ライフサイエンスコーパス: Archean

1 red from the atmosphere to the mantle in the Archean.

2 e of a vast microbial ecosystem in the early Archean.

3 ore reducing conditions prevalent during the Archean.

4 those identified several times later in the Archean.

5 for the Hadean (pre-3,800 Myr ago) and Early Archean (3,800 to 3,400 Myr) impact flux can be derived

6 he scarcity of well-preserved rocks from the Archean (4.0 to 2.5 Gyr ago) and Proterozoic (2.5 to 0.5

7 Late Archean accretionary events involving an oceanic lithosp

8 nt porosity, limiting the potential for post-Archean additions of organic matter to the samples.

9 oxides and molecular oxygen generated during Archean and earliest Proterozoic non-Snowball glacial in

10 n--although often overlooked--constituent of Archean and Early Proterozoic sedimentary successions.

11 e-Ni) sulfide ore deposits formed during the Archean and early Proterozoic.

12 fractionation of sulfur isotopes (S MIF) in Archean and Paleoproterozoic rocks provides strong evide

13 ing microbes had already evolved by the late Archean and were present before oxygen first began to ac

14 in bedded carbonaceous cherts from the Early Archean Apex Basalt and Towers Formation of northwestern

15 scovered in a bedded chert unit of the Early Archean Apex Basalt of northwestern Western Australia.

16 asinal environments adjacent to a major Late Archean ( approximately 2.6-2.5 Ga) marine carbonate pla

17 The low O2 content of the Archean atmosphere implies that methane should have been

18 on of sulfur isotopes that took place in the Archean atmosphere of Earth.

19 The Archean atmospheric Xe is mass-dependently fractionated

20 Here, we show that the early Archean banded rocks from Isua, Akilia, and Innersuartuu

21 is a tonalite intrusion associated with the Archean Barberton Greenstone Belt.

22 at the atmospheric oxygen level rose from an Archean baseline of essentially zero to modern values in

23 rker preservation, so future exploration for Archean biomarkers should screen for rocks with milder t

24 On average, therefore, the Archean biosphere may have been oxidizing at the bottom

25 ous ages, as well as modern, Cretaceous, and Archean black shales.

26 ndicate that the titanite formed during late Archean ca. 2.9 Ga thermal contact metamorphism and not

27 Mesoproterozoic, Paleoproterozoic, and some Archean conical stromatolites.

28 The crustal remnants of Earth's Archean continents have been shielded from mantle convec

29 ounts of differentiated mantle-derived melt, Archean crust and hydrothermally altered shallow-crustal

30 -143)Nd data reveal that this large block of Archean crust formed by reworking of much older (>4.2 bi

31 the addition of deep mantle material to the Archean crust, oceans, and atmosphere, while also provid

32 n years to form an important source rock for Archean crustal genesis.

33 ew lherzolitic and eclogitic diamonds to the Archean diamond suite.

34 ean island basalt, the HIMU source formed as Archean-early Proterozoic subduction-related carbonatite

35 The Archean Earth (3.8 to 2.5 billion years ago) was probabl

36 diation screening required to protect DNA on archean Earth compare well with field and laboratory obs

37 On the anoxic Archean Earth, the oxidized partner was probably iron.

38 even under the high UV radiation regimes of archean Earth.

39 timate biologically effective irradiances on archean Earth.

40 ulfur allotropes in the anoxic atmosphere of Archean Earth.

41 and Hf isotopic mixing arrays show that the Archean EM I material was poor in trace elements, resemb

42 ndamental insights into the chemistry of the Archean environment and evolutionary origin of microbial

43 was an important metabolism in organic-rich Archean environments--even in an Archean ocean basin dom

44 se in mantle (182)W/(184)W occurs during the Archean eon (about four to three billion years ago), pot

45 d into arsenic-rich environments in the late Archean Eon and Proterozoic Eon, respectively, by the sp

46 e same S-isotope pattern at both ends of the Archean Eon is unexpected, given the complex atmospheric

47 The Archean Eon witnessed the production of early continenta

48 the Cretaceous Oceanic Anoxic Events and the Archean Eon.

49 bilized the craton and contributed a younger Archean generation of eclogitic diamonds.

50 water signal may be representative of a late Archean global signature and that it preceded a similar,

51 This Middle Archean gold mineralization event corresponds to a perio

52 rchean in age and, with the exception of the Archean grain, are also matched by the population in the

53 it has been proposed that during the Hadean-Archean heavy bombardment by extraterrestrial impactors,

54 in Archean terrigenous sedimentary rocks and Archean igneous/metaigneous rocks to track the bulk MgO

55 tone are Permian, Devonian, Proterozoic, and Archean in age and, with the exception of the Archean gr

56 fur isotope data implying that the sulfur in Archean komatiite-hosted Fe-Ni sulfide deposits was prev

57 Estimates of fO2 of Archean magmas are not this low, arguing for alternative

58 ble for the rise in oxygen, it requires that Archean magmas had at least two orders of magnitude lowe

59 Middle Archean mantle depletion events initiated craton keel fo

60 report the occurrence of phosphite in early Archean marine carbonates at levels indicating that this

61 Late Archean metamorphism significantly reduced the kerogen's

62 and reveal the progressive development of an Archean microcontinent.

63 very substantiates previous reports of Early Archean microfossils in Warrawoona Group strata.

64 In the late Archean, molecular oxygen likely cycled as a biogenic tr

65 on metals molybdenum and rhenium in the late Archean Mount McRae Shale in Western Australia.

66 Iron speciation data for the late Archean Mount McRae Shale provide evidence for a euxinic

67 Archean mutinaite might have become de-aluminated toward

68 We propose that Archean negative Fe isotope excursions reflect partial F

69 rganic-rich Archean environments--even in an Archean ocean basin dominated by iron chemistry.

70 The Archean ocean is efficient in diluting primary atmospher

71 ano, Indonesia, a low-sulfate analog for the Archean ocean, we find large (>20 per mil) sulfur isotop

72 h predominantly bound metals abundant in the Archean ocean.

73 bdenum and rhenium were probably supplied to Archean oceans by oxidative weathering of crustal sulfid

74 sibly restricting biological productivity in Archean oceans.

75 potentially catalyzed redox reactions in the Archean oceans.

76 ealed modern bacteria, perhaps indicative of Archean ones.

77 lion-year-old (uranium-lead ratio in zircon) Archean ophiolite complex in the North China craton.

78 The documentation of a complete Archean ophiolite implies that mechanisms of oceanic cru

79 If active during the Archean, pelagic precipitation and subsequent sedimentat

80 two critical roles for carbon dioxide in the Archean period.

81 We infer an increase from early Archean pH values between 6.5 and 7.0 and Phanerozoic v

82 t nutrients phosphorus and nickel across the Archean-Proterozoic boundary, which might have helped tr

83 on the thermal and chemical evolution of the Archean-Proterozoic Earth.

84 f noble gases trapped in fluid inclusions of Archean quartz (Barberton, South Africa) that reveal the

85 e mass-independent fractionation line of the Archean rock record.

86 resulted in parallel transposition of Early Archean rocks and significant boudinage, the tails of wh

87 Hopanes and steranes found in Archean rocks have been presented as key evidence suppor

88 Archean rocks may provide a record of early Earth enviro

89 dation state phosphorus compounds in ancient Archean rocks.

90 erse tectonic settings, including five early Archean samples from Isua, Greenland, of which three hav

91 results demonstrate that previously studied Archean samples host mixtures of biomarker contaminants

92 ongly with multiple sulfur isotope trends in Archean samples, which exhibit significant (36)S anomali

93 Because the main ingredient of the Archean sea was sodium bicarbonate, neither archeobacter

94 r conditions that model the chemistry of the Archean sea.

95 d by sulfur cycling in Lake Matano, we infer Archean seawater sulfate concentrations of less than 2.5

96 fur isotope fractionations into estimates of Archean seawater sulfate concentrations.

97 es predict uniformly negative Delta(33)S for Archean seawater sulfate, this remains untested through

98 After subduction, this Archean sediment apparently remained stored in the deep

99 erial was poor in trace elements, resembling Archean sediment.

100 at archaea and bacteria were present in Late Archean sedimentary environments.

101 sotopes (reported as Delta(33)S) recorded in Archean sedimentary rocks helps to constrain the composi

102 The presence of these anomalies in Archean sediments [(4-2.5 billion years ago, (Ga)] impli

103 ude of minor sulfur isotope fractionation in Archean sediments remain unexplained.

104 arbon for a 150 million-year section of late Archean shallow and deepwater sediments of the Hamersley

105 re determined by the size of the preexisting Archean siderite reservoir, which was consumed through o

106 e mass-independent fractionation (S-MIF), an Archean signature of atmospheric anoxia that begins to d

107 we show that subduction processes formed the Archean Slave craton in Canada.

108 Proterozoic rocks exist, no currently known Archean strata lie within the appropriate thermal maturi

109 candidate traces of life can be confirmed in Archean subseafloor environments.

110 to the sediments likely results from a Late Archean subsurface hydrothermal biosphere of archaea and

111 malies, thus questioning the significance of Archean sulfate deposits.

112 mosphere but identify variability within the Archean sulfate isotope record that suggests persistence

113 ch allows us to investigate the diversity of Archean sulfate texture and mineralogy with unprecedente

114 regions, allowing for reconstruction of the Archean sulfur cycle and possibly offering insight into

115 ng an integrated biogeochemical model of the Archean sulfur cycle, we find that the preservation of m

116 ass-anomalous fractionations expected of the Archean sulfur cycle, whereas values show large fraction

117 n on to deconvolute the ocean and atmosphere Archean sulfur cycle.

118 atmosphere has implications for interpreting Archean sulfur deposits used to determine the redox stat

119 We used Ni/Co and Cr/Zn ratios in Archean terrigenous sedimentary rocks and Archean igneou

120 Here we show that in the Archean, the formation and stabilization of continents a

121 evated atmospheric CO2 concentrations in the Archean, the sustained methane fluxes necessary for haze

122 emains untested through the vast majority of Archean time.

123 he reaction would have continued through the Archean to at least the early phases of the Great Oxidat

124 ccount evidence from sulfur isotope data for Archean to early Proterozoic surface material in the dee

125 t full-vector paleointensity measurements of Archean to Hadean zircons bearing magnetic inclusions fr

126 sedimentary delta(56)Fe(pyrite) recorded in Archean to modern sediments.

127 cks to track the bulk MgO composition of the Archean upper continental crust.

128 enesis may have evolved during or before the Archean, when methane could have been key to Earth's ear

129 In the low-oxygen Archean world (>2400 million years ago), seawater sulfat