POSSIBLE EFFECTS OF CHICXULUB AND CHESAPEAKE – TOMS RIVER ASTEROID IMPACT EVENTS ON HYDROCARBON ENTRAPMENTS – BALTIMORE CANYON OFFSHORE US
Impact-induced far-field (ITFF) crustal-strain fields are caused by refracted shock waves surface, shear (S) and compressional (P-) waves returning to the surface at remote distances off the asthenosphere (660km.), lower mantle(1600km.), and outer Core (2900km.)
Chicxulub and Chesapeake impacts with calculated seismic events of 10.3 and 8 respectively. The Baltimore Canyon is within Impact-tectonic far-field strain fields (ITFF) of the Chicxulub (2900km.) and Chesapeake Bay / Toms River (660km.). The area contains overlapping ITFF from the three respective impacts.
Strewn fields are documented in cores as micro-tektites spherules from 1) Cretaceous/Paleocene (65-66) Ma the Chicxulub impact U.S. East Coast and offshore, DSDP 603, ODP Leg 174 AX, 2) and the Chesapeake Bay Impact Late Eocene (35 Ma) DSDP 612, 902,903.
In the Baltimore Canyon Trough( BCT), offshore US, the interior shelf structural belt formed during the Lower Cretaceous, highlighted by the emplacement of the Great Stone Dome intrusion. Faulting to the top of the Eocene reflected in well correlation cross-sections and seismic lines. Exploration drilling has encountered migrated gas in Cretaceous and Jurassic age rocks, evidenced by the diamandoids generated at much deeper depths. The thermal maturation modelling , and core samples, shows gas generation from Jurassic age rocks since 120 Ma Both the Chicxulub CBI and Toms River Impacts caused reactivation of fault planes, salt mobilization, and the hydrocarbons expulsion in previously trapped reservoirs.
In the BCT, twenty eight dry holes out of thirty two wells were drilled. BOEM’s assignment of an extremely low probability of success .10 attests to trap risk, whereas overall petroleum system abilities .72, suggesting capabilities in generation and expulsion with reservoir presence.