A paleomagnetic pole position for the Franklin Mountains Precambrian sequence, Texas
- Univ. of Texas, El Paso, TX (United States). Dept. of Geological Sciences
The Franklin Mountains, West Texas, contain a well preserved sequence of Proterozoic rocks that were probably formed on the southern margin of the Proterozoic North American continent. This sequence includes, in ascending order, the Castner Marble, the basaltic Mundy Breccia, quartzites and hornfels of the Lanoria Formation, and meta-sedimentary and meta-volcanic units of the Thunderbird Group. The lower part of this sequence is intruded by several phases of the 1.1 Ga Red Bluff Granite complex. Oriented paleomagnetic core samples were collected from the Castner Marble, the Mundy Breccia, and a quartz syenite phase of the Red Bluff Granite complex, in order to determine pole positions for each individual unit. Intensive demagnetization studies revealed that primary magnetic directions of both the Castner Marble and the Mundy Breccia have been totally overprinted by the Red Bluff intrusive event. Therefore, the following 1.1 Ga paleopole is based on combined tilt corrected data from the Castner Marble, Mundy Breccia and the Red Bluff Granite quartz syenite phase: Dec. = 288.8, Inc. = 52.7 (N = 87, R= 78.42, a[sub 95] = 5.05[degree], k = 10.02) Pole long. = 174.4[degree] W, Pole lat. = 31.3[degree] N (dp = 4.8, dm = 7.0). This pole is indistinguishable from 1.1 Ga Keweenawan Rift paleopoles.
- OSTI ID:
- 6137767
- Report Number(s):
- CONF-9303212-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:1; Conference: 27. annual Geological Society of America (GSA) South-Central Section meeting, Fort Worth, TX (United States), 15-16 Mar 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GEOLOGIC FORMATIONS
PALEOMAGNETISM
TEXAS
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOMAGNETIC FIELD
GRANITES
HORNFELSES
MARBLE
PRECAMBRIAN ERA
QUARTZITES
SYENITES
DEVELOPED COUNTRIES
GEOLOGIC AGES
IGNEOUS ROCKS
MAGNETIC FIELDS
MAGNETISM
METAMORPHIC ROCKS
NORTH AMERICA
PLUTONIC ROCKS
ROCKS
USA
580000* - Geosciences