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Geology (地質学)

Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

an earth science concerned with the solid earth, the rocks of which it is composed and the processes by which they change over time

Geological timescale


Stratigraphy (層序学/層位学)

a branch of geology concerned with the study of rock layers (strata) and layering (stratification)
Table. Geological timescale, based on Family Waagenophyllidae (Kanmera 1973, 勘米良亀齢)
Era_______Fusulinida band (フズリナ属帯)

Lower: -


Upper: Palaeofusulina, Codonofusiella
Middle: Yabeina, Neoschwagerina, Cancellina
Lower: Misellina, Pseudofusulina, Pseudowagerina


Upper: Triticites
Middle: Fusulina-Fusulinella

Fig. 1.76. Morphology of Fusulinidae (紡錘虫). (a) Fusulinella. (b) Yabeina. A-A': axis of coiling, pr: proloculus, spi: spirotheca, s: septa, sp: septal pores, sf: septal fluting, c: chomata, t: tunnel, ef: external furrow, pts: primary transverse septula, sts: secondary transverse septula, as: axial septula, a: antetheca, pc: parachomata, f: foramina, lp: lateral passage. (Modified after Maklukho-Maclay et al. 1959).
marine ecosystem
Fig. 3.9. Interrelationships of life habits within the marine ecosystem.
  • Habitat: Feeding type
  • Planktonic:
    Herbivores = Gastropods (Pteropods)
  • Nektonic:
    Filter feeders = Pelecypods (Scallops)
    Carnivores/Scavengers = Belemnoids, Nautiloids, Ammonoids, Trilobites, Echinoids
  • Vagrant benthonic:
    Filter feeders = Trilobites
    Herbivores = Gastropods, Echinoids
    Carnivores/Scavengers = Gastropods, Nautiloids, Ammonoids, Trilobites, Echinoids
  • Sessile benthonic epifauna (and epiphyta):
    Autotrphs = Algal stromatolites, Calcareous algae
    Filter feeders = Corals, Tabulates, Stromatoporoids, Sponges, Bryozoans, Brachiopods, Pelecypods, Crinoids, Blastoids
    Carnivores/Scavengers = Corals
  • Benthonic infauna:
    Filter feeders = Pelecypods, Brachiopods
    Sediment feeders: Pelecypods, Echinoids
    Carnivores/Scavengers = Gastropods, Trilobites
Fig. 5.34. Carboniferous coral zones and brachiopod/coral subzones, British Isles (Stamp 1950). An introduction to stratigraphy British Isles. Subzones: K1: Productus basus, K2: Spiriterina octoplicata, Z1: Spirifer tornacensis, Z2: Zaphrenus konincki, C1: Caninia cylindrea, C2: Palaeosmilia φ, S1: Caninia bristolensis, S2: Productus corrugato-hemisphericus, D1: Dibunophyllum bourtonense, D2: Lonsdaleia floriformis. (Yaughan 1905)

Mineralogy (鉱物学)

Rock (岩石・岩)
Table. Major minerals that form volcanic rocks. The chemical equiations are simplified. All the minerals except silica minerals forms various degrees of solid dispersion.
colorless mineral (無色鉱物)

plagioclase (斜長石)

CaAlsSi2O8 (anorthite 灰長石), An [→ abbreviation of terminal component]
NAAlSi3O8 (albite 曹長石), Ab

potassium feldspar (カリ長石)

KalSi3O8, Or

feldspathoid (準長石)

NaAlSiO4 (nephelite 霞石), Ne
KalSi2O6 (leucite 白榴石), Lc

silica minerals (珪酸鉱物)

SiO2 (quartz 石英・tridymite 鱗珪石・cristobalite 方珪石)

Colored mineral (有色鉱物)

peridotite (橄欖岩)

(Mg, Fe)2SiO4

pyroxene (輝石)

(Mg, Fe)SiO3 (orthopyroxene 斜方輝石)
(Ca, Mg, Fe)SiO3 (clinopyroxene 単斜輝石)

amphibole (角内石)

(Ca, Mg, Fe, Na, Al)7-8[(Al, Si)4O11]2(OH)2

biotite (黒雲母)

K(Mg, Fe)3[(AlSi3)O10](OH)2

magnetite (磁鉱鉱)

Fe2+, Fe3+2O4 (incluidng a small amount of Ti, Mn, etc.)

volcanic glass (火山ガラス)

silicate glass containing Mg, Fe, Ca, Na, K, Al, etc.

lava (溶岩)

Lithology (岩石学)

Igneous rocks (火成岩)

Sedimentary rock (堆積岩)

Regolith (レゴリス): a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock, e.g.,

pedolith (ぺドリス) ≈ soil: a surface formation that has undergone one or more pedogenic processes
alluvium (沖積層) (and other transported cover)

upper saprolite: completely oxidized bedrock
lower saprolite: chemically reduced partially weathered rocks
saprock: fractured bedrock with weathering restricted to fracture margins

tephra and lava (火山噴出物)
duricrust (表面固化物): formed by cementation of soils
biota and the organic components

Serpentine belt (蛇紋岩帯)

Serpentine (蛇紋岩)

A rock composed of one or more serpentine group minerals
Serpentine group minerals
Minerals in this group are formed by serpentinization, a hydration and metamorphic transformation of ultramafic rock from mantle.
Serpentine soil
  • low Ca/Mg ratio
  • lack of essential nutrients, N, K and P
  • ultramafic, due to heavy metals


Serpentine zone supports diverse wildflowers that are occasionally rare or endangered species, such as Primula takedana and Berberis amurensis var. japonica.
Species sepcifically established in serpentine zones can be used as ecological indicator
Plants in the serpentine zone of Teshio, northern Hokkaido
Achillea ptarmica L. var. yezoensis Kitamura (ホソバエゾノコギリソウ)
Berberis amurensis Rupr. var. japonica (Regel) Rehd. (ヒロバノヘビノボラズ)
Euphorbia sieboldiana Morr. et Decne. var. montana Tatew. (ヒメナツトウダイ)
Japonolirion osense Nakai (テシオソウ)
Picea glehnii Masters (アカエゾマツ)
Primura takedana Tatew. (テシオコザクラ)
Thymus quinquecostatus Celak. (イブキジャコウソウ)

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