Paleotectonics of a complex Miocene half graben formed above a detachment fault: The Diligencia basin, Orocopia Mountains, southern California

The Diligencia basin in the Orocopia Mountains of southeastern California has been one of the primary areas used to test the hypothesis of more than 300 km of dextral slip along the combined San Andreas/San Gabriel fault system. The Orocopia Mountains have also been the focus of research on deposition, deformation, metamorphism, uplift and exposure of the Orocopia Schist, which resulted from fl at-slab subduction during the latest Cretaceous/Paleogene Laramide orogeny. The uppermost Oligocene/Lower Miocene Diligencia Formation consists of more than 1500 m of nonmarine strata, including basalt fl ows and intrusions dated at 24-21 Ma. The base of the Diligencia Formation sits nonconformably on Proterozoic augen gneiss and related units along the southern basin boundary, where low-gradient alluvial fans extended into playa-lacustrine environments to the northeast. The northern basal conglomerate of the Diligencia Formation, which was derived from granitic rocks in the Hayfield Mountains to the north, sits unconformably on the Eocene Maniobra Formation. The northern basal conglomerate is overlain by more than 300 m of mostly red sandstone, conglomerate, mudrock and tuff. The basal conglomerate thins and fines westward; paleocurrent measurements suggest deposition on alluvial fans derived from the northeast, an interpretation consistent with a NW-SE-trending normal fault (present orientation) as the controlling structure of the half graben formed during early Diligencia deposition. This fault is hereby named the Diligencia fault, and is interpreted as a SW-dipping normal fault, antithetic to the Orocopia Mountains detachment and related faults. Deposition of the upper Diligencia Formation was infl uenced by a NE-dipping normal fault, synthetic with, and closer to, the exposed detachment faults. The Diligencia Formation is nonconformable on Mesozoic granitoids in the northwest part of the basin. Palinspastic restoration of the Orocopia Mountain area includes the following phases, each of which corresponds with microplate-capture events along the southern California continental margin: (1) Reversal of 240 km of dextral slip on the San Andreas fault (including the Punchbowl and other fault strands) in order to align the San Francisquito-Fenner-Orocopia Mountains detachment-fault system at 6 Ma. (2) Reversal of N-S shortening and 90° of clockwise rotation of the Diligencia basin and Orocopia Mountains, and 40 km of dextral slip on the San Gabriel fault between 12 and 6 Ma. (3) Reversal of 40° of clockwise rotation of the San Gabriel block (including Soledad basin and Sierra Pelona) and 30 km of dextral slip on the Canton fault between 18 and 12 Ma. These palinspastic restorations result in a coherent set of SW-NE-trending normal faults, basins (including Diligenica basin) and antiformal structures consistent with NW-SE-directed crustal extension from 24 to 18 Ma, likely resulting from the unstable configuration of the Mendocino triple junction

Econophysics — complex correlations and trend switchings in financial time series

This article focuses on the analysis of financial time series and their correlations. A method is used for quantifying pattern based correlations of a time series. With this methodology, evidence is found that typical behavioral patterns of financial market participants manifest over short time scales, i.e., that reactions to given price patterns are not entirely random, but that similar price patterns also cause similar reactions. Based on the investigation of the complex correlations in financial time series, the question arises, which properties change when switching from a positive trend to a negative trend. An empirical quantification by rescaling provides the result that new price extrema coincide with a significant increase in transaction volume and a significant decrease in the length of corresponding time intervals between transactions. These findings are independent of the time scale over 9 orders of magnitude, and they exhibit characteristics which one can also find in other complex systems in nature (and in physical systems in particular). These properties are independent of the markets analyzed. Trends that exist only for a few seconds show the same characteristics as trends on time scales of several months. Thus, it is possible to study financial bubbles and their collapses in more detail, because trend switching processes occur with higher frequency on small time scales. In addition, a Monte Carlo based simulation of financial markets is analyzed and extended in order to reproduce empirical features and to gain insight into their causes. These causes include both financial market microstructure and the risk aversion of market participants