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In previous palaeoclimatic models, the Kimmeridgian stage has been defined as a typical greenhouse-time interval with weak latitudinal gradients. However, palaeoclimatic information based on biogenic low-Mg calcite 6180 for the Kimmeridgian is still limited. Here, shell materials (n = 81) precipitated by brachiopods, oysters and Trichites bivalves from the Lower Saxony Basin, Northern Germany are evaluated for their potential to act as archive for marine sea-surface temperatures. Furthermore, the associated clay mineral assemblages based on bulk materials are used to infer hinterland weathering patterns and overall climatic conditions simultaneously. The established sea-surface temperature curve reveals an overall slightly warming trend through the Kimmeridgian. Weak seasonality (similar to 4 degrees C) in sea-surface temperatures is documented by oxygen isotope variations measured along the growth lines of a large Trichites shell. Distinctly higher delta O-18 values observed in the Lower Kimmeridgian (late Baylei Chron) are interpreted to be related to the short-term influx of cooler boreal water masses. Judging from the corresponding smectite-dominated interval, however, the positive oxygen isotope anomaly may also be partly explained by a relatively drier climate causing enhanced delta O-18(seawater) values due to intensified evaporation. The kaolinite/(illite + chlorite) ratio points to a slightly long-term decrease in humidity through the Kimmeridgian on the landmasses surrounding the LSB. The short-term fluctuations in humid/arid conditions correlate significantly with sea-level changes, with humid climates accompanying high sea-levels and arid climates accompanying low sea-levels. Results from this study provide new insights into Late Jurassic climatic dynamics and help to establish a reliable Subboreal Late Jurassic sea-surface temperature curve.