Paleomagnetism and geochronology of late Paleozoic granitic rocks from the Lake District of southern Chile: Implications for accretionary tectonics

Journal Article · Mon Apr 01 04:00:00 UTC 1991 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1991)019<0332:PAGOLP>2.3.CO;2· OSTI ID:5657185

Beck, Jr, M E; Alfredo, G R; Burmester, R F ^[1]; Francisco, M H; Francisco, H A ^[2]; Drake, R E ^[3]

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1. Western Washington Univ., Bellingham (USA)
2. Universidad de Chile, Santiago (Chile)
3. Berkeley Geochonology Center, Berkeley, CA (USA)

K/Ar and {sup 40}Ar/{sup 39}Ar dating shows that granite rocks in the central Lake District, southern Chile, are late Paleozoic. Granitic rocks of similar age extend far up the coast of Chile, perhaps as much as 1800 km. The authors have obtained paleomagnetic directions from seven sites near Lago Ranco; these give a paleomagnetic pole at lat 57.4{degree}S, long 323.5{degree}E, with a circle of 95% confidence of 18.8{degree}. This is not significantly different from the mean late Paleozoic reference pole for the South American craton. If these results are characteristic of the late Paleozoic belt as a whole, it follows that post-late Plaeozoic accretion and terrane displacement are absent throughout much of the central Andes.

• OSTI ID: 5657185
• Journal Information: Geology; (USA), Journal Name: Geology; (USA) Vol. 19:4; ISSN GLGYB; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
ALKALI METAL ISOTOPES
ANDES
ARGON 39
ARGON 40
ARGON ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHILE
COORDINATES
DEVELOPING COUNTRIES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOMAGNETIC COORDINATES
GRANITES
IGNEOUS ROCKS
ISOTOPE DATING
ISOTOPE RATIO
ISOTOPES
LATIN AMERICA
LIGHT NUCLEI
MAGNETISM
MOUNTAINS
NUCLEI
PALEOMAGNETISM
PALEOZOIC ERA
PLUTONIC ROCKS
POTASSIUM ISOTOPES
RADIOISOTOPES
REGIONAL ANALYSIS
ROCKS
SOUTH AMERICA
STABLE ISOTOPES
TECTONICS
YEARS LIVING RADIOISOTOPES