PREVIOUS TABLE OF CONTENTSAppendix C
Thin-Section Descriptions
K-99-14 Bratsburg [3]
Macroscopic: laminated (stromatolitic?)
Crude remnant layering strongly present. Micro-vugs common; filled with chalcedony and fine druse. Chalcedony shows strong brown (iron-oxide?) staining. Massive portions of chert show light brown staining. Microscopic carbonate (?) inclusions present in hazy irregular patches.
K-99-43 Stockton Hill [5]
Macroscopic: fine homogeneous
Weak remnant layering present. Made up entirely of poorly-preserved ooids ~1mm in diameter. Occassional fine drusy veins £ 1mm wide, lined with chalcedony. Light brown stain over everything but druse, darker in chalcedony and between ooids.
K-99-55 Wilson [6]
Macroscopic: mottled
Chaotic ribbony texture of finer/coarser zones (perhaps remnant sedimentary structures like mud clasts?). Micro-vugs £ 1mm with chalcedony and druse. Scattered opaque inclusions ~1mm with iron-oxide rims. Light brown stain, darker in chalcedony and finer-grained matrix zones.
K-99-74 Treasure Island [7]
Macroscopic: finely laminated (stromatolitic?)
Strongly laminated; defined by subtle grain-size changes and amount of microscopic opaques. Light brown stain over all. Notable lack of chalcedony or druse. Rare tiny carbonate inclusions £ 0.1mm in diameter.
K-99-86 Lake City Quad [8]
Macroscopic: very sandy
Very Coarse-grained, £ 4mm diameter clasts; contains well-rounded quartz sand, ooids (many polygonally-cracked), rounded mud and carbonate clasts (polygonally cracked). Clasts: ~40% sand grains, 40% ooids, 10% carbonate, 10% mud.
K-99-87 Lake City Quad [8]
Macroscopic: very oolitic
Extremely well-defined oolitic (0.5 – 2 mm) texture. Ooids coarsen inwards internally, and are lined on exterior with chalcedony. <5% of ooids still contain carbonate. Light brown staining of matrix and chalcedony does not penetrate ooids.
K-99-91 Zumbro River [9]
Macroscopic: very sugary; translucent
Very massive and homogeneous. A few vugs £ 3mm diameter, containing fine druse. Virtually no iron-oxide staining.
K-99-96 Zumbro River [9]
Macroscopic: sandy; slightly banded
Coarse-grained; sub-rounded sand grains £ 1mm with oolitic overgrowths, ~10% of ooids without sand cores. Minor bits of chalcedony between some ooids. A few small areas of carbonate. Light brown stain over all.
K-99-116 Stillwater [11]
Macroscopic: very oolitic (interiors of ooids show tendency to weather out)
Extremely oolitic, 0.5 - 1mm ooids suspended (sometimes touching) in fine homogeneous matrix. Ooids coarsen inwards internally. Pale brown staining of matrix; darker brown staining of outermost layers of ooids.
K-99-123 Hudson [12]
Macroscopic: mottled sugary; some goethite inclusions
Extremely homogeneous, "medium-grained" chert. Rare 0.5mm carbonate crystal inclusions. No iron-oxide staining.
K-99-138 King Coulee [13]
Macroscopic: slight beige/gray mottling; slightly ribbony
Faint layering visible. Poorly-preserved remnant ooids (£ 1mm) throughout. Sometimes clay-rich matrix. Rare vugs £ 2mm with chalcedony. Strong brown staining throughout.
K-99-170 Shakopee [16]
Macroscopic: very oolitic
Quartz sand £ 1mm with oolitic/chalcedony overgrowths; overgrowths have light-brown stain. Homogeneous matrix.
K-99-201 Elmwood [20]
Macroscopic: fine homogeneous
Ribbony relict sedimentary structure. Relict fossils (spicules and shell cross-sections) recrystallized to chalcedony - up to 8mm long. Extremely fine homogeneous matrix. Scattered carbonate inclusions ~0.1mm. Very light brown stain throughout.
Intro and Background Fieldwork Sample Prep Data Analysis PCA Correspondence Analysis Stepwise DA
Discriminant Analysis More PCA Element Trends Conclusions Bibliography Appendix A: Part 1 Part 2 Part 3 Part 4 Part 5 Appendix B Appendix C