z5/Z6/Z8)] Mg and Al were not detected. EDS analysis of the funginite from sample 8654 was remarkably similar to that of the Hartig network funginite in sample 8644

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[Fig. 2H and Z1 EDS spectrum (=Z2)]. Macrinite adjacent to the rootlets had an elemental spectrum virtually identical to that of the funginite [Fig. 2D, F (Z8

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spectrum)]. The inorganic fraction surrounding the funginite in sample 8644 had an

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illite-l type composition, and also include d P-bearing minerals with trace amounts of Ba and Ca, indicating a structure between the phosphates gorceixite and crandallite

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[Fig. 2C, D, and G (Z2 spectrum)]. As seen in Fig. 3, the funginite in sample 8644

etched.

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remained unaffected by the etching, while the surrounding vitrinite was notably

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Shengli sample W6-16 (Figs. 4 and 5) contained loosely consolidated coprolitic macrinite. This was composed of a complex assemblage of macerals and inorganic matter with no orientation planes: agglomerates of small organic frass particles with a spongy structure mixed with fusinite fragments, silicon oxide (Fig. 4) and aluminosilicate (Fig. 5) fragments (probably quartz and clay) were present in the interstitial areas. The latter may be an indication of a rather indiscriminate diet by the

ACCEPTED MANUSCRIPT detritivores, producing the fecal pellets; frass of this size is typically produced by oribatid mites (Feng et al., 2010; Fletcher and Salisbury, 2014).

3.4. Micro Raman spectroscopy

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3.4.1. Funginite

The Raman spectra from the three samples of Eel River coal funginite showed

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three well-developed bands: two at 1365 cm-1 and 1585 cm-1, the D and G bands,

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respectively, and another at ca.1280 cm-1 designated Dl (D left) (Fig. 6A and B). This band was assigned by Li et al. (2007) to a biphenyl stretching vibration.

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A Dr (D right) band, at ca.1451 cm-1, was also present. The D band corresponds to vibrations with A1g symmetry, usually associated with lattice (interlayer)

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arrangement, while Dl and Dr bands are assigned to identical vibrations in small

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aromatic domains (Castiglioni et al., 2001; Li et al., 2007). In the “G band region” two bands, G and Gr (G right) at ca.1585 and 1670 cm-1,

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respectively and one, Gl (G left) near 1520 cm-1 were the main features. The G band

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corresponds to vibrations with E2g symmetry from in-plane aromatic graphene sheets and the Gr band represents a carbonyl C=O structure. The relatively small features on

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the left side of the spectra include an S band (side band) at around 1200 cm-1. Bands S and Gl are a fingerprint for polyacetylene-like structures or areas of conjugated double bonds (Castiglioni et al. 2001). The band Sl (S left) near 1090 cm -1 is possibly assignable to C-H on aromatic domains (Fig. 6A and B). All the bands described for this maceral were also reported by Guedes et al. (2010) for collotelinite, fusinite, and macrinite in a set of coal samples ranging from 0.42 % Rr to 4.22 % Rr. However, Eel River coal funginite shows a distinct pattern, via

ACCEPTED MANUSCRIPT a higher intensity of the Dl band, a distinguishing feature in the Raman spectrum that has not been reported for any other maceral groups (Guedes et al., 2010), using the same excitation wavelength (Fig. 6A and C). These bands were also present in the Eel River coal funginite surrounding material and showed a similar pattern (Fig. 6B and C). However, Eel River coal

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funginite showed distinct features, particularly related to the development of the

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region between the G and D bands in funginite, where the combined intensity of Dr+Gl was lower than in the surrounding material (Fig. 6A and B). This could be related to

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the existence of larger aromatic domains in the structure of this maceral, relative to

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the surrounding material.

3.4.2. Macrinite

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The Raman spectra from the Shengli macrinite particles showed two well

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developed D and G bands at 1366 cm-1 and 1596 cm-1, respectively (Fig. 6D). Satellite features of the D band occurred at ca.1286 cm-1, designated Dl, and at ca.1445 cm-1,

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discussion above.

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designated Dr. The significance of the D, Dl, and Dr bands was noted in the funginite

For the macrinite, G and Gr occurred at ca.1596 and 1693 cm-1, respectively,

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and Gl was near 1522 cm-1. The G band corresponds to vibrations with E2g symmetry from in-plane aromatic graphene sheets and the Gr band represents mainly carbonyl C=O. The chemical associations of the G bands, the S band at 1215 cm -1, and the Sl band at 1090 cm-1 were noted in the funginite discussion.

3.5. Micro-FTIR 3.5.1. Funginite

ACCEPTED MANUSCRIPT Micro-FTIR spectra from the Eel River funginite showed distinct aliphatic hydrogen bands in the aliphatic stretching region (2800-3000 cm-1), an aliphatic bending region (1446 cm-1) and a prominent aromatic carbon band at 1617 cm -1 (Fig. 7A). There was also a shoulder at 1691 cm-1 representing oxygenated groups, likely carbonyl. Aromatic hydrogen bands in the stretching region (3000-3100 cm-1) were not

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detected but there was one band at 829 cm-1 in the out-of-plane region 700-900 cm-1

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that likely represents compounds containing rings with two neighboring C-H groups (Wang and Griffiths, 1985). A relatively broad band with a peak ca.1277 cm-1 was

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assigned to C-O stretch, probably in phenols. Qualitatively, the funginite spectrum was similar to the that of associated vitrinite (Fig. 7A). The difference was small and

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expressed by way of a more distinct shoulder for oxygenated groups in funginite, the

stretching bands in funginite.

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absence of the 829 cm-1 band in vitrinite and relatively higher intensity of the aliphatic

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The areas for band areas in the 2800-3000 cm-1 aliphatic stretching region (Al) and the aromatic carbon plus oxygenated-group region of 1550-1800 cm-1 (C=C+Ox)

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and selected ratios for functional groups are given in Table 2. Unexpectedly, the

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aliphatic stretching region bands in funginite showed generally greater intensity than for vitrinite (avg. 14.4 vs. Avg. 7.5), whereas the average area of the aromatic carbon

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plus oxygenated group region was larger for funginite (61 vs. 56.5). Because of the prominent aliphatic bands, all the ratios involving these bands were higher for funginite than vitrinite (Table 2). Funginite is typically considered to be relatively aromatic (Chen et al., 2012) and inert (Stach, 1982). In contrast, our observations testify against an aromatic nature for funginite and clearly indicate that, at least at the rank studied, funginite can be quite aliphatic. This was supported by a higher CH2 /CH3 ratio for funginite than for the associated vitrinite (2.29 vs. 1.30 (Table 2).

ACCEPTED MANUSCRIPT Higher CH2 /CH3 ratio values reflect longer alkyl chain lengths and less alkyl branching (Lin and Ritz, 1993). Chen et al. (2013) noted greater aliphaticity of funginite because of exsudatinite impregnation. The funginite here appeared to be impregnation-free, suggesting that its aliphatic nature was indigenous. Compared to the adjacent vitrinite, funginite was also characterized by a

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relatively higher abundance of oxygenated groups plus aromatic carbon groups, as

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indicated by the ratio value of 0.42 for funginite and 0.36 for vitrinite. Relatively high aliphaticity and high CH 2/CH3 ratio of the funginite studied

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suggest that it is a reactive maceral, and not inert as automatically assumed from its placing in the inertinite group. Granted, certain inertinites, such as semifusinite, are,

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at least, partially reactive; the point is that funginite is both genetically and chemically distinct from other inertinites. Lower aromaticity and higher CH 2/CH3 ratio than in

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the vitrinite further suggest that funginite has significant oil generation potential.

3.5.2. Macrinite

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Qualitatively, macrinite micro-FTIR spectra showed some differences compared

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with the associated vitrinite (Fig. 7B). The difference between these two was expressed in a more distinct shoulder of oxygenated groups in macrinite, the presence of a

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distinct aliphatic band at 829 cm-1, similar to that from funginite described above, and the absence of other aromatic bands in the out-of-plane 700-900 cm-1 region. There were also some bands for macrinite that were more intense than those for vitrinite and included a 1506 cm-1 band assigned to aromatic ring stretching (Painter et al., 1981) or C-N groups, a 1245 cm-1 band (aromatic C-O stretching), and a 1038 cm-1 band (aliphatic C-O, possibly in ethers; Painter et al., 1985). These last three bands were

ACCEPTED MANUSCRIPT distinct in all macrinite spectra and perhaps could serve as signature features for this maceral. The fusinite spectrum differed from the funginite and macrinite spectra, primarily by the reduced aliphatic stretching region bands (Fig. 7B). However, fusinite was thin walled and impregnated with mineral matter or other macerals; therefore, it

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was impossible to get a reliable spectrum of clean fusinite.

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Semi-quantitatively, the main difference between macrinite and vitrinite was expressed in (1) a relative abundance of aliphatic hydrogen to oxygenated groups (0.51

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for macrinite and 0.92 for vitrinite), attesting to relatively more oxygenated groups and lower alphaticity in macrinite (Table 2) and (2) the oxygenated groups to aromatic

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carbon ratio being higher for macrinite (0.66 vs. 0.27). In addition, the CH2/CH3 ratio was lower for macrinite (1.32 vs. 2.16), suggesting shorter and more branched

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aliphatic chains compared with vitrinite. The higher oxygenated group content and

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lower CH2/CH3 ratio suggest that the macrinite is more aromatic than the associated vitrinite. Further, its lower CH2/CH3 ratio, and consequently lower bond dissociation

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energy (Lin and Ritz, 1993; Walker and Mastalerz, 2004) suggests that macrinite

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needs lower energy for cracking and it will produce less of oil and tar compared to the

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associated vitrinite.

4. Conclusions

Funginite from the Miocene Eel River, California, coals and coprolitic macrinite from the Cretaceous Shengli Formation No. 6 coal, Inner Mongolia, were studied with a variety of petrographic and micro-chemical techniques. The random reflectance of the Eel River funginite is higher than that of the adjacent vitrinite: 0.54-0.74%Rr vs. 0.36-0.46%Rr. The Shengli macrinite has a wide

ACCEPTED MANUSCRIPT range of reflectance (0.41-1.13%Rr), lower than the reflectance from the adjacent fusinite but higher than the 0.26-0.37%Rr of the nearby vitrinite. The confocal laser scanning microscopy enabled examination of detailed structural and morphological characteristics of the Eel River funginite. The observed multicellular fungal sclerotia are > 50-150 μm in widest diameter, showing rounded,

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oval to ellipsoidal form. The inertinite maceral with a cell structure is composed of

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distinctive thin walled or thick walled individual fungal hyphae with well-developed middle lamellae between two or more neighboring individual fungal hyphae. The

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individual hyphae walls in the fungal sclerotia can display a distinctive multilayered concentric to oval structure. Margins of the multilayered fungal body of sclerotia are

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smooth, granular to in-curved. The adjacent thick band (<10 μm) is characterized by fine multilayering, irregular distributed pores (<1 μm) and concave fractures occurring

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perpendicular to the band. SEM-EDS shows that the funginite and macrinite include

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S and Ca; the rootlet interior to the funginite contains Si, Al , S, and Ca; and the surrounding matrix illite and possible gorceixite-crandallite. The coprolitic macrinite

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pellets contain quartz and clay.

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While micro-Raman spectroscopy indicates that the funginite has some indication of an aromatic character, the aliphatic hydrogen bands in the 2800-3000

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cm-1 stretching region and the CH2/CH3 ratio observed with micro-FTIR spectroscopy show that the funginite has a more aliphatic character than the associated vitrinite. The Shengli coprolitic macrinite has a variety of aromatic structures as indicated from micro-Raman spectroscopy. The macrinite micro-FTIR spectra suggest that the maceral has both aromatic and aliphatic features, with the seemingly biggest differences between the vitrinite and macrinite being in the abundance of oxygenated

ACCEPTED MANUSCRIPT groups and in the indication of shorter and more branched aliphatic chains in macrinite than the associated vitrinite. The results of this study emphasize the complex relationships of funginite, macrinite, vitrinite, and the surrounding matrix material that are produced by the interaction of mutualistic fungi with their plant hosts, as well as with decomposers.

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While subtle, there are distinct chemical differences between funginite and other

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macerals, including other inertinite macerals. When funginite is carefully distinguished from other macerals, it is found to lack the Mg and Al found in vitrinite

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and matrix material and is more aliphatic than vitrinite in spite of some aromaticity. Coprolitic macrinite and macrinite (sensu ICCP, 2001) have similar elemental

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distribution to funginite and shorter and more branched aliphatic chains than the associated vitrinite. The results support the conjecture that coprolitic macrinite, at

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least in part, may form in concert with fungal activity (Hower et al., 2009, 2011,

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2013a,b; O’Keefe et al., 2011, 2013a). Overall, the differences between funginite and wood-derived macerals should not be surprising given the very different biologic

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origins of the macerals. Coprolitic macrinite is more complex; some of its origin can

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be traced to the ingestion and excretion of woody material, but that signature is mixed

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with overprints of fungal and bacterial influences.

Acknowledgements The authors thank editor Ralf Littke and reviewer Tim Moore and an anonymous reviewer for their constructive reviews of this manuscri pt. The sample collection from the Shengli Coalfield was supported by the National Natural Science Foundation of China (No. 41420104001).

ACCEPTED MANUSCRIPT References ASTM D5671-95, 2011. Standard Practice for Polishing and Etching Coal Samples for Microscopical Analysis by Reflected Light, ASTM International, West Conshohocken, PA, 2011, www.astm.org. Bartley, R.H., Bartley, S.E., Springer, D.J., Erwin, D.M., 2010. New observations on the Middle Fork Eel River coal-bearing beds, Mendocino County, California, USA. International Journal of Coal Geology 83, 204–228.

CR

IP

T

Beyssac, O., Goffé, B., Petitet, J.-P., Froigneux, E., Moreau, M., Rouzaud, J.-N., 2003. On the characterization of disorder and heterogeneous carbonaceous materials by Raman spectroscopy. Spectrochimica Acta. Part A 59, 2267–2276. Bustin, R.M., Ross, J.V., Rouzaud, J.-N., 1995. Mechanisms of graphite formation from kerogen: experimental evidence. International Journal of Coal Geology 28, 1–36.

AN

US

Castiglioni, C., Mapelli, C., Negri, F., Zerbi, G., 2001. Origin of the D line in the Raman spectrum of graphite: A study based on Raman frequencies and intensities of polycyclic aromatic hydrocarbon molecules. Journal of Chemical Physics 114, 963– 974.

M

Chen, Y., Caro, L.D., Mastalerz, M., Schimmelmann, A., Blandon, A., 2013. Mapping the chemistry of resinite, funginite, and associated vitrinite in coal with micro-FTIR. Journal of Microscopy 249, 1, 69–81.

ED

Chen, Y., Mastalerz, M., Schimmelmann, A., 2012. Characterization of chemical functional groups in macerals across different coal ranks via micro-FTIR spectroscopy. International Journal of Coal Geology 104, 22–33.

PT

Cuesta, A., Dhamelincourt, P., Laureyns, J., Martinez-Alonso, A., Tascon, J.M.D., 1994. Raman microprobe studies on carbon materials. Carbon 32, 1523–1532.

AC

CE

Cuesta, A., Dhamelincourt, P., Laureyns, J., Martinez-Alonso, A., Tascon, J.M.D., 1998. Comparative performance of X-ray diffraction and Raman microprobe techniques for the study of carbon materials. Journal of Materials Chemistry 8, 2875– 2879. Dai, S., Wang, X., Seredin, V.V., Hower, J.C., Ward, C.R., O’Keefe, J.M.K., Li, T., Li, X., Liu, H., Xue, W., Zhao, L., 2012. Petrology, mineralogy, and geochemistry of the Ge rich coal from the Wulantuga Ge ore deposit, Inner Mongolia, China: New data for genetic implications. International Journal of Coal Geology 90-91, 72–90. Dai, S., Liu, J., Ward, C. R., Hower, J.C., Xie, P., Jiang, Y., Hood, M.M., O’Keefe, J.M.K., Song, H., 2015. Petrological, geochemical, and mineralogical compositions of the low-Ge coals from the Shengli Coalfield, China: A comparative study with Ge -rich coals and a formation model for the Wulantuga Ge ore deposit. Ore Geology Reviews 71, 318–349.

ACCEPTED MANUSCRIPT Diessel, K.F., 2010. The stratigraphic distribution of inertinite. International Journal of Coal Geology 81, 251–268. Dyrkacz, G.R., Bloomquist, C.A.A., Horwitz, E.P., 1981. Laboratory Scale Separation of Coal Macerals. Separation Science and Technology 16, 1571–1588. Dyrkacz, G.R., Ruscic, L., Fredericks, J., 1992. An investigation into the process of centrifugal sink/float separations of micronized coals. 1. Some inferences for coal maceral separations. Energy and Fuels 6, 720–742.

IP

T

Dyrkacz, G.R., Bloomquist, C.A.A., Ruscic, L., 1984. High-resolution density variations of coal macerals. Fuel 63, 1367–1373.

CR

Feng, Z., Wang, J., Liu, L.-J., 2010. First report of oribtid mite (arthropod) borings and coprolites in Permian woods from the Helan Mountains of northern China. Palaeogeography, Paleoclimatology, Palaeogeography 288, 54–61.

US

Ferrari, A.C., Robertson, J., 2000. Interpretation of Raman spectra of disordered and amorphous carbon. Physical Review B 61, 14095–14107.

AN

Ferrari, A.C., Robertson, J., 2001. Resonant Raman spectroscopy of disordered, amorphous, and diamondlike carbon. Physical Review B 64, 075414.

ED

M

Fletcher, T.L., Salisbury, S.W., 2014. Probable oribatid mite (Acari: Oribatida) tunnels and faecal pellets in silicified conifer wood from the Upper Cretaceous (CenomanianTuronian) portion of the Winton Formation, central-western Queensland, Australia. Alcheringa 38, 541–545.

PT

Glasspool, I.J., Scott, A.C., Waltham, D., Pronina, N., Shao, L., 2015. The impact of fire on the Late Paleozoic Earth system. Frontiers in Plant Science 6 (article 756), 1– 13.

CE

Green, P.D., Johnson, C.A., Thomas, K.M., 1983. Applications of laser Raman microprobe spectroscopy to the characterization of coals and cokes. Fuel 62, 1013– 1023.

AC

Guedes, A., Valentim, B., Prieto, A.C., Rodrigues, S., Noronha, F., 2010. Micro-Raman spectroscopy of collotelinite, fusinite and macrinite. International Journal of Coal Geology 83, 415–22. Guedes, A., Noronha, F., Prieto, C., 2005. Characterisation of dispersed organic matter from lower Palaeozoic metasedimentary rocks by organic petrography, X-ray diffraction and micro-Raman spectroscopy analyses. International Journal of Coal Geology 62, 237–249. Honegger, R., 2001. The symbiotic phenotype of lichen-forming ascomycetes. In: Esser, K., (Ed.), The Mycota. A comprehensive treatise on fungi as experimental systems for basic and applied research. In: Hock, B (Ed.), volume IX Fungal Associations. Springer, Berlin, Heildeberg, New York, pp. 165–188.

ACCEPTED MANUSCRIPT Hower, J.C., O'Keefe, J.M.K., Watt, M.A., Pratt, T.J., Eble, C.F., Stucker, J.D., Richardson, A.R., Kostova, I.J., 2009. Notes on the origin of inertinite macerals in coals: observations on the importance of fungi in the origin of macrinite. International Journal of Coal Geology 80, 135–143.

T

Hower, J.C., O'Keefe, J.M.K., Eble, C.F., Raymond, A., Valentim, B., Volk, T.J., Richardson, A.R., Satterwhite, A.B., Hatch, R.S., Stucker, J.D., Watt, M.A., 2011. Notes on the origin of inertinite macerals in coal: evidence for fungal and arthropod transformations of degraded macerals. International Journal of Coal Geology 86, 231– 240.

CR

IP

Hower, J.C., O'Keefe, J.M.K., Wagner, N.J., Dai, S., Wang, X., Xue,W., 2013a. An investigation of Wulantuga coal (Cretaceous, Inner Mongolia) macerals: paleopathology of faunal and fungal invasions into wood and the recognizable clues for their activity. International Journal of Coal Geology 114, 44–53.

US

Hower, J.C., Misz-Keenan, M., O'Keefe, J.M.K., Mastalerz, M., Eble, C.F., Garrison, T.M., Johnston, M.N., Stucker, J.D., 2013b. Macrinite forms in Pennsylvanian coals. International Journal of Coal Geology 116–117, 172–181.

AN

International Committee for Coal and Organic Petrology (ICCP), 2001. The new inertinite classification (ICCP System 1994). Fuel 80, 459–471.

M

Jawhari, T., Roid, A., Casado, J., 1995. Raman spectroscopic characterization of some commercially available carbon black materials. Carbon 33, 1561–1565.

PT

ED

Klymiuk, A.A., Taylor, T.N., Taylor, E., Krings, M., 2013. Fossil fungi - Paleomycology of the Princeton Chert II. Dark-septate fungi in the aquatic angiosperm Eorhiza arnoldii indicate a diverse assemblage of root-colonizing fungi during the Eocene. Eocene. Mycologia 105, 1100–1109.

CE

Kramers, H.A., 1927. La diffusion de la lumière par les atomes. Atti Cong. Intern. Fisici, Transactions of Volta Centenary Congress,) Como, 2, 545–557.

AC

Kronig, R. de L., 1926. On the theory of dispersion of X-rays. Journal of the Optical Society of America 12, 547–556. http://dx.doi.org/10.1364/JOSA.12.000547 Li, X., Hayashi, J., Li, C.-Z., 2007. FT-Raman spectroscopic study of the evolution of char structure during the pyrolysis of a Victorian brown coal. Fuel 85, 1700–1707. Lin, R., Ritz, G. P.,1993. Studying individual macerals using i.r. microspectroscopy, and implications on oil versus gas/condensate proneness and “low-rank” generation. Organic Geochemistry 20, 695–706. Lyons, P.C., 2000. Funginite and secretinite - two new macerals of the inertinite maceral group. International Journal of Coal Geology 44, 95–98. Lyons, P.C., Hatcher, P.G., Brown, F.W., 1986. Secretinite: a proposed new maceral of the inertinite maceral group. Fuel 65, 1094–1098.

ACCEPTED MANUSCRIPT Massicotte, H.B., Trappe, J.M., Peterson, R.L.,Melville, L.H., 1992. Studies on Cenococcum geophilum. II. Sclerotium morphology, germination, and formation in pure culture and growth pouches. Canadian Journal of Botany 70, 125-132. Mastalerz, M., Bustin, R.M., 1996. Application of reflectance micro-FTIR in studying macerals; an example from the Late Jurassic to Early Cretaceous coals of the Mist Mountain Formation, British Columbia, Canada. International Journal of Coal Geology 32, 55–67.

IP

T

Moore, T.A., Shearer, J.C., Miller, S.L., 1996. Fungal origin of oxidised plant material in the Palangkaraya peat deposit, Kalimantan Tengah, Indonesia: Implications for 'inertinite' formation in coal. International Journal of Coal Geology 30, 1–23.

CR

Moore, T.A., Swanson, K.M., 1993. Application of etching and SEM in the identification of fossil plant tissues in coal. Organic Geochemistry 20, 769–777.

US

Morga, R., 2014. Raman microspectroscopy of funginite from the Upper Silesian Coal Basin (Poland). International Journal of Coal Geology 131, 65 – 70.

AN

O'Keefe, J.M.K., Hower, J.C., Finkelman, R.B., Drew, J.W., Stucker, J.D., 2011a. Petrographic, geochemical, and mycological aspects of Miocene coals from the Nováky and Handlová mining districts, Slovakia. International Journal of Coal Geology 87, 268–281.

ED

M

O'Keefe, J.M.K., Bechtel, A., Christanis, K., Dai, S., DiMichele, W.A., Eble, C.F., Esterle, J.S., Mastalerz, M., Raymond, A.L., Valentim, B.V., Wagner, N.J., Ward, C.R., Hower, J.C., 2013. On the fundamental difference between coal rank and coal type. International Journal of Coal Geology 118, 58–87.

CE

PT

O’Keefe, J.M.K., Hower, J.C., Hatch, R., Bartley, R.H., Bartley, S.E., 2011b. Fungal forms in Miocene Eel River coals: Correlating between reflected light petrography and palynology. Geological Society of America Annual Meeting, paper 197672 (https://gsa.confex.com/gsa/2011AM/webprogram/Paper197672.html)

AC

Painter, P.C., Rimmer, S.M., Snyder, R.W., Davis, A.. 1981. A Fourier transform infrared study of mineral matter in coal: The application of a least squres curve -fitting program. Appl. Spectrosc., 35, 102–106. http://dx.doi.org/ 10.1366/0003702814731932 Painter, P.C., Starsinic, M., Coleman, M.M. , 1985. Determination of functional groups in coal by Fourier transform interferometry. In: Ferraro, J.R., Basile, L.J. (Eds.), Fourier Transform Infrared Spectroscopy. Academic Press, New York, pp. 169–240. Petersen, H.I., 1998. Morphology, formation and palaeo-environmental implications of naturally formed char particles in coals and carbonaceous mudstones. Fuel 77, 1177– 1183. Rebelo, S., Guedes, A., Lipińska, M.E., Pereira, A.M., Araújo, J.P, Freire, C., 2016. Progresses on the Raman spectra analysis of covalently functionalized multiwall

ACCEPTED MANUSCRIPT carbon nanotubes: unraveling disorder on graphitic carbon materials. Physical Chemistry Chemical Physics, 18, 12784–12796. Rothwell, G.W., 1972. Alaeosclerotium pusillum gen. et sp. nov., a fossil eumycete from the Pennsylvanian of Illinois. Canadian Journal of Botany 50, 2353–2356. Rouzaud, J.-N., Oberlin, A., Beny-Bassez, C., 1983. Carbon films: structure and microtexture (optical and electron microscopy, Raman spectroscopy). Thin Solid Film 105, 75–96.

CR

IP

T

Sadezky, A., Muckenhuber, H., Grothe, H., Niessner, R., Pöschl, U., 2005. Raman microspectroscopy of soot and related carbonaceous materials: spectral analysis and structural information. Carbon 43, 1731–1742. Scott, A.C., 2010. Charcoal recognition, taphonomy and uses in palaeoenvironmental analysis. Palaeogeography, Palaeoclimatology, Palaeoecology 291, 11–39.

AN

US

Scott, A.C., 2015. Thoughts on the problems of coal petrographic nomenclature in relation to the interpretation of peat (coal) forming environments. Geological Society of America Annual Meeting, Baltimore, MD, 1-4 November 2015, Paper 236-8, https://gsa.confex.com/gsa/2015AM/webprogram/Paper266090.html

M

Scott, A.C., Bowman, D.J.M.S., Bond, W.J., Pyne , S.J., Alexander, M., 2014. Fire on Earth: An Introduction. Wiley-Blackwell. 434 pp.

ED

Scott, A.C., Pinter, N., Collinson, M.E., Hardiman, M., Anderson, R.S., Brain, A.P.R., Smith, S.Y., Marone, M.F., Stampanoni, M., 2010. Fungus, not comet or catastrophe , accounts for carbonaceous spherules in the Younger Dryas ‘impact layer’. Geophysical Research Letters 37, L14302.

CE

PT

Stach, E., 1982. The macerals of coal. In: Stach, E., Mackowsky. M, Teichmüller, M., Taylor, G.H., Chandra, D., and Teichmüller, R.(Eds.), Stach's Textbook of Coal Petrology. Gebrüder Borntraeger, Berlin-Stuttgart, pp. 87–140.

AC

Taylor, G.H., Teichmüller, M., Davis, A., Diessel, C.F.K., Littke, R., Robert, P., 1998. Organic Petrology. Gebrüder Bornträger, Berlin, Stuttgart, 704 pp. Taylor, T.N., Krings, M., Taylor, E., 2015. Fossil Fungi. 1st Edition. Elsevie r, Amsterdam, Boston, Heidelberg, London, 382 pp. Taylor, T.N., Taylor, E.L., 1997. The distribution and interactions of some Paleozoic fungi. Review of Palaeobotany and Palynology 95, 83–94. Tuinstra, F., Koenig, J.L., 1970. Raman spectrum of graphite. The Journal of Chemical Physics 53, 1126–1130. Walker, R., Mastalerz, M., 2004. Functional group and individual maceral chemistry of high volatile bituminous coals from southern Indiana: controls on coking. International Journal of Coal Geology 58, 181–191.

ACCEPTED MANUSCRIPT Wang, S.H., Griffiths, P.R., 1985. Resolution enhancement of diffuse reflectance i.r. spectra of coals by Fourier self-deconvolution. 1. C-H stretching and bending modes. Fuel, 64, 229–236. Willetts, H.J., 1969. Structure of the outer surfaces of sclerotia of certain fungi. Archives of Microbiology 69, 48–53.

T

Yoshida, A., Kaburagi, Y., Hishiyama, Y., 2006. Full width at half maximum intensity of the G band in the first order Raman spectrum of carbon material as a parameter for graphitization. Carbon 44, 2333–2334.

AC

CE

PT

ED

M

AN

US

CR

IP

Zerda, T.W., Xu, W., Zerda, A., Zhao, Y., von Dreele, R.B., 2000. High pressure Raman and neutron scattering study on structure of carbon black particles. Carbon 38, 355– 361.

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Fig. 1. CLSM image of Eel River coal samples with oil objective 63× and 1.32 NA by application of Ar and He /Ne-lasers ](excitation 458, 496 and 633nm laser lines; emission 459-491, 501-629 and 638-800 nm): (A) typical massive funginite (sample 8644, image 28; scan format 1024 × 1024); (B) magnification of dashed square in “A” (image 30; scan format 1024 × 1024); (C) round funginite (sample 8650, image 40; scan format 512 × 512); (D) magnification of dashed square in “C” (image 42; scan format 512 × 512); (E) round funginite (sample 8650, image 09; scan format 512 × 512); E1 and E2) magnification of dashed squares in “E” (images 11 and 13; scan formats 512 × 512); (F) funginite fragment (sample 8650, image 24; scan format 512 × 512); (G) magnification of dashed square in “F” (image 22; scan format 512 × 512); (H) magnification of dashed square in “G” (image 20; scan format 512 × 512). The cell walls near the external layer are very thick. Fig. 2. Micrographs and EDS analysis of sample 8644 Area 1.

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(A) Photo in oil-immersion, reflected light microscopy: examples of funginite; (B) same as in “A” seen under SEM-EDS (×1000; BSE); (C) magnification (2000x; BSE) of “B” Area 1 (Z1, rootlet; Z2, funginite; Z3, mineral matrix);(D) magnification (2000x; BSE) of “B” Area 2 (Z4, mineral matrix; Z5, funginite; Z6, funginite; Z7, rootlet; Z*, macrinite); (E) Z1 and Z7 EDS spectrum of rootlet core;(F) Z5, Z6, and Z8 EDS spectrum of funginite (Harwig network); (G) Z3 and Z4 EDS spectrum of inorganic matter; (H) SEM image of funginite; (I) Z1 and Z2 spectrum of funginite

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Fig. 3. Funginite in Eel River sample 8654. (A) Oil immersion objective, reflected light microscopy image; (B) same maceral under SEM before etching (1000x, BSE); (C) after etching with (1000x, BSE); (D) 100% contrasting image after (after etching; 750x, BSE).

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Fig. 4. Micrographs and EDS analysis of sample W6-16 area 2. (A) Photo in oil immersion reflected light microscopy; (B) square area in “A” under SEM (×1000x; BSE), (Z1) EDS spectrum of organic ovoid bodies; (Z3) EDS spectrum of interstitial zones; (Z4) EDS spectrum of quartz. Fig. 5. Micrographs and EDS analysis of sample W6-16 area 1; (A) Photo in oil immersion reflected light microscopy; (B) square area in “A” seen under SEM (500x; BSE); (C) magnification (2000x; BSE) of square area in “B”; (D) magnification (5000x; BSE) of square area in “C”; (Z1) EDS spectrum of organic ovoid body; (Z2) EDS spectrum of interstitial zones; Z4). Fig. 6. Micro Raman results: (A and B) Example of deconvolution pattern of a spectrum from funginite (A) and surrounding material (B); (C) representative Raman

ACCEPTED MANUSCRIPT spectrum obtained from funginite (1) and surrounding material (2); (D) example of deconvolution pattern from a spectrum obtained from macrinite. Fig. 7. Micro-FTIR spectra: (A) Eel River coal funginite and vitrinite; B) Shengli coal macrinite, vitrinite and fusinite (each spectrum represents an average of six individual spectra of vitrinite and funginite, and four of macrinite(because of unavailability of large enough fusinite, fusinite spectrum is one single spectrum of the largest and purest fusinite found).

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Table 1 Average reflectance and standard deviation of reflectance for funginite and vitrinite (Eel River samples 8644, 8650 and 8654) and macrinite, fusinite, semifusinite, and vitrinite (Shengli No. 6 samples W6 18, W6 18, and W6 8). Multiple associations were measured from each of the samples.

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Table 2 Integration areas of 2800-3000 cm-1 and 1550-1800 cm-1 regions and selected FTIRderived ratios of vitrinite, funginite, and macrinite.

ACCEPTED MANUSCRIPT 2 Funginite 0.68 0.02

3 Vitrinite Funginite Vitrinite 0.49 0.73 0.54 0.00 0.03 0.20

%Rr Std

0.54 0.01

0.36 0.02

0.59

0.46

8654

%Rr Std

0.65

0.46

0.73 0.04

0.48 0.03

W6 18

%Rr Std

W6 18 (cont.)

%Rr Std

Macrinite Fusinite Semifusinite Vitrinite Macrinite Fusinite Semifusinite 0.41 0.36 0.44 0.04 0.00 0.10 1.08 0.21

0.77 0.04

1.13 0.06

0.74 0.27

0.49 1.16 0.80 %Rr 0.06 0.21 Std a average random reflectance of particle or cluster; b average of particle or cluster.

0.88

M

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W6 8

0.27 0.03

US

0.69 0.11

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Table 1

Vitrinite 0.46 0.01

0.50 0.03

CR

Shengli coal Sample

0.73

IP

8650

4 Funginite 0.70 0.02

T

1 Eel River coal Sample Funginite Vitrinite 0.74 0.48 %Rar 8644 Std b 0.00 0.01

Vitrinite 0.26 0.02 0.37 0.05

ACCEPTED MANUSCRIPT Table 2 2800-3000 cm-1

Sample

1550-1800 Al/C=C+Oxa Al/Oxa Al/C=Ca Ox/C=Ca CH2 /CH3a cm-1

8.2

61

0.13

0.40

0.18

0.44

1.86

8654 vit2

5.9

55.3

0.11

0.63

0.08

0.13

1.10

8654 vit3

8.7

56.9

0.15

0.57

0.20

0.35

T

1.19

8654 vit4

5.3

54.3

0.10

0.36

0.13

0.35

0.92

8650 vit5

11.2

49.2

0.23

0.50

0.21

0.42

0.87

8644 vit6

5.5

62.5

0.09

0.16

0.07

0.45

1.84

Average

7.5

56.5

0.13

0.43

0.14

0.36

1.30

8654 fung1

15.7

65.2

0.24

1.01

0.38

0.38

2.17

8654 fung2

11.3

54.8

0.21

0.98

0.33

0.34

1.40

8654 fung3

13.2

68.1

0.19

8654 fung4

7.8

52

8654 fung5

9.7

51.9

8650 fung6

28.5

74.1

Average

14.4

61

US

Funginite

CR

Vitrinite 8654 vit1

IP

Eel River coal

0.43

0.46

2.89

0.91

0.51

0.56

2.25

0.19

0.87

0.29

0.33

1.06

0.38

1.45

0.66

0.46

3.95

0.23

1.03

0.43

0.42

2.29

33.4

0.10

0.24

0.09

0.39

1.67

33.4

0.22

1.43

0.34

0.24

1.85

40.7

0.19

1.07

0.20

0.18

2.97

33.3

0.17

0.47

0.19

0.40

1.52

7.1

26.8

0.26

0.72

0.22

0.31

1.41

6.5

25.1

0.26

0.86

0.36

0.42

1.04

6.2

32.1

0.17

0.92

0.21

0.27

2.16

W6 18 mac 1

8.4

40.3

0.21

0.78

0.23

0.29

0.97

W6 18 mac 2

7.9

33

0.24

0.54

0.38

0.70

1.47

W6 18 mac 3

6.8

32

0.21

0.55

0.35

0.63

1.10

W6 18 mac 4

4.3

42

0.10

0.18

0.18

1.00

1.74

W6 18 vit2

7.2

W6 18 vit3

7.6

W6 18 vit 4

5.5

CE

3.4

W6 18 vit 5

Macrinite

AC

W6 18 vit 6 Average

PT

Vitrinite W6 18 vit1

M

ED

Shengli coal

AN

0.95

0.15

Average 6.9 36.8 0.19 0.51 0.28 0.66 1.32 a Al, aliphatic stretching 2800-3000 cm-1 ; C=C+Ox 1550-1800 cm-1 aro mat ic carbon plus oxygenated group region; Ox, band with peak at ca.1700 cm-1 after deconvolution; C=C, aro mat ic carbon band with peak at ca. 1620 cm-1 after deconvolution; CH2 /CH3 , ratio of CH2 band with peak at ca.2923 cm-1 to CH3 band with peak at ca.2963 cm-1 after deconvolution.

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Figure 7

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Miocene funginite and Cretaceous coprolitic macrinite were investigated The latter inertinite macerals have higher R than associated vitrinite Despite that, they are more aliphatic than other inertinites

AC

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