Multiple episodes of sand injection leading to accumulation and leakage of hydrocarbons along the San Andreas/San Gregorio fault system, California

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This is a non-peer reviewed pre-print. The Manuscript is currently under review in Marine and Petroleum Geology. Please note the subsequent version of this manuscript may have a different content. 2011). Pore-fluid is generally driven upward following the pressure gradients that form 162 between high-pressured zones in the shallow crust, typically at depths of less than 1.5 km 163 burial and the Earth's surface (Vigorito and Hurst, 2010;Hurst et al., 2011). 164 Variations in pore-fluid pressure within the host strata and the underlying pressure cell unit, it has been demonstrated that intrusions tend to fill pre-existing tectonic structures, and 182 that they predominantly form low to high angle dikes in tectonically active areas (Galland et 183 al., 2003;2007;Ferre' et al., 2012;Palladino et al., 2016;2018) (Fig. 2b). Flat-lying intrusive 184 geometries are still possible in compressional settings when the maximum principal stress (σ1) This is a non-peer reviewed pre-print. The Manuscript is currently under review in Marine and Petroleum Geology. Please note the subsequent version of this manuscript may have a different content.
Sills mainly crop-out at Panther Beach/Yellowbank Creek, while small-scale sills also 234 occur at 4 Mile Beach (Fig. 1). Sills typically display low-angle (<5º) discordance with 235 bedding (Fig. 4) Saucer-shaped, tar-saturated sandstone intrusions are very well exposed at 4 Mile 253 Beach (Fig. 1). In cross-section, they consist of an inner bedding-parallel sandstone intrusion 254 that are connected laterally with two outer sills by means of segments inclined at between 15° 255 and 60°. Similar features observed on seismic images are often referred to as wings (Huuse et 256 al., 2007, Jackson et al., 2011. Inner sills, that are typical of large saucer-shaped intrusions, This is a non-peer reviewed pre-print. The Manuscript is currently under review in Marine and Petroleum Geology. Please note the subsequent version of this manuscript may have a different content.
intrusions coalesce to form a composite intrusion with "petals of a flower" geometry, which 259 are connected by smaller, contemporaneous dikes. Bifurcation and convergence of the saucers 260 is characteristic (Fig. 4c, d). A nested geometry of saucers occurs where smaller intrusions 261 overlie large saucers and are linked by dikes with cuspate geometry (Fig. 4e,   pockmark is preserved, which is fed by numerous low-and high-angle to bedding dykes. This is a non-peer reviewed pre-print. The Manuscript is currently under review in Marine and Petroleum Geology. Please note the subsequent version of this manuscript may have a different content.
In order to investigate the relationships that exist between tectonic structures and 309 sandstone intrusions, a detailed structural survey has been carried out in five key outcrop

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In the previous sections we described the main characteristics and spatial distribution Miocene onwards (Fig. 14). Although these two events involved the same stratigraphic unit, 563 i.e. the Santa Cruz Mudstone, the mechanical response of the sedimentary sequence and the 564 regional tectonic controls varied between the two injection events thereby resulting in 565 sandstone intrusions displaying different characteristics.

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The first injection event (Fig. 14a)   This is a non-peer reviewed pre-print. The Manuscript is currently under review in Marine and Petroleum Geology. Please note the subsequent version of this manuscript may have a different content.