DOI: 10.1017/s0016756800026066. Chlorite-mica stacks in low-strain rocks from central Wales

Chlorite-mica stacks in low-strain rocks from central Wales

10.1017/s0016756800026066

Crossref journal-article

Cambridge University Press (CUP)

Geological Magazine (56)

Abstract

SummaryWeakly deformed, low grade, Lower Palaeozoic metasediments from central Wales contain abundant stack-like intergrowths of chlorite and white mica that closely resemble stacks described from the Devonian Hunsruckschiefer of West Germany; the Ordovician Martinsburg Slate, New Jersey, U.S.A.; and elsewhere. Several theories have been proposed to explain the origin of such stacks, including a detrital origin; strain-controlled growth of chlorite on a detrital mica nucleus; and strain-controlled intergrowth during metamorphism. None of these satisfactorily explains the central Wales stacks. A detrital origin is precluded by the presence of many stacks with shapes too delicate to have survived transportation, and a lack of hydrodynamic equivalence between the stacks and the clastic host grains. Features inconsistent with strain-controlled growth are constant alignment parallel to bedding but non-systematic orientation with respect to tectonic cleavage, their common occurrence in undeformed rocks, and petrographic evidence that they precede the tectonic cleavage. It is proposed that the stacks formed during diagenesis and low-grade metamorphism, and before the onset of deformation, through mimetic growth on a primary bedding fabric composed of clay minerals.

Bibliography

Craig, J., Fitches, W. R., & Maltman, A. J. (1982). Chlorite-mica stacks in low-strain rocks from central Wales. Geological Magazine, 119(3), 243â256.

Authors 3

J. Craig (first)
W. R. Fitches (additional)
A. J. Maltman (additional)

References 26 Referenced 47

{'key': 'S0016756800026066_ref002', 'volume-title': 'Atlas of Rock Cleavage', 'author': 'Bayly', 'year': '1977'} / Atlas of Rock Cleavage by Bayly (1977)
10.1002/gj.3350020311
10.1144/gsjgs.138.4.0475
{'key': 'S0016756800026066_ref022', 'first-page': '3', 'article-title': 'Gefugeuntersuchungen an transversalgeschieferten Gesteinen aus dem ostlichen Rheinischen Schiefergebirge (Ein Beitrag zur Genese der transversalen Schieferung)', 'volume': 'D 15', 'author': 'Weber', 'year': '1976', 'journal-title': 'Geologisches Jahrbuch'} / Geologisches Jahrbuch / Gefugeuntersuchungen an transversalgeschieferten Gesteinen aus dem ostlichen Rheinischen Schiefergebirge (Ein Beitrag zur Genese der transversalen Schieferung) by Weber (1976)
{'key': 'S0016756800026066_ref012', 'first-page': '245', 'volume-title': 'Conference Report: Deformation of soft sediments', 'volume': '135', 'author': 'Fitches', 'year': '1978'} / Conference Report: Deformation of soft sediments by Fitches (1978)
10.1180/claymin.1976.011.2.08
{'key': 'S0016756800026066_ref006', 'first-page': '123', 'article-title': 'Petrology of Ordovician sediments in Wales', 'volume': '51', 'author': 'Bjorlykke', 'year': '1971', 'journal-title': 'Norsk. geol. Tidsskr.'} / Norsk. geol. Tidsskr. / Petrology of Ordovician sediments in Wales by Bjorlykke (1971)
10.2475/ajs.278.1.1
10.1016/0024-4937(79)90062-8
10.1016/0148-9062(69)90011-4
10.1017/S0016756800034385
10.1306/74D71E10-2B21-11D7-8648000102C1865D
10.1180/claymin.1976.011.2.09
Weber K. 1980. Guide to excursion, Rheinisches Schiefergebirge, Gottingen.
{'key': 'S0016756800026066_ref017', 'volume-title': 'Clay Mineralogy of British Sediments', 'author': 'Perrin', 'year': '1971'} / Clay Mineralogy of British Sediments by Perrin (1971)
{'key': 'S0016756800026066_ref009', 'volume-title': 'Structural Geology', 'author': 'Dennis', 'year': '1972'} / Structural Geology by Dennis (1972)
{'key': 'S0016756800026066_ref013', 'first-page': '277', 'article-title': 'A new review of the chlorites', 'volume': '30', 'author': 'Hey', 'year': '1954', 'journal-title': 'Mineralog. Mag.'} / Mineralog. Mag. / A new review of the chlorites by Hey (1954)
10.1130/0016-7606(1978)89<1775:EOSCIR>2.0.CO;2 / Bull. geol. Soc. Am. / Evolution of slaty cleavage in relation to diagenesis and metamorphism: a study from the Hunsruckschiefer by Roy (1978)
10.1007/BF01802011
10.1180/claymin.1975.010.5.05
10.1016/S0016-7878(76)80009-0
10.1130/0016-7606(1976)87<725:MOBMOA>2.0.CO;2
10.1130/0016-7606(1978)89<1715:ACATTP>2.0.CO;2
10.1007/BF00372155
{'key': 'S0016756800026066_ref018', 'first-page': '355', 'article-title': 'Adjustment of land derived clays to the marine environment', 'volume': '27', 'author': 'Powers', 'year': '1957', 'journal-title': 'J. sedim. Petrol.'} / J. sedim. Petrol. / Adjustment of land derived clays to the marine environment by Powers (1957)
{'key': 'S0016756800026066_ref005', 'first-page': '634', 'article-title': 'Low-grade metamorphism in the Welsh Caledonides', 'volume': '138', 'author': 'Bevins', 'year': '1981', 'journal-title': 'J. geol. Soc. Lond.'} / J. geol. Soc. Lond. / Low-grade metamorphism in the Welsh Caledonides by Bevins (1981)

Dates

Type	When
Created	16 years, 3 months ago (May 1, 2009, 6:44 a.m.)
Deposited	6 years, 2 months ago (May 24, 2019, 5:18 p.m.)
Indexed	3 months, 1 week ago (May 13, 2025, 9:11 p.m.)
Issued	43 years, 3 months ago (May 1, 1982)
Published	43 years, 3 months ago (May 1, 1982)
Published Online	16 years, 3 months ago (May 1, 2009)
Published Print	43 years, 3 months ago (May 1, 1982)

Funders 0

None

BibTeX

@article{Craig_1982, title={Chlorite-mica stacks in low-strain rocks from central Wales}, volume={119}, ISSN={1469-5081}, url={http://dx.doi.org/10.1017/s0016756800026066}, DOI={10.1017/s0016756800026066}, number={3}, journal={Geological Magazine}, publisher={Cambridge University Press (CUP)}, author={Craig, J. and Fitches, W. R. and Maltman, A. J.}, year={1982}, month=may, pages={243–256} }

JSON

{
  "indexed": {
    "date-parts": [
      [
        2025,
        5,
        14
      ]
    ],
    "date-time": "2025-05-14T01:11:06Z",
    "timestamp": 1747185066549
  },
  "reference-count": 26,
  "publisher": "Cambridge University Press (CUP)",
  "issue": "3",
  "license": [
    {
      "start": {
        "date-parts": [
          [
            2009,
            5,
            1
          ]
        ],
        "date-time": "2009-05-01T00:00:00Z",
        "timestamp": 1241136000000
      },
      "content-version": "unspecified",
      "delay-in-days": 9862,
      "URL": "https://www.cambridge.org/core/terms"
    }
  ],
  "content-domain": {
    "domain": [],
    "crossmark-restriction": false
  },
  "published-print": {
    "date-parts": [
      [
        1982,
        5
      ]
    ]
  },
  "abstract": "<jats:title>Summary</jats:title><jats:p>Weakly deformed, low grade, Lower Palaeozoic metasediments from central Wales contain abundant stack-like intergrowths of chlorite and white mica that closely resemble stacks described from the Devonian Hunsruckschiefer of West Germany; the Ordovician Martinsburg Slate, New Jersey, U.S.A.; and elsewhere. Several theories have been proposed to explain the origin of such stacks, including a detrital origin; strain-controlled growth of chlorite on a detrital mica nucleus; and strain-controlled intergrowth during metamorphism. None of these satisfactorily explains the central Wales stacks. A detrital origin is precluded by the presence of many stacks with shapes too delicate to have survived transportation, and a lack of hydrodynamic equivalence between the stacks and the clastic host grains. Features inconsistent with strain-controlled growth are constant alignment parallel to bedding but non-systematic orientation with respect to tectonic cleavage, their common occurrence in undeformed rocks, and petrographic evidence that they precede the tectonic cleavage. It is proposed that the stacks formed during diagenesis and low-grade metamorphism, and before the onset of deformation, through mimetic growth on a primary bedding fabric composed of clay minerals.</jats:p>",
  "DOI": "10.1017/s0016756800026066",
  "type": "journal-article",
  "created": {
    "date-parts": [
      [
        2009,
        5,
        1
      ]
    ],
    "date-time": "2009-05-01T10:44:17Z",
    "timestamp": 1241174657000
  },
  "page": "243-256",
  "source": "Crossref",
  "is-referenced-by-count": 47,
  "title": "Chlorite-mica stacks in low-strain rocks from central Wales",
  "prefix": "10.1017",
  "volume": "119",
  "author": [
    {
      "given": "J.",
      "family": "Craig",
      "sequence": "first",
      "affiliation": []
    },
    {
      "given": "W. R.",
      "family": "Fitches",
      "sequence": "additional",
      "affiliation": []
    },
    {
      "given": "A. J.",
      "family": "Maltman",
      "sequence": "additional",
      "affiliation": []
    }
  ],
  "member": "56",
  "published-online": {
    "date-parts": [
      [
        2009,
        5,
        1
      ]
    ]
  },
  "reference": [
    {
      "key": "S0016756800026066_ref002",
      "volume-title": "Atlas of Rock Cleavage",
      "author": "Bayly",
      "year": "1977"
    },
    {
      "key": "S0016756800026066_ref021",
      "doi-asserted-by": "publisher",
      "DOI": "10.1002/gj.3350020311"
    },
    {
      "key": "S0016756800026066_ref016",
      "doi-asserted-by": "publisher",
      "DOI": "10.1144/gsjgs.138.4.0475"
    },
    {
      "key": "S0016756800026066_ref022",
      "first-page": "3",
      "article-title": "Gefugeuntersuchungen an transversalgeschieferten Gesteinen aus dem ostlichen Rheinischen Schiefergebirge (Ein Beitrag zur Genese der transversalen Schieferung)",
      "volume": "D 15",
      "author": "Weber",
      "year": "1976",
      "journal-title": "Geologisches Jahrbuch"
    },
    {
      "key": "S0016756800026066_ref012",
      "first-page": "245",
      "volume-title": "Conference Report: Deformation of soft sediments",
      "volume": "135",
      "author": "Fitches",
      "year": "1978"
    },
    {
      "key": "S0016756800026066_ref007",
      "doi-asserted-by": "publisher",
      "DOI": "10.1180/claymin.1976.011.2.08"
    },
    {
      "key": "S0016756800026066_ref006",
      "first-page": "123",
      "article-title": "Petrology of Ordovician sediments in Wales",
      "volume": "51",
      "author": "Bjorlykke",
      "year": "1971",
      "journal-title": "Norsk. geol. Tidsskr."
    },
    {
      "key": "S0016756800026066_ref004",
      "doi-asserted-by": "publisher",
      "DOI": "10.2475/ajs.278.1.1"
    },
    {
      "key": "S0016756800026066_ref003",
      "doi-asserted-by": "publisher",
      "DOI": "10.1016/0024-4937(79)90062-8"
    },
    {
      "key": "S0016756800026066_ref001",
      "doi-asserted-by": "publisher",
      "DOI": "10.1016/0148-9062(69)90011-4"
    },
    {
      "key": "S0016756800026066_ref019",
      "doi-asserted-by": "publisher",
      "DOI": "10.1017/S0016756800034385"
    },
    {
      "key": "S0016756800026066_ref008",
      "doi-asserted-by": "publisher",
      "DOI": "10.1306/74D71E10-2B21-11D7-8648000102C1865D"
    },
    {
      "key": "S0016756800026066_ref011",
      "doi-asserted-by": "publisher",
      "DOI": "10.1180/claymin.1976.011.2.09"
    },
    {
      "key": "S0016756800026066_ref023",
      "unstructured": "Weber K. 1980. Guide to excursion, Rheinisches Schiefergebirge, Gottingen."
    },
    {
      "key": "S0016756800026066_ref017",
      "volume-title": "Clay Mineralogy of British Sediments",
      "author": "Perrin",
      "year": "1971"
    },
    {
      "key": "S0016756800026066_ref009",
      "volume-title": "Structural Geology",
      "author": "Dennis",
      "year": "1972"
    },
    {
      "key": "S0016756800026066_ref013",
      "first-page": "277",
      "article-title": "A new review of the chlorites",
      "volume": "30",
      "author": "Hey",
      "year": "1954",
      "journal-title": "Mineralog. Mag."
    },
    {
      "key": "S0016756800026066_ref020",
      "doi-asserted-by": "crossref",
      "first-page": "1775",
      "DOI": "10.1130/0016-7606(1978)89<1775:EOSCIR>2.0.CO;2",
      "article-title": "Evolution of slaty cleavage in relation to diagenesis and metamorphism: a study from the Hunsruckschiefer",
      "volume": "89",
      "author": "Roy",
      "year": "1978",
      "journal-title": "Bull. geol. Soc. Am."
    },
    {
      "key": "S0016756800026066_ref014",
      "doi-asserted-by": "publisher",
      "DOI": "10.1007/BF01802011"
    },
    {
      "key": "S0016756800026066_ref010",
      "doi-asserted-by": "publisher",
      "DOI": "10.1180/claymin.1975.010.5.05"
    },
    {
      "key": "S0016756800026066_ref026",
      "doi-asserted-by": "publisher",
      "DOI": "10.1016/S0016-7878(76)80009-0"
    },
    {
      "key": "S0016756800026066_ref015",
      "doi-asserted-by": "publisher",
      "DOI": "10.1130/0016-7606(1976)87<725:MOBMOA>2.0.CO;2"
    },
    {
      "key": "S0016756800026066_ref025",
      "doi-asserted-by": "publisher",
      "DOI": "10.1130/0016-7606(1978)89<1715:ACATTP>2.0.CO;2"
    },
    {
      "key": "S0016756800026066_ref024",
      "doi-asserted-by": "publisher",
      "DOI": "10.1007/BF00372155"
    },
    {
      "key": "S0016756800026066_ref018",
      "first-page": "355",
      "article-title": "Adjustment of land derived clays to the marine environment",
      "volume": "27",
      "author": "Powers",
      "year": "1957",
      "journal-title": "J. sedim. Petrol."
    },
    {
      "key": "S0016756800026066_ref005",
      "first-page": "634",
      "article-title": "Low-grade metamorphism in the Welsh Caledonides",
      "volume": "138",
      "author": "Bevins",
      "year": "1981",
      "journal-title": "J. geol. Soc. Lond."
    }
  ],
  "container-title": "Geological Magazine",
  "original-title": [],
  "language": "en",
  "link": [
    {
      "URL": "https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800026066",
      "content-type": "unspecified",
      "content-version": "vor",
      "intended-application": "similarity-checking"
    }
  ],
  "deposited": {
    "date-parts": [
      [
        2019,
        5,
        24
      ]
    ],
    "date-time": "2019-05-24T21:18:52Z",
    "timestamp": 1558732732000
  },
  "score": 1,
  "resource": {
    "primary": {
      "URL": "https://www.cambridge.org/core/product/identifier/S0016756800026066/type/journal_article"
    }
  },
  "subtitle": [],
  "short-title": [],
  "issued": {
    "date-parts": [
      [
        1982,
        5
      ]
    ]
  },
  "references-count": 26,
  "journal-issue": {
    "issue": "3",
    "published-print": {
      "date-parts": [
        [
          1982,
          5
        ]
      ]
    }
  },
  "alternative-id": [
    "S0016756800026066"
  ],
  "URL": "http://dx.doi.org/10.1017/S0016756800026066",
  "relation": {},
  "ISSN": [
    "0016-7568",
    "1469-5081"
  ],
  "subject": [],
  "container-title-short": "Geol. Mag.",
  "published": {
    "date-parts": [
      [
        1982,
        5
      ]
    ]
  }
}