HR: 1340h
AN: T43A-1094    [Abstracts]
TI: Damaged Cave Deposits in Haifa: Evidence for Destructive Earthquakes from the Carmel Fault
AU: Braun, Y
EM: yaelsy@hotmail.com
AF: The Hebrew University, Institute of Earth Sciences, Jerusalem, 91904, Israel
AU: Braun, Y
EM: yaelsy@hotmail.com
AF: The Geological Survey, Malkhei Yisrael 30, Jerusalem, 95501, Israel
AU: Bar-Matthews, M
EM: matthews@mail.gsi.gov.il
AF: The Geological Survey, Malkhei Yisrael 30, Jerusalem, 95501, Israel
AU: Ayalon, A
EM: ayalon@mail.gsi.gov.il
AF: The Geological Survey, Malkhei Yisrael 30, Jerusalem, 95501, Israel
AU: Kagan, E
EM: elisa.kagan@mail.huji.ac.il
AF: The Hebrew University, Institute of Earth Sciences, Jerusalem, 91904, Israel
AU: Kagan, E
EM: elisa.kagan@mail.huji.ac.il
AF: The Geological Survey, Malkhei Yisrael 30, Jerusalem, 95501, Israel
AU: * Agnon, A
EM: amotz@huji.ac.il
AF: The Hebrew University, Institute of Earth Sciences, Jerusalem, 91904, Israel
AB: A study conducted in a cave located in the Mount Carmel region (Denya Cave), shows that broken speleothems can provide evidence for damage related to ancient earthquakes on the Carmel fault. Following the work of Kagan et al. (2005) in the Judean Hills, in which accurate 234U/ 230Th ages of collapsed speleothems were consistent with independent evidence for strong earthquakes, we present here initial results from the Denya Cave. Mt. Carmel is a manifestation of tectonic movements in the north of Israel. It is a continental uplift of more than 800m above sea level. It is defined by the northwestern to north-northwestern trending Carmel fault, a branch of the Dead Sea transform system, and continues into the Mediterranean continental shelf (Hofstetter et al., 1989). The fault has been active since the Miocene and activity during the Pleistocene is evident, and yet very little is known about the extent of its seismic activity during the Quaternary (Gluck, 2002). The region of Mt. Carmel features abundant karst , which can be used in a comprehensive paleo-seismological study of the Carmel fault . The Denya cave is situated on the southern side of the mountain on a spur sloping to the west from the summit of Mount Carmel, toward the town of Tirat Ha-Carmel. Work in Denya Cave, up to this stage includes detailed mapping and initial collection of speleothem samples suspected of being seismites (broken or deformed speleothems that could result from seismic activity), and their dating using the 234U/ 230Th method. Measurements for dating are conducted on the Multiple Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICP-MS) in the Geological Survey of Israel. The age of one seismic event, as evident from three damaged stalagmite samples, is ca. 11ka. This age was determined for post- and pre-collapse laminae. Five ages of ca. 10ka were obtained from other seismites and it is not clear yet whether they represent the same event or a subsequent one. A cluster of older events between 14-18ka was identified in five samples and further study is needed in order to verify whether this range of ages represent clustering of several events. No indications in the cave were yet identified for seismic activity younger than the ages of 10-11ka obtained. Excluding archaeological indications for damage from Tel Megiddo (Marco et al., 2006), these ages are the youngest known for paleoseismicity on the Carmel fault to date.
DE: 1120 Isotopic disequilibrium dating
DE: 4958 Speleothems
DE: 7221 Paleoseismology (8036)
DE: 7250 Transform faults
DE: 8036 Paleoseismology (7221)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting