WELDED BRECCIAS IN ANDESITE LAVAS

Authors
SPARKS RSJ STASIUK MV GARDEWEG M SWANSON DA
Citation
Rsj. Sparks et al., WELDED BRECCIAS IN ANDESITE LAVAS, Journal of the Geological Society, 150, 1993, pp. 897-902
Citations number
16
Categorie Soggetti
Geosciences, Interdisciplinary
Journal title
Journal of the Geological Society → ACNP
ISSN journal
00167649
Volume
150
Year of publication
1993
Part
5
Pages
897 - 902
Database
ISI
SICI code
0016-7649(1993)150:<897:WBIAL>2.0.ZU;2-M
Abstract
Flow breccias, formed al the margins of blocky andesite lavas, can be reheated, welded and sometimes deformed to form rocks reminiscent of w elded pyroclastic rocks. Reheating occurs due to advection of heat fro m the flow to the basal breccias. Surface breccias also infill extensi onal crevasses which are later closed and compressed. Strongly deforme d welded breccia bands form within the flow levees. The angular brecci a clasts can be deformed into fiamme.